Biology ebook2

ZOOLOGICAL ANATOMY AND PHYSIOLOGY EBOOK

BY S0112493

BIOLOGICAL PRINCIPLES

INTRODUCTION TO BIOLOGY A living organisms can be classified into different orders, classes and families this is done by the characteristics it contains. These groups are the further divided into genus and species which then describes an individual types of organism (MRCVS et al., 2009b, pp. 15 – 19) The body is made up of number of different systems of which have very unique functions, it’s these systems which provide a structural framework of the body (Boyle, 2008, pp. 2 – 6) Each system consists of a collection of tissues and organs which are made up by the smallest units within the body- the cells Cells are so tiny they can only be seen under a microscope and all have the same basic structure but ae all made up of different formulas of atoms and molecules which determines their specific function (Boyle, Indge and Kathryn, 2002, pp. 313 – 316).

Each structure of the cell play a huge part within the body, and ensure the cell and most of the body system functions correctly (Campbell, Reece and Reece, 2001) Cells grow and divide by means of mitosis, this is defined as the one cell breaks down and divides into two identical daughter cells which contains the correct number of chromosomes (MRCVS et al., 2009a, pp. 177 – 179).

The body contains 60-70% water and it has to functions, surrounds the cells within the body also known as extracellular fluid and also within the cells known as intracellular.

It is this water that moves between compartments within the body and this is controlled by the chemical component’s within the fluid which were formed during the process of diffusion and osmosis (MRCVS et al., 2009b, pp. 15 – 16) Bodily fluids contain organic and inorganic

compounds.

The

structure and percentage of all of these in essential to balance and keep the normal function of the SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

1

body. Many body systems are involved in the maintenance and balance for normal function, this process is known as homeostasis (Cohen, 2000).

This eBook will provide you with information on the structure of the different cells within the animals body, their structure and how this is achieved and the function of these individual cells, you will also learn how protein is produced with the body and why and how this important for normal body function. You will also learn about the variation of tissues within the body and their individual tasks and how they contribute to keeping equilibrium within the body as well as how these tissue help form larger internal organs such as the heart, kidneys, and lungs and how each of the body systems work in conjunction with one another to sustains maintenance for survival and life.

This publication can also be viewed online at http://issuu.com/laura8339/docs/biology-_ebook

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

2

Table of Contents INTRODUCTION

1

CHAPTER 1: ANIMAL CELLS PROKARYOTE CELLS

4

EUKARYOTE CELLS

5

CHAPTER 2: PROTEIN PRODUCTION

11

CHAPTER 3: TISSUES

16

CHAPTER 4: ORGANS

25

CHAPTER 5: SYSTEMS

31

CHAPTER 6: ANIMAL PHYSIOLOGY & HOMEOSTSTIC CONTROL

39

CONCLUSION

48

BIBLIOGRAPHY

50

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

3

CHAPTER 1 ANIMAL CELLS INTRODUCTION TO ANIMAL CELLS Cells are small units of tissue which man only be seen under a microscope (Aspinall V, Cappello M, 2009). Cells are known to be the basic structure and functional unit for all living organisms. These functions may include taking in nutrients and excreting wastes, respiration and reproduction (Boyle and Kathryn, 2008, pp. 311 – 315). Within the cell there are organelles which can be referred to as “little organs” which float within the cytoplasm of the cell and it’s these organelles which determine the function in which that cell is to carry out (Boyle, 2008, pp. 177 – 178) This chapter will show you the different organelles within two different types of cell which are within the body and how theses individual organelles contribute to the cells movement and performing their desired job or task.

All animal cell consists of many organelles that are needed in order for the cell to function ranging from the nucleus, plasma membrane, to lysosomes.

There are two different types of cells, these are identified as; 

Prokaryote cells



Eukaryote Cells

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

4

1.1 PROKARYOTE CELLS Prokaryote

cells

are

microscopic

single-celled organisms. Prokaryote cells lack a membrane-bound nucleus and other internal structures and are therefore ranked among the unicellular life-forms called prokaryotes (favor, 2004). A key example of a prokaryote is

bacteria.

The

prokaryote

cell

consists of several components;

Figure 1 Structure of Prokaryote Cells

Nucleoid- The nucleoid has an irregular shape compared to the nucleus of eukaryotic cells, which is circular. The nucleoid is responsible for storing RNA and DNA material.

It is this DNA which enable the cell to maintain its structure and shape.

Cell Wall: Cell walls are made up of Murein and other organic molecules such as proteins, carbohydrates and lipids. Its main function is Protects the cell and provide shape and definition.

Outer Membrane: Protects the cell against some antibiotics by having a permeable membrane which separates the prokaryotic periplasm from its surroundings Cell Membrane: The plasma membrane is a double-layer of phospholipids made up of proteins and other molecules. It is essentially the “bag� that holds all of the intracellular material and regulates the movement of materials into and out of the cell.

Also contains enzymes important to cellular respiration Cytoplasm: A gel-like substance composed mainly of water that also contains enzymes, salts, cell components, and various organic molecules and is found within the plasma membrane. Contains DNA, ribosomes, and organic compounds required to carry out life processes.

Chromosome: carries genetic information inherited from past generations Plasmid: plasmid is a non-essential piece of DNA that have a great advantage to the bacteria, such as antibiotic resistance, virulence (the ability to cause disease) and

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

5

conjugation (a bacterium’s ability to share its plasmids with other bacteria). Plasmids are also found in some eukaryotic microbes.

Capsule, and slime layer: Found in some bacterial cells, this additional outer covering protects the cell when it is engulfed by other organisms, assists in retaining moisture, protects the cell and assist in attaching the cell to other surfaces Ribosomes: these float within the cytoplasm and this is the main site for protein synthesis within the cell.

Endospore: protects the cell against harsh environmental conditions, such as heat or drought.

Pilus (Pili) assist the cell in attaching to other surfaces or cells, which is important for genetic recombination.

Flagellum: Long, whip-like tail that aids in movement and helps transport the cell around the body.

1.2 EUKARYOTE CELLS Eukaryote cells is any organism whose cells contain a nucleus and other organelles enclosed within a membrane.

Eukaryote

cells

have

different

structure

comparison

to

a in

Prokaryote

cells and contain different components.

Nucleus The

most

prominent

organelle in an animal cell is normally the nucleus. The nucleus contains most of the genes that control the cell. As is known as the information Figure 2: Eukaryote cell (Anonymous, 2013)

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

6

centre of the cell (MRCVS et al., 2009b, pp. 15 – 16). The nuclear envelope encloses the nucleus, separating the contents from the cytoplasm. This envelope is a double membrane, made up of a lipid bilayer with associated proteins. The nuclear side of the envelope is lined by the nuclear lamina, which is a netlike array of protein filaments that keep the shape of the nucleus. Also within is the chromatin, a material that organises DNA and proteins (Johnson, 2007, pp. 177 – 186). There are two different levels of density for chromatin, the first being a dark staining chromatin which consists of tightly packed DNA is commonly identified as hetrochromatin, the second being a lighter, more loosely packed materials is called euchromatin (Boyle and Kathryn, 2008, pp. 311 – 315) When the cells beginnings to reproduce, the chromatin condenses becoming thick separate structures know as chromosomes.

Plasma Membrane The plasma membrane is composed of a phospholipid bilayer, which is two layers of phospholipids back to back. Phospholipids are lipids with a phosphate group attached to them. The phospholipids have one head and two tails (Campbell, Reece and Reece, 2001) The plasma membrane is the boundary between the cell and its environment and regulates what enters and exits the cell. Cells must maintain an appropriate amount of molecules to function inside them. They must also have a way to keep things out or to allow things to enter (Boyle, 2008, pp. 34 – 54).

Ribosomes Ribosomes are small dense organelles usually about 20nm in diameter (Boyle, 2008, pp. 34 – 54) and are present in large quantities within the cell, many are attached to the rough surface of the endoplasmic reticulum (Johnson, 2007, pp. 177 – 186).

Ribosomes main functioning purpose is protein synthesis in the cytoplasm, .this involves the assembly of amino acids in the correct formation to produce new proteins.

Free ribosomes function in the cytosol, while bound ribosomes generally make proteins that are for inclusion into the membrane, packaging, or for export from the cell.

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

7

Endoplasmic Reticulum Endoplasmic reticulum makes up more than half the membrane of the cell. There are two different kinds of endoplasmic reticulum: smooth and rough (Campbell, Reece and Reece, 2001). Smooth endoplasmic reticulum appears to be smooth because it lacks ribosomes on the cytoplasmic surface, its main purpose is steroid production (also known as a lipid hormone), however the Smooth endoplasmic reticulum also contains enzymes detoxify a wide variety of molecules as well as acting as a storage site for calcium (Boyle, Indge and Kathryn, 2002, pp. 11 – 12). Yet the other endoplasmic reticulum appears rough because ribosomes stud the cytoplasmic surface. The main function of the rough endoplasmic reticulum is to hold together and transport proteins made on the ribosomes (Boyle, Indge and Kathryn, 2002, pp. 11 – 12).

Golgi Body After leaving the endoplasmic reticulum, many transport vesicles travel to the Golgi body. This consists of flattened membranous sacs and is known as the centre of manufacturing, warehousing, sorting and shipping (Boyle, M et al, 2008). Here the products of the endoplasmic reticulum are modified and sorted then sent to their destination (Boyle, M et al, 2008). Also responsible for the formation of lysosomes and modification of some proteins (Aspinall, Cappello, 2009).

Microvilli Microvilli are tiny hair like folds in the plasma membrane that extend from the surface of many absorptive or secretory cells. Microvilli have a wide variety of functions, including absorption, secretion and cellular division. Microvilli are also of importance on the cell surface of white blood cells, as they aid in the migration of white blood cells.

Centrosome Centrosome is an organelle that is the main place where cell microtubules get organised. They occur only in animal cells. Also, it regulates the cell division cycle, the stages which lead up to cell division.

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

8

Lysosomes Lysosomes are membrane-enclosed sac of hydrolytic enzymes that are made by rough endoplasmic reticulum

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

9

Cytoskeleton The cytoskeleton is constructed from proteins that help to define the cells shape, provide support, and aid the movement of the cell (Bemis et al., 2006, pp. 56 – 57).

Cilia and Flagella A special arrangement of microtubules is responsible for the eating of the flagella and cilia. Cilia normally occurs in large number on the cell surface. Flagella are the same length in diameter but longer. These are responsible for locomotive appendages that protrude from some cells. Many unicellular organisms are propelled through water by cilia and flagella.

The outer shell of each is cell is made up of a plasma membrane. The membrane at the boundary of every cell that acts as a selective barrier, thereby regulating the cells chemical composition.

Every cell uses all components, no one piece can make the cell function alone. Most organelles are interwoven and work based on the work performed by other units in the cell.

COMPARISON OF PROKARYOTE AND EUKARYOTE CELLS Prokaryotes

and

Eukaryote cells have few similarities which include

both

membrane

being bound,

both have ribosomes for

Figure 3 Comparison of Prokaryotic and Eukaryotic Cells

protein

productions.

They

both

DNA

which

contain

contains

genetic material and both the cells have very similar metabolisms, however these cells differ in many ways (Johnson, 2007, pp. 177 – 186).

Prokaryotes cells are made up of sugar and amino acids, much smaller in size, DNA freely float around. Prokaryotes cells divide by binary fission or simple cell division and

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

10

the organelles are not membrane bound. A prime example of Prokaryotes cells are bacteria and archaeans (Alberts, Johnson and Walter, 2008 Eukaryote cells have both a nucleus and nucleolus and share much larger in size compared to Prokaryote cells. DNA is held within the nucleus and uses mitosis to divide and transport molecules. Eukaryote cells have membrane bound organelles and an example of this type of cell is a fungi (Boyle, Indge and Kathryn, 2002, pp. 11 – 12)

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

11

CHAPTER 2 PROTEIN PRODUCTION

INTRODUCTION The body can make its own proteins, proteins are essential for the body and they play a key role in enabling the animal to survive (Darnell, Lodish and Baltimore, 1990), this is achieved through a chemical reaction known as protein synthesis. This is a very complex process which uses a variety of different components such as DNA, RNA, amino acids and enzymes (Graham and Wilcox, 2002b) (These will be discussed and broken down further in this chapter to make it easier to understand). The first thing you need to understand is the structure and function of proteins.

Proteins

are

macro

molecules

made up of a number of amino acids that are structured into a liner chain and are held tightly together by a covalent bond, this linear sequence

is

known

as

a

polypeptide chain (Cui, 2005b).

It is these proteins that are used to

Figure 4 Structure of Protein, Source: (DEMUTH, 2005)

make almost everything in the body including cells, tissue and body organs and systems (Dodds and Laverdure, 2012).

Proteins are used in a variety of other ways, their main job roles include; Transporter for oxygen- carries haemoglobin which is a blood protein that is essential for supplying the cells with oxygen Hormones- many of the bodies’ hormones such as progesterone and insulin are made from proteins Locomotion- protein within the muscles known as myoglobin enable the animal to be able to move to enable movement used for daily activities such as swimming, running and walking.

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

12

Transport system for nutrients- proteins bind to substances within the body and carry them to desired locations within the body Enzymes Production- all enzymes are made up of proteins and the enzymes play a key role in bringing about chemical reactions within the body.

Structural Repair- proteins make up the animals body structure, these include skin, cartilage, and keratins which are also responsible for the formation of skin, fur and nails Converter- proteins also have the ability to convert into sugar or fat and be used within the body as fuel to provide the animal with an energy source. (Reece, Taylor and Simon, 2011) Protein contains genetic material which are known as DNA and RNA DNA is known as Deoxyribonucleic acid and is made up of small molecules known as nucleotides, a nucleotide is a five carbon

sugar

molecule

which

attaches itself to the phosphate group

(which

makes

up

the

backbone of the helix) and an organic base (Gupta, 2008). The four organic bases are which can be identified as Thymine (T), Adenine (A),Cytosine (C) and Guanine (G), which enable then to form a chain , please refer to Figure 5 The Four

Figure 5 The Four Nucleotide Subunits That Make up DNA, Source: (Johnson and Losos, 2007, pp. 214 – 218)

Nucleotide Subunits That Make up DNA .

However certain pairs will always attract and connect using hydrogen bonds, for example A with T and C with G, and these become known as called base pairs (Gupta, 2008).

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

13

Nucleotides are arranged in two long strands, it’s the winding of these two strands which form a double helix (Todd, 2013). The structure very similar to that of a ladder with the base pairs forming the ladder’s rungs and the sugar and phosphate molecules forming the vertical sidepieces of the ladder, the structure of these bases determines the

genetic

information

for

the

function and desired destination of the protein Bailey, 2015), please see Figure 6 Structure of DNA below.

Figure 6 Structure of DNA, Source: National Institutes of Health, Department of Health & Human Services, 2015)

RNA or Ribonucleic acid is it is also known is single-stranded. RNA is part of a group of molecules known as nucleic acids (Griffiths et al., 2009) which work alongside

nutrients

which

include

carbohydrates, lipids and proteins to enable the animal to function and do its day to day duties or activities (Griffiths et al., 2009) . RNA is very similar to that of DNA as this is also made up of a

Figure 7 The Four Nucleotide Subunits That Make up RNA

sequence or chain of nucleotides, of which comprises of a of a sugar known as ribose and phosphate groups. Attached to each sugar is one of four bases--adenine (A), uracil (U), cytosine (C), or guanine (G) (Creighton, 1997), as can be seen in Figure 5 The Four Nucleotide Subunits That Make up RNA. The formation of these nucleotides allows RNA to encode genetic material, this is done using messenger RNA (mRNA) (Creighton, 1997).

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

14

Comparisons of DNA and RNA Both DNA and RNA may share the same nucleic acids, they also differ in several ways, for example; 

DNA is double stranded, whereas RNA is single stranded, however they do share the same functions within the body.



DNA contains “deoxyribose, RNA contain “ribose” (Rastogi, 2007)



In DNA Adenine is compatible with Thymine, yet with RNA Adenine is compatible with Uracil

Figure 8 Comparison of DNA and RNA, Source (Ressata, 2013)

PROTEIN SYNTHESIS Protein synthesis is the process in whereby the body can produce its own proteins, using both DNA and RNA (Jurd, 2003). The process begins in the cell’s nucleus, where specific enzymes unwind using sections of DNA, which frees up the DNA and then a RNA copy can be made. This RNA molecule then moves from the nucleus to the cell cytoplasm, where the actual process of protein synthesis take place. The central SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

15

control system for protein synthesis can also be known as “The Central Dogma” Jurd, 2003), as can been seen in Figure 9 Process of Protein Synthesis, Source: (Brown, 2015)

Figure 9 Process of Protein Synthesis, Source: (Brown, 2015)

There are two basic steps to protein synthesis and these are: 

Transcription



Translation

Transcription The first step to transcription is the unwinding and unzipping of the DNA using the enzyme RNA polymerase, this breaks the hydrogen bonds and separates the DNA into single strands (Latchman, 1995). RNA polymerase then help the nucleotides to form a bond which makes a copy of the DNA and encodes (transmits) this in to mRNA. This process is stopped once it receives a stop signal (stop codon) from the organic basis (Latchman,

1995).

The

mRNA

is

then

transported from the cell nucleus and into the cytoplasm where this will inform the cell of its purpose Figure 10 Process of Transcription

SO112493

and

function

within

the

body

(Latchman, 1995).

HND ANIMAL MANAGEMENT: BIOLOGY

16

Translation Translation takes place on the ribosomes in the cytoplasm, or found on the rough Endoplasmic Reticulum (ER). The ribosomes are the sites of protein synthesis. The ribosomes are responsible for translating information in the mRNA into amino acids, this is done when the mRNA strand attaches to a ribosome (Karp, 2007, pp. 419 – 426). This is achieved with the help of tRNA, which are Special transfer molecules, these tRNA molecules then transport specific amino acids to the ribosome (Knight, 2008, pp. 196 – 199). All tRNA contain a three letter codes otherwise known as a “code on” which match up with mRNA within the ribosome, each mRNA codon codes for a specific amino acid and the anti-codons and codons Figure 11 How tRna obtains its three letter code "code on", Source: (BBC, 2011).

match

up

and

form

complementary base pairs and then peptide bonds form between the adjacent amino acids to form the polypeptide, which can be seen in Figure 10 How tRna obtains its three letter code "code on", which fold and form a protein (Mayer, 2003). mRNA can provide proteins with any genetic message and therefore determine its structure and its function, this stop once the ribosome identifies the stop code on and then the ribosome and the polypeptide release the new protein and its release into the body to be used by the required cell (Campbell, Reece and Reece, 2001, pp. 334 – 337).

After translation, the protein passes into the channels of the rough endoplasmic reticulum (ER) for transportation. The protein is then passed from the rough ER to the Golgi apparatus inside tiny fluid-filled sacs, called vesicles (BBC, 2011). The Golgi apparatus is a system of membranes, which are responsible for the modification, processing, and packaging of the proteins. The protein may have a carbohydrate added, to form a glycoprotein (BBC, 2011). The Golgi apparatus packages the protein in a secretory vesicle, which fuses with the cell membrane and releases the protein from the cell (Campbell, Reece and Reece, 2001, pp. 334 – 337).

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

17

Overview of Protein Synthesis

Figure 12 Overview of Protein Synthesis, Source: (Anonymous, 2012)

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

18

CHAPTER 3 TISSUE STRUCTURES

INTRODUCTION Within the body individual cells group together to form tissues and organs, a tissue is a collection of cells and their products which dominate the body, The cells in the body are arranged into four basic tissue types, these are identified as epithelial, connective, muscle and nerve tissues (Aspinall, Cappello, 2009). Each of these tissue types all have their own components: Cells- this is made up of the dominating cell and determines the tissue name i.e. muscle tissue contains mainly muscle tissue Intercellular products- these are fluid produced within the cells and lie between them Fluid- runs through the specialised channel within the structure of the tissue.

The function of epithelial tissue varies depending on its location within the body as can be seen in Figure 13 Epithelial Tissue and their Functions.

EPITHELIAL TISSUE Epithelial tissue covers both the internal and external surfaces of the body (Aspinall, Cappello, 2009), these include the body and organs such as the heart, blood vessels and lymph vessels.

The cells in epithelial tissue are very closely packed together and joined with little space between them. With its tightly packed structure, therefore acting as a type of barrier and providing a protective function and that is (VOER, 2015) For example, the skin is composed of a layer of epithelial tissue (epidermis) that is supported by a layer of connective tissue. It protects the internal structures of the body from damage and dehydration. Epithelial tissue helps protect the body by stopping microorganisms entering the body. The skin is the first step in defending the body against bacteria, viruses or any other microbe likely to cause infection or illness (Boyle, M et al, 2008).

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

19

Epithelial tissue have one main function and this is to absorb, secrete and excrete substances from the body. For example in the intestines, the tissue absorbs nutrients during digestion, epithelial tissue in the glands secretes hormones and epithelial tissue in the kidneys excretes waste as well as excreting perspiration from the sweat glands (VOER, 2015).

Epithelial tissue keeps the body systems separate, however they also have many other functions within the body. Epithelial cells also act as protection for the lungs by secreting mucus which traps inhaled dust and this function protects and sweeps it away from the lungs (Boyle, M et al, 2008).

There are known to be different types of epithelial tissue, this is very dependent on the size and shape of cells (Boyle, M, et al, 2008) and this will determine the number of cell layers they contain, please see below, Figure 13 Different Variations of Epithelial.Tissues.

Figure 13 Different Variations of Epithelial Tissues, Source: (VOER, 2015)

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

20

Simple Squamous – which allows materials to pass through cells by diffusions and filtration and is also responsible for secreting a lubricating substance. Simple Squamous epithelial tissue can be located in the air sacs in the lungs, the lining of the heart, with blood vessels and also the lymphatic vessels Simple Cuboidal- is responsible for secreting substances and absorption. These tissues can be found in the ducts, in the glands and also the kidney tubules Simple Columnar- is responsible for absorbing nutrients, however it is also able to secret mucus and enzymes. Ciliated tissues can be found in the bronchi, uterine and uterus tubes, where as smooth tissue can be found in the digestive tract and the bladder Pseudo stratified Columnar- secretes mucus, and ciliated tissue are responsible for the movement of this mucus.

Stratified Squamous- protects against damages such as abrasions and these tissues can be located within the lining of the oesophagus, mouth and vagina.

Striated Cuboidal – is simply a protective tissue and protects cells such as glands, salivary glands and also the mammary glands Striated Columnar- is designed to secrete and protect and is commonly found within the male urethra and the ducts of some glands.

Transitional- is responsible for allowing the urinary organs to expand and stretch, transitional tissues line the bladder, urethra and the uretors

CONNECTIVE TISSUE Connective tissue is found in different forms such as blood, cartilage and bone. The main function of connective tissue is to bind tissues and organs together and holds them in place, which will in turn provide support to parts of the body as well as being responsible for carrying nutrients to the tissues within the body and removing waste materials (Aspinall V, Cappello M, 2009). Connective tissue consists of cells encased in an extracellular matrix or ground substance (Boyle, M, et al, 2008). It is the properties within this ground substance which determines they types of connective

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

21

tissue (Boyle, M, et al, 2008). There are several different types (please refer for figure 14 below)

Figure 14 Connective Tissues Found Within An Animals Body Source: (Anonymous, 2014)

These different types of connective tissue all have different structures and functions within the body; Blood is a specialised connective tissue that circulates through the blood vessels to carry nutrients and oxygen to the cells, and waste products to the organs of excretion.

It consists of a number of different types of blood cell within the ground substance, for example the plasm (Campbell, M, et al, 2008) Haemopoietic Tissue is a jelly like tissue which forms the bone marrow within long bones and is responsible for the formation of the blood cells within the body (Cohen, 2000) Areolar Tissue (loose connective tissue) is distributed all over the body, i.e. beneath the skin and around the blood vessels and nerves (Boyle, M, et al, 2008). The ground substance contains two types of protein fibres known as collagen and elastic fibres.

Collagen fibres are of a high strength and elastic fibres enable the tissue to stretch and return to its former shape (Aspinall V, Cappello M, 2009).

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

22

Adipose Tissue is very similar to Areolar Tissue however its matrix contains mainly fat filled cells. These fat cells act as an energy reserve and also insulates the body to reduce heat loss (Campbell, M, et al, 2008).

Dense Connective Tissue is made up of tightly packed collagen fibre bundles with very few cells in-between. This formation of these fibres determines which part of the body this tissue is to connect too, for example; Parallel arrangement- known as regular fibrous connective tissue.eg tendons (long bands of strong fibrous tissue linking muscles to bone) and ligaments (link bone to bone) (Aspinall, Cappello, 2009) Irregular interwoven fibres- this is seen in the surface of the skin of in the capsule of the joints Cartilage is a specialised connective tissue which is rigid but flexible, resilient and able to withhold incredible amounts of weight and is made up of cells known as chondrocytes (Aspinall, 2011) and fibres within a gel like ground substance. Cartilage had no blood supply however its nutrition is solely supplied via the perichondrium within the cell (Alberts, B, et al, 2002) Bones forms the skeleton of the animal and is also responsible for protecting and supporting the main organs within the body as well as aiding in locomotion. It is also a living tissue which has properties which enable it to remodel and repair itself if damaged (Aspinall, Cappello, 2009). The bone is made up of an extracellular matrix of ground substance that’s contains two types of fibres, these are osteonectin an collagen fibres, and together these form osteoid, which becomes deposited as bone tissue become calcified, the calcification of bone provides it with rigidity and hardness (Campbell, M, et al, 2008).

MUSCLE TISSUE There are 3 types of muscle tissue within the body, these muscles are classified as smooth, cardiac, and skeletal. The voluntary contraction of skeletal muscles allows movement of the body, for example movement of the eyes. Cardiac and smooth muscles occurs without conscious thought, as an automatic movement, for example

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

23

the cardiac muscles in the heart causes it to pump blood, and also the intestines pushed food through the digestive system and out as waste and this is known as an involuntary contraction

The functions of muscles is to allow for support, movement, protection and storage.

This is done by the sensory receptors which are situated within the muscles, and they can indicate the length and tensions of the muscle, therefore sending a message through the body to the nervous system to inform them of the body position allowing posture to be maintained.

Muscle tissue has four main properties: 1. Excitability (ability to respond to stimuli), 2. Contractibility (is ability to contract), 3. Extensibility (the ability of a muscle to be stretched without tearing) 4.

Elasticity (the ability to return to its normal shape).

(Campbell, M, et al, 2008)

Within the body, there are three main muscle groups, which all have individual tasks which enable the body to function in the correct way, and they are as follows:

Smooth Muscle The smooth muscle Cells are non –striated and elongated with tapered ends and are surrounded by small amounts of connective tissue that bind the cells into sheets or layers and has on central nuclei similar to that of cardiac muscle tissue. Smooth muscle is found within the hollow organs, normally found within walls of the intestines, bladder and uterus. This muscle regulates the flow of blood in the arteries, helps with the removal of feces and urine and regulates airflow through the lungs (Aspinall V, Cappello M, 2009).

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

24

Cardiac Muscle Is a specialized muscle that only works within the heart, is very similar to smooth muscle except the fibers are branched and interconnected (Aspinall V, Cappello M, 2009). This muscle is striated, and it’s this striated muscle which branch to create a network of fibers which are known as intercalated disks (Alberts, B, et al, 2002), these enable nerve impulses to be conveyed extremely quickly which in turn produces a fast response to the changing needs of the body.

Cardiac muscle is cylindrical in shape and has a number of nuclei and Its main function it to continuously beat to sustain and maintain life, and never gets tired, allowing it to keep functioning and informing body of other requirements it will require i.e. more nutrients and oxygen when exercising to allow heart to pump blood faster to muscles within the body (Alberts, B, et al, 2002)

Skeletal Muscle These muscles cover our internal skeletal and provides us with a shape and also enable movement, this is achieve via voluntary or conscious control.

Skeletal muscles are long and cylindrical and lie parallel to one another, however each individual muscle fiber is made up of bundles of microfilaments known as myofibrils these consist of actin (thin filaments) and myosin (thick filaments) and it’s this arrangement that gives them their striated appearance (Boyle, M, et al, 2008), please refer to figure 2 Diagram of Muscle Breakdown.

Muscle fibers group together in bundles by connective tissue and form one larger muscle, the muscle is surrounded by muscle sheath which enable the muscle to connect to bone (Aspinall V, Cappello M, 2009). These muscles are connected to the bone by tendons and ligaments which allow the muscle to contract to allow for movement for example when the dog walks or wags its tail.

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

25

The muscles within the body are made up of several muscle fibres which are made up of compact cells called Myofibrils which contain Actin and Myosin filaments which are stored within the sarcomere (please refer to figure 2 below). These lie parallel and intercalated with one another. The process of muscle contraction is known as The Sliding Filament Theory.

Figure 15 Diagram of Muscle Breakdown SOURCE: (Thomson Learning, 2002)

This process is as follows: 1. The myosin filaments move along the actin filament, small protein heads on the myosin filament attach and bind together to form a cross bridge producing energy known as adenosine diphosphate (ADP)

2. The myosin head then changes shape and pulls the actin filament towards the center and releases ADP, which shortens the sarcomere.

3. The new energy known as adenosine triphosphate (ATP) then attaches to the myosin head which then releases and breaks the cross bridge

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

26

4. The un-used ATP energy then begins to broken down into ADP and a single molecule of phosphate (P), so it becomes ADP + P (again) for the process to repeat its self.

Figure 16 Process of muscle contraction Source: (Cummings, 2001)

This process is repeated and causing the sarcomere to shorten, which in turn Allows the muscle to contract and the limbs to move in different directions using Several methods of movement.

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

27

NERVE TISSUE Nerve tissue is responsible for transmitting nerve impulses from one area of the body to another and also coordinates the animal’s response. This is achieved by the neuron which is made up of a nucleus, Dendron’s which are short term processors, which are responsible for carrying information towards the cell body, and axons which main function is to transmit messages away from the cell body and towards its intended target or body part (Boyle, M, et al, 2008). These nerve impulses which are transferred via the Figure 17 Structure of Nerve Tissue, Source: (Coniel, 2012)

Dendron’s and the axons are transported by

button like structures known as synapse. This is done via a process known as neuromuscular junctions, this is when the axon terminates and transfers into muscle fibre, which in turn stimulates nerve impulses and instructs the muscles to contract and aid in movement (Boyle, M, et al, 2008).

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

28

CHAPTER 4 ANIMAL ORGANS INTRODUCTION An organ is a collection of specialised tissues which form a structure within the animal’s body in order to perform a specific task or duty, i.e. Heart, lungs and blood vessels. These organs make up the cardiovascular system, please refer to Chapter 5: Organ Systems for more in formation Different tissue make up organs within the body, the three main organs are the heart, blood vessels and lungs.

THE HEART The heart is a muscle which is made up of cardiac Tissue, which under a microscope is striated. The heart of mammals has four chambers consisting of right atrium, right ventricle,

left

atrium,

left

ventricle

(anonymous,2013), please refer to Figure 18 Anatomy of The Heart, however this is species dependant,

please

refer

to

Figure

22

Comparison of Hearts With in a Number of Different Species Figure 18 Anatomy of The Heart , Source:(Shutterstock, 2015)

Please refer to Chapter 5: Organs -Circulatory system for further information on how the heart

works.

This muscle is reliable for pumping blood to all part of the body, which is contained within the pericardial sac which supports the heart and contains fluid as this is need to lubricate the heart to enable it to beat, the heart is situated between the lungs within the thoracic cavity (Aspinall, 2006).

The heart is able to function due to blood vessels which are a network of hollow tubes which transport blood, these are known as arteries, capillaries and veins;

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

29

Arteries which carry oxygenated blood away from the heart, but the pulmonary artery carries deoxygenated blood to the lungs. They are composed of three layers of tissue, and the inside layer is coated with special anti-clotting factors which keep the blood from clogging (Aspinall,2001). The middle layer contains muscle and elastic fibers, and the outside is comprised of connective tissue and elastic fibers, please refer to.

Figure 19 Structure Of An Atery, Source (Anonymous, 2013)

The elasticity of an artery allows it to flex and accommodate blood being pumped into it with a lot of force (MRCVS, 2009).

Capillaries are small and have a thin wall which allows nutrients, and they are made of epithelial cells. Capillaries allow water and oxygen to diffuse from the blood into the tissue, this is where the gaseous exchange takes place and the waste products such as carbon dioxide diffuse from tissue into blood (Reece, 2009).

Figure 20 Structure of Capillaries within The Body, Source: (Anonymous, 2013)

Veins are the blood vessels which return blood to the heart and rest of the body. Veins have thinner walls and are larger in size which encourage the blood to flow back to the heart. Veins have one-way valves incorporated into them, which prevent blood from flowing backwards away from the heart (Reece, 2009).

Despite arteries, capillaries and veins al having their very own functions and individual structures within the body, they do share similarities, as they are all responsible share an epithelial layer, transport blood,

Figure 21 Structure of a Vein. Source: (Anonymous, 2013)

oxygen and other materials around the body, are found in different organs within the body and all three make up part of the circulatory system (Turnhill, 2011).

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

30

The heart is a very complex muscle and is continuously working. The heart allows the transportation of oxygen and nutrients to correct parts of the body via the blood.

However this does vary on the type of animal, each species has a slightly different heart structure, as can be seen below in Figure 22 Comparison of Hearts With in a Number of Different Species.

Figure 22 Comparison of Hearts with in a Number of Different Species, Source: (Maaske, 2012)

The main reason for the variations in the structure of the heart is for the use of thermoregulation. Warm-blooded animals require the more-efficient system of four chambers that has the oxygenated blood completely separated from the deoxygenated blood. Whereas other animals such as snakes and reptiles rely mainly on their environment to regulate their temperature to ensure survival. For example, the heart within in a fish is long, and folded and consists of an atrium and a ventricle, therefore being known as a single circulatory system (MRCVS et al., 2009a, pp. 184 – 185). The reason for this is blood passes through the heart once per circulation, to ensure a permanent supply of oxygen. Amphibians however have a the single atrium that is divided into two separate chambers., which is a major respiratory organ in amphibians, please refer to Figure 22 Comparison of Hearts with in a Number of Different Species.

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

31

Reptiles however have a heart consists of 3 chambers rather than four, they have both a left and a right atrium but only one ventricle, which is divided into three sub chambers which receive blood from both the left and right atria. The mammalian heart is very similar to that of reptiles, its conical in shape and is

Figure 23 Structure of The mammalian Heart, Source: (Turnhill, 2011)

responsible for pumping blood through the blood vessels and around the body, the heart is enclosed in a double layered serous sac known as the pericardium and lies slightly to the left in the chest cavity (Stewart, 1991, pp. 148 – 150).

The mammalian heart is the more complex systems and has four chambers consisting of right atrium, right ventricle, left atrium, left ventricle, which are on either side of the heart . The atrium are thin walled and the ventricle are made up of thicker layers of muscle known as myocardium. (MRCVS et al., 2009b, pp. 81 – 84) The ventricles are the main pumping chambers with the right ventricle pumping directly to the lungs (the pulmonary Circulation), however the left ventricle is responsible for pumping and controlling the amount of blood around the body (Stewart, 1991, pp. 148 – 150). This is known as a double circulatory system, please see chapter 5: Respiratory System for further information

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

32

THE LUNGS The lungs in mammals such as a cat are made up of a double layer connective tissue known as mediastinum. Each lung is consists of air passages, blood vessels that surround the connective tissue, which are all contained within a membrane called Pulmonary Pleura (Aspinall V, Cappello M, 2009), this is made up of Simple squamous epithelial cells which are thin and flat. The main function of Simple squamous epithelial cells are for the purpose of filtration and diffusion. Due to their simple and thin construct, they allow

Figure 24 Structure of Lungs Within a feline Source: (Kuehn, 2011)

for easy movement of small molecules whether this be across the membrane, and through the cell. Simple squamous epithelium is found in several locations where rapid diffusion or filtration take place, this may include the kidney, alveoli in the lungs and within cavities and blood vessels within the body (Meyer, 1978).

Each lung contains lobes which are known as bronchi, the left has 3, whereas the right has 4. Bronchi transports oxygen to the lungs, from each bronchi are small extensions known as bronchioles, which have small grape liked bunches of cells known as Alveoli which are also responsible for providing oxygen as well as removing carbon from the lungs . For more detailed information on how the lungs function please see Chapter 5, Organ Systems: The Respiratory System Lungs play a vital role within the body by providing oxygen to capillaries so they can oxygenate blood (Anonymous, 2015) Some species such as fish have lungs which are used for gaseous exchange but over time their bodies have evolved and adapted and therefore now use a different process, which can be seen below;

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

33

Figure 25 Gas Exchange Organs Source: (Associates, 2015)

Fish Gills are responsible the gas exchange in fish. These organs, located on the sides of the head, are made up of gill filaments, feathery structures that provide a large surface for gas exchange. The filaments are arranged in rows in the gill arches, and each filament has lamellae, discs that contain capillaries. Blood enters and leaves the gills through

these

small

blood vessels (Newby, 2013). Although gills are restricted

to

a

small

section of the body, the immense

respiratory

surface created by the gill filaments provides the whole animal with

Figure 26 How Gas Exchange is achieved In a Fish, Source: (Newby, 2013)

an efficient gas exchange. The surrounding water keeps the gills wet. A flap, the operculum, covers and protects the gills of bony fish (Newby, 2013) .Amphibians Amphibians either gills or an internal lung structure which are small air sacs, this is dependent on the environment they live in. Frogs and other amphibians have permeable skin which is used for the purpose of gaseous exchange during periods of low oxygen requirement for example during hibernation (Maina,2005). This is achieved SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

34

as they can take in oxygen through their skin as long as it is moist. This can restrict them to living in moist habitats. It can also make them susceptible to losing a lot of water from their bodies. Other animals such as salamanders increase the skins surface area, and this is done via the folds in the skin or the hairs on the skin surface which in turn help reduce oxygen demands or metabolic rates to encourage gaseous exchange (Girling, 2003, pp. 263 – 265).

Reptiles Unlike amphibian, retiles cannot use their skin for gaseous exchange and are solely reliant on their lungs similar to that of mammals, and therefore their lungs are more efficient than other species as they have adapted to have a much larger surface area to allow for this gas exchange to take place (Hillman, Withers and Drewes, 2008b).

The lungs work via the inflation and deflation of the ribcage however some species of reptiles such as the alligator may have a more complex system for gas exchange, they have a muscular diaphragm that is slightly different to that of a mammalian diaphragm (Hillman, Withers and Drewes, 2008b).

The difference is that the muscles for the crocodilian diaphragm pull the pubis (part of the pelvis) back, which brings the liver down, thus freeing space for the lungs to expand. This type of diaphragmatic setup has been referred to as the "hepatic piston."

The airways bronchia form a number of double tubular chambers within each lung. On inhalation and exhalation air moves through the airways in the same direction, thus creating an unidirectional airflow through the lungs (Maina, 2005).

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

35

CHAPTER 5 ORGAN SYSTEMS INTRODUCTION Body systems are a collection or organs and tissues which are related by their function and work together to maintain equilibrium within the body e.g. the respiratory, digestive and cardiovascular system (Aspinall V, Cappello M, 2009) In this chapter you will learn about the structure, function and importance of the respiratory and the Circulatory system Organ systems are groups of organs that carry out a particular function. The animal body has several organ systems, which all play a vital role in maintaining health and survival of all animal species, these organ systems may not work alone but in conjunction with one another to carry out different functions, the organ systems include; 

The nervous system



The respiratory system



The Circulatory system



The reproductive system



The digestive system

THE RESPIRATORY SYSTEM The respiratory system is essential for the animals survival as all animals require oxygen within their bodies to carry out chemical processes, oxygen is essential for the cell to obtain energy from raw materials derived from food particles, this requires a process known as oxidation of glucose to form energy (ATP) (Schmidt-Nielsen and Schmidt-Nielsen, 1997).The main function of the respiratory system is to break down and transfer gases needed i.e. oxygen to enable to the heart to beat, and to remove waste products such as carbon dioxide (Boyle, M, et al, 2008). The respiratory system in mammal consists of two separate sections; these are known as the upper and a lower respiratory tract.

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

36

The upper respiratory Tract consists of: Mouth (oral cavity) which is lined with ciliated tissue. This is where oxygen warms/cools air as it enters body. The main function of the mouth is to trap and remove dirt, stopping foreign bodies/ bacteria from entering the body (Slatter, 2003) Pharynx (throat) is made up of cartilage

Figure 27 Components Which Make Up the Upper Respiratory Tract Source: (Smith, 2013)

which are connected by ligaments. The Pharynx connects the nose and larynx together, Tonsils lie within the pharynx which are used to fight disease and infection (Slatter, 2003) Larynx (voice box) Contains an epiglottis which is a small valve which closes once it detects food which stops food going into the windpipe and preventing choking (Slatter, 2003). The main duty of the Larynx is to provide vocalization i.e. barking or growling in dogs, or purring or hissing in cats (Aspinall, 2001) Trachea (windpipe) Is made up rings of cartilage in a C shape which forms a strong rigid structure which stops it from collapsing and is responsible for carrying oxygen from the throat to the lungs

The Lower Respiratory Tract contains; Bronchi: These are lobes which sit within the lungs and are responsible for transporting oxygen within the lungs Bronchiole are an extension from the bronchi Alveoli: Look like a bunch of grapes which attach to ends of bronchioles. Their main function is to transport the oxygen to the lungs as

Figure 28 Components which Make Up The Lower Respiratory Tract Source: (Kuehn, 2011)

well as removing carbon dioxide from the body.

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

37

Respiration is where the body breaks down oxygen to be used within the body to enable breathing. This is done by a process known as diffusion, this means gases (oxygen and carbon dioxide) moves from an area of high concentration to an area of low concentration, is broken down, then the oxygen is then absorbed into the bloodstream this then enables to oxygenated blood to be transferred to the lungs and heart which is needed to aid in the continuous beating process and the carbon dioxide is removed from the body (Church, Pond and Pond, 1995). This will therefore allow internal organs to work correctly and to full capacity when required, this may be when dog is running or exercising Respiration is achieved when air is inhaled via the nose or mouth it then passes down the pharynx and the larynx, and travels down the trachea. Then it enters the lungs traveling and entering into the bronchi where oxygen is transported further down into the bronchioles (Boyle, M, et al, 2008). Oxygen then enters the alveoli, the oxygen is then broken down using diffusions and the re-oxygenated blood is then transferred via the capillaries to the lungs and transported to the hearts and then the carbon dioxide is expelled from the body(Aspinall V, Cappello M, 2009.

This process would not be able to occur if it wasn’t for the diaphragm, this is a complex process as explained below in Figure 11 “Respiration Process In a Human Body”.

Figure 29 Respiration Process In a Human Body Source: (http://www.inshapellc.com, 2007

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

38

INHALATION: 1.

The intercostal muscles contract, expanding the ribcage.

2.

Diaphragm contracts, pulling downwards to increase the volume of the chest.

3.

Pressure inside the chest is lowered and air is sucked into the lungs.

EXHALATION: 1.

The intercostal muscles relax, the ribcage drops inwards and downwards

2.

The diaphragm relaxes, moving back upwards, decreasing the volume of the

chest.

3.

Pressure inside the chest increases and air is forced out.

(BBC, 2013)

The respiratory system also acts as a cooling system for some animals such as the dog, because unlike humans they cannot sweat through their skin to get rid of excess water, therefore they have to use their tongues to pant hard which allows air to be passed from the lungs which is then cooled down (Cherniack and Widdicombe, 1985), therefore allowing the moisture within the body to evaporate, in turn cooling the dog down.

Fish Fish get their oxygen from water. As a fish swims, it gulps up water. The water which has oxygen goes through an opening in the fish’s throat that leads to the gills. Gills have many blood vessels within them (Aspinall, 2011). Oxygen moves from the water to the blood as the water flows over the gills. The blood vessels gather and store the oxygen that travels over the gills. At the same time, carbon dioxide moves out of the blood and into the water. Now, the water flows out of the slits beneath the gills. These gills are located under the operculum (Aspinall, 2011) , for further information on this process please see Chapter 4: Animal Organs.

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

39

Amphibians Both the lungs and the skin serve as respiratory organs in amphibians. The skin of these animals is highly vascularized and moist, with moisture maintained via secretion of mucus from specialized cells. While the lungs are of primary importance to breathing control, the skin's unique properties aid rapid gas exchange when amphibians are submerged in oxygen-rich water (Aspinall, 2011).

Reptiles Respiration differs in each main reptile group, all reptiles breathe air through the use of lungs. Despite lacking a diaphragm muscle, reptiles have a diaphragm-type respiratory system and the act of breathing is accomplished by the reptile moving its throat or rib cage (Hargens and Wood, 1991, pp. 151 – 159). Air flow through the lungs in both directions (bidirectional), air travels into the lungs through the bronchial tubes to tiny air sacs, or alveoli. The exchange of oxygen and carbon dioxide takes place within the alveoli and the used air is then exhaled out of the lungs through the same route which it entered (Hargens and Wood, 1991, pp. 151 – 159). However due to lack of diaphragm, reptiles lack the cough reflex and therefore more susceptible to respiratory infections that can be severe and even fatal (MRCVS et al., 2009c, pp. 177 – 178) The act of breathing can be quite a task for some reptiles due to their body and lung structure. The lungs of lizards and snakes are ventilated by the skeletal muscle within the body of the snake, also known as axial muscles. These same muscles are used for locomotion so most lizards and snakes are forced to hold their breath during locomotion (Hargens and Wood, 1991, pp. 151 – 159). Some lizards work around this by completely filling their lungs by pumping water through their mouth and over their gills. This method is known as buccal pumping which allows them to remain aerobically active for a longer period of time (Hargens and Wood, 1991, pp. 151 – 159).

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

40

THE CIRCULATORY SYSTEM The circulatory system consists of the heart, vein, capillaries, arteries please refer to Chapter 4 Animal Organs, lymph vessels and lymph glands which work together to supply the body tissue with nourishments and dispose of waste products.

The Circulatory system is responsible for distributing nutrients such as oxygen needed by the heart and lungs, getting rid of waste products such as vitamins, minerals via the kidneys (Aspinall V, Cappello M, 2009).

The main function of the circulatory system is to: 

Transportation of oxygen and nutrients



Regulated body temperature



Prevent excessive bleeding



Prevent infection



Gaseous exchange

The circulatory system will use different organs within the body to help deliver nutrient around the body, this is done mainly via the blood vessels, capillaries and veins within the hearts, please refer Figure 10 “Circulatory system of the heart”, below; 1.

Blood low in oxygen/ high in carbon

dioxide travels from the body through the vena cava 2.

Into the right atrium

3.

Through the right

atrioventricular

valve in the right ventricle 4.

Forced to the lungs through the

pulmonary arteries, where the CO, in the blood is replaced by oxygen Figure 30 Circulatory system of the heart (Drs foster smith, 2013)

SO112493

5.

Back to the heart via the pulmonary

veins

HND ANIMAL MANAGEMENT: BIOLOGY

41

6. Into the left ventricle 7. Through the left atrioventricular valve, into the left ventricle 8. Into the aorta 9. Back Into the body

The circulatory systems is devised into two parts: Pulmonary circulation- de-oxygenated blood is pumped to the heart and lungs where it is oxygenated and returns to the heart and lungs (MRCVS et al., 2009, pp. 84 – 86).

Systemic circulation oxygenated blood from heart and all other body parts and unoxygenated blood is returned to heart (MRCVS et al., 2009, pp. 84 – 86), which can be seen below in Figure 8 “Blood circulation with a dog’s body”

REDOxygenated blood BLUE deoxygenated blood

Figure 31 Blood Circulation Within A dogs Body, Source: (BBC, 2012)

However the circulatory systems differ within different species, and the reason for this specific animals have different numbers of heart chambers due to their living environments and therefore have varied requirements, evolution has allowed these adaptions over time and this will determine how their bodies process oxygen and nutrients within the body, please refer to Chapter 4 Animal Organs: The Heart.

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

42

Fish Water

containing

dissolved

oxygen enters the fish's mouth, and the animal moves its jaws and operculum in such a way as to pump the incoming water through the gills. As water passes over the gill filaments, blood inside the capillaries picks up the dissolved oxygen (Fernandes, Rantin and Glass, 2007). Since the blood in the

Figure 32 Circulatory system of a Fish, Source (Swan, 2014)

capillaries flows in a direction opposite to the flow of water around the gill filaments, there is a good opportunity for absorption. The circulatory system then transports the oxygen to all body tissues and picks up carbon dioxide, however other waste products can also be collected and excreted via the kidneys, the blood then flows to the atrium of the heart in the veins which is removed from the body through the gills. After the water flows through the gills, it exits the body behind the fish's operculum (Fernandes, Rantin and Glass, 2007) , please refer to Figure 32 Circulatory system of a Fish

Reptiles and Amphibians Both species have a very similar circulatory system, and may consist of having lungs as well as using their skin for gaseous exchange, therefore this means the body has two separate circulatory systems (Linzey, 2001), for example in amphibians, Oxygen-rich blood from the lungs enters one atrium, and oxygen-poor blood enters the other. Oxygen-rich blood is pumped

SO112493

Figure 14 Blood circulation of Amphibians, Source: (Freeman, 2009)

HND ANIMAL MANAGEMENT: BIOLOGY

43

from one ventricle to the body tissues, while oxygen-poor blood is sent from the lungs to the skin, in order for gas exchange to occur; this is called pulmocutaneous circulation (Reece, 2010).

Where as in reptiles the circulatory system always ensures deoxygenated blood from the right atrium is them pumped to the pulmonary artery but the oxygenated blood returning from the lungs to the ventricle will pass via the aortic arches or travel to the Pulmonary circulation (MRCVS et al., 2009a, pp. 175 – 176), please refer to Figure 22 Comparison of Hearts With in a Number of Different Species.

Reptiles have a complex circulatory system and this is due to the renal portal system which is responsible for transporting blood from the hind limbs and tail directly to the kidneys (Girling, 2003) and this can be problematic if the animal become ill and medication id administered in to lower half of the body, as some of the drug will be immediately absorbed and excreted via the urine before it has been able to travel through the circulatory system and been able to take effect within the body (Girling, 2003). This variation in blood flow allows reptiles more effective thermoregulation and longer diving times for aquatic species, but has not been shown to be a fitness advantage (Hicks, 2002).

Mammals and Birds Mammals have a double circulatory system. This process involves the movement of deoxygenated blood returning from around the body is always carried to the right side of the heart by the main veins which are the Cranial Vena Cava and Caudal Vena Cava (Frandson, Wilke and Fails, 2009), the blood enter the right atrium via the right atrioventricular valve, and now the blood is within the pulmonary circulation where it is carried to the lungs, along the way it picks up oxygen and becomes oxygenated.

From here the oxygenated blood is carried via the pulmonary veins back to the left side of the heart, the blood enter the left atrium, which contracts when full and forces the blood through the left atrioventricular valve into the left ventricle. (Frandson, Wilke and Fails, 2009) When the left ventricle is full it pumps the into the main artery of the body the aorta via the aortic valve, and this ensure the blood is within the systematic circulation and travels around the body via the arteries, oxygen is transported to the tissues and carbon dioxide is removed from the tissues and expelled from the body SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

44

(MRCVS et al., 2009b, pp. 81 – 84), please refer to Figure 22 Comparison of Hearts with in a Number of Different Species

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

45

CHAPTER 6

Animal Physiology and Homeostatic Control The endocrine system (also known as hormonal) is one of the major control systems within the body, alongside the nervous system (Brown, 2001, pp. 197 – 199). The nervous system brings about immediate responses through the use of neurons, but the endocrine system is slower acting and regulates processes that occur over days or even months (Squires, 2003). Both these systems have different ways of transmitting messages around the body as can be seen below in fig 32: Chemical Communication.

Endocrine systems control the body through the use of hormones.

Hormones

are

chemical

messengers produced by ductless glands in one part of the body which travel through the bloodstream and exert their influence in another part of the body (Aspinall, 2006, pp. 71 – 73, examples of hormones include insulin, which is important in the development

of

diabetes,

and

estrogen and progesterone, which are

involved

in

the

female

reproductive cycle (Aspinall, 2006, pp. 71 – 73). These are secreted by Figure 32 Chemical Communication

the endocrine glands, please refer to

Figure 36: The Major Endocrine Glands in A Horse.

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

46

Hormones are secreted into the bloodstream and regulate whole body processes like growth, reproduction, complex behaviours including courtship and migration.

Hormones also influence the metabolism of their target cells by binding to receptor proteins within the cell or on the surface of the cell, please refer to Figure 34:Neuron Structure .

The image (fig 32: Chemical Communication) opposite shows how the different types of systems send messages to cells and tissues.

The endocrine system is responsible for releasing chemical messengers (neurotransmitters) called “hormones”, Hormones are transported via the blood which act as a transport system which help the endocrine glands in one part of the organisms which can influence the activity of cells in another part (Reece, 2009). This enables the animal to have two communication systems, a nervous system and a hormonal or endocrine system, which can be seen

Figure 33 Endocrine Transport System

in Figure 33: Transportation System for Hormones.

The nervous system is made up of nerve cells which are known as neurons, these consist of a cell body and have two extensions which are known as Dendrites, which transmit impulses from the tip the rest or the nerve and Axons which are bundles of tiny nerve ending which transmit impulses to another neutron or toward the muscle, tissue or cell (receptor site) that carried out the bodies responses, which can be seen below in Figure 34: Neuron Structure (Cajal, Pasik, and Pasik, 2002, pp. 1 – 09) Nerve communication is usually rapid and in short duration, however hormonal responses are much slower in onset but have a longer lasting duration and involved wide scattered cells. Neurotransmitters (messenger molecules) work over a short distance, compared to hormones which act over longer periods (Cajal, Pasik, and Pasik, 2002, pp. 1 – 09). The nervous system is best suited for co-ordinating activities which require rapid and continuous adjustments such as breathing and running.

Whereas the endocrine system is best suited to long term regulation for example the control of reproductive cycles or the maintenance of blood glucose levels .

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

47

Figure 34: Neuron Structure Source: Educare, 2012

The nerve and endocrine systems are not entirely separate modes of molecular communication, they rely on one another, since much of the nervous system is controlled by the endocrine system there are similarities between the two systems, for example, some nerves release hormones and chemical messengers can act as messengers and hormones (Squires, 2003).

Intercellular communication in both systems are slightly different as came been seen below in Figure 35: How signals are Distributed Within the Endocrine and Nervous System. This is essential as it enable messenger molecules and specific recognition molecules which are part of the target cell or tissue (Cajal, Pasik, and Pasik, 2002, pp.

1 – 09) These recognition sites or molecules are known a receptors and provide a vital role within both systems as they communicate and allow messages to be sent to the target cells or tissues ensuring they respond to specific hormones or neurons which in turn has an effect on the body or interact and work alongside other hormones to create a network which acts to maintain the balance within the body and keep it at a state of equilibrium.

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

48

Figure 35: How signals are Distributed within the Endocrine and Nervous System, Source: (Reece et al., 2010)

The endocrine system consists of a variety of endocrine glands which are made known to be ductless, and are made up of cells of epithelial tissue and supported by connective tissue which must be rich in blood and lymphatic capillaries, this allows for rapid absorption into the circulatory system (MRCVS et al., 2009a, pp. 71 – 77) .

All endocrine glands have different functions in regards the hormones they produce, these are as follows: The hypothalamus, which is not a gland but a nerve centre, also plays a major role in the synthesis of hormonal factors. The hypothalamus is composed of several nuclei that control the nervous system and are responsible for regulating hunger, thirst, body temperature and sleep (Rudkin, 2006). The hypothalamus also influences sexual behaviour and controls the emotions of anger and fear. Closely linked to the pituitary gland, it acts as a coordinator between the nervous and endocrine systems

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

49

The Pituitary Gland- is located near the centre and bottom of the brain. It is responsible for producing a varied number of critical hormones that control many parts of

the body,

including several other

endocrine glands. Due to this, it is referred to as the “master gland.”.

The adrenal glands can be found in front of the kidneys. The adrenal gland has 2 parts—the cortex and the medulla.

The adrenal cortex consists of 3 layers, which all produces a different set of steroid hormones; The outer layer produces the mineralocorticoids, which help to control the balance of sodium and potassium salts within the body.

The middle layer produces glucocorticoids, which are involved in metabolizing nutrients as well as aiding the reduction of

Figure 36: The Major Endocrine Glands in A Horse, Source: (Greco, 2001)

inflammation.

The inner layer is responsible for the production of sex hormones such as estrogen and progesterone. The adrenal medulla plays an important role in response to stress or low blood sugar (glucose). The messengers within the body release information which stimulates the release of epinephrine (sometimes called adrenaline) and norepinephrine, both of which are responsible for increasing heart rate, blood pressure, and blood glucose, and slow down digestion (MRCVS et al., 2009a, pp. 71 – 77) .

The pancreas is made up of several types of cells and can be located in the loop of the duodenum in the adnominal cavity, the individual cells have specific functions involved in the production of hormones and digestive enzymes. The pancreas has an exocrine part and an endocrine part, and therefore described as a mixed gland. The exocrine part secretes digestive substances which enter the duodenum via the pancreatic duct. The endocrine secretion are produced by tissues within the exocrine tissue these are known as the islets of Langerhans.

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

50

The islets of Langerhans in the pancreas consist of 3 types of cells, each of which secrete a different hormone (Porter, 2009). Most of the cells, which are called beta cells, produce insulin. Insulin affects, either directly or indirectly, the function of every organ in the body, particularly the liver, fat cells, and muscle. In general, insulin increases the transfer of glucose and other compounds into body cells. It also decreases the rate of fat, protein, and carbohydrate breakdown.

The islets of Langerhans is also responsible for producing the hormones glucagon and somatostatin. Insulin and glucagon work together to keep the concentration of glucose in the blood (Porter, 2009) and other body fluids within a relatively narrow range. Glucagon controls glucose release from the liver, and insulin controls glucose transport into numerous body tissues (Sardesai, 2011, pp. 417 – 418).

The thyroid gland is a 2-lobed gland which can be found in the neck, within the first few rings of the trachea. It produces the iodine-containing hormones, Tri-iodothyronine (T3) and Thyroxine (T4), which can be responsible for regulating metabolic rate and growth, and regulating the speed of the bodies processes (Dodds and Laverdure, 2012). Thyroid hormones work along with other hormones, such as growth hormone and insulin, to build tissues. However, when they are secreted in excess, they can contribute to breakdown of proteins and tissues (MRCVS et al., 2009a, pp. 71 – 77).

The parathyroid glands can be found down the sides of the neck of the horse, and are responsible for helping to regulate the body's levels of calcium and phosphorus in the blood (Budras, Sack and Rock, 2004). The parathyroid glands is also essential for the way the body processes calcium and phosphate, the function of vitamin D, and the formation of bone are all tied together into a system that involves 2 other hormones known as parathyroid hormone and calcitonin (Kahn and Line, 2007) and these are secreted by the parathyroid glands.

Secretion of hormones occurs in response to a specific stimuli, this may include: 

Nerve impulses- a key example of this is adrenaline, which is released from the adrenal medulla in response to nerve impulses from the sympathetic nervous system

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

51



A stimulating or releasing hormone- examples include TSH (thyroid stimulating hormone) which is released from the anterior pituitary gland which in turn activates the thyroid gland



Levels of certain chemicals within the blood- raised blood glucose levels automatically stimulates the release of insulin from the pancreas (Greco, 2001)

However hormones are not only produced in the glands but can also be produced within organs within the body (Schrock, 2001), these include; Gastrin- which is produced by the wall of the stomach, as food enter the stomach via the cardiac spincter, gastrin stimulates the release of bile from the gastric glands and digestion begins Secretin- produced in the wall of the small intestine, as food enter the duodenum from the stomach, secretin stimulated the secretion of intestinal and pancreatic juices which continue the breakdown of food and digestion.

Chorionic gonadotropin- produced during pregnancy by the ectodermal layer of the chorion surrounding the conceptus. It helps to maintain the corpus luteum in the ovary throughout the gestation of pregnancy.

Erythropoietin- produced in the kidney in response to low level of oxygen within the blood, it stimulates the bone marrow to produce erythrocytes or red blood cells.

Hormones are then transported into the blood and then transferred to the tissues elsewhere in the body, this is also achieved with the use of water within the body (‘The encyclopedia of endocrine diseases and disorders’, 2005).

The body is made up of 60-70% of water which is divided into two compartments, these are identified as 

Intracellular fluid (ICF) which is water found within cells within the body



Extracellular fluid (ECF) is the water that lies outside the body cells (World Health Organization (WHO), 2001)

The water and blood within the body, water is vital as this is where the biochemical reactions take place. Whereas Blood which is a cell that is essential within the body as it ensures the internal conditions within the body are kept stable and at a balanced level which enable the body to function correctly this is known as homeostasis (Reece SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

52

et al., 2010). This process allows the water and substances to constantly move around the body, however there are two different processes in which this is achieved, these are known a diffusion and osmosis (Girling, 2003) Diffusion- is the movement of molecules of a liquid or a gas from a high concentration to a low concentration (Tully and Mitchell, 2012, pp. 201 – 202).

Osmosis- is the movement of water through a semi-permeable membrane from a fluid of low concentration to high concentration, this will continue until both concentrates are equal. Semi permeable membranes allow certain molecules to pass through but not all and therefore this allows the body to maintain a constant fluid level within the body which will enable to body to function as it should (Tully and Mitchell, 2012, pp. 93 – 95).

It’s these processes which enable elements to be broken down and the nutrients to be used to allow cells to grow, survive and develop and enable the body to carry out its natural bodily functions (MRCVS et al., 2009a, pp. 71 – 77). A prime example would be protein (which is essential for animal such as dogs to stimulate growth and cell and tissue repair) which is absorbed from foods such as meat, this is then broken down via catabolism (a chemical reaction in which breaks down complex molecules into simple molecules for the use of energy) and due to this breakdown Amino acids are formed and are transported to organs and cells and help with growth and repair and reproduction of cells(Resources and Council with Stress and Nutrition, Board on Agriculture and Renewable Resources, 1981). Without protein and water the cells would become weak, dehydrated and would not be able to grow and function correctly and therefore this and would cause cells and organs to breakdown and die and impact on the animal by causing severe health problems (editors, Fascetti and Delaney, 2011, pp. 9 – 11), which could prove fatal.

Homeostasis also helps the body in other ways, some of these may include this may include: DEFENCE AGAINST DISEASE- The body will detect illness and white blood cells will automatically release to combat and get rid of this infection.

BLOOD CLOTTING-Platelets are released to ensure the blood levels are at the correct substance to be able to continue blood flow and circulation within the body, SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

53

this is done to stop to build up of blood and preventing DVT (deep vein thrombosis) which can be life threatening.

PH REGULATION- animals produce large quantities of acid through their metabolic processes, acids and bases have an electrical charge and therefore seek the opposite material to form a chemical bond and neutralize their overall charge (Campbell, Reece and Meyers, 2005, pp. 901 – 918). For example, bone matter consists of calcium and at least 18 other critical compounds. In the absence of alkaline, excess acid will draw minerals from these sources. Acid which have not been metabolized are usually excreted from the body via urination, urea or sweating, this allows the body to maintain an acid base balance (Campbell, Reece and Meyers, 2005, pp. 901 – 918).

However the body is able to produce hydrogen, in small amounts, and this can unbalance the acid ratio within the body which will in turn increase PH levels within the body (Brooker, 2004). Over all this will increase the concentration of acid within the body, which not only leads to the body being able to maintain it internal balances for daily function but also effects the health and welfare of the animal and may result in deterioration in heath due to dehydration, urinary tract infections, which may result in constipation, loss of appetite and sudden weight loss (Brooker, 2004). Therefore the correct PH balance are essential to minimise the chance of unhealthy chemical reactions.

WATER REGULATION- water is essential for the body to be able to transport nutrients and oxygen to cells and tissues within the body, not only that it is also essential for the process of homeostasis which enable the body to work correctly and enable internal cells and organs to function as they should. Water is also essential for the animal’s survival to prevent dehydration which could prove fatal (Biggs, 2004).

Water also plays a key role in other mechanisms within the body which include:

TEMPERATURE REGULATION Animals' body temperature should remain in a narrow, specific range. Water acts as a buffer against overheating due to water's high specific heat. Specific heat determines how much heat an object can absorb without increasing its own temperature (Kenny, 2010). Water has a high specific heat because its hydrogen-oxygen bonds dissolve SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

54

only when exposed to intense heat. Heated water seeps out through pores in the form of sweat and must be replenished to avoid dehydration (Kenny, 2010). For more detailed information please see Chapter 7: Mechanisms of Thermoregulation page 4041.

All animals must maintain a minimum metabolic rate as this is vital to enable daily functions such as cell maintenance, respiration and steady heartrate (LeaPs, 1899).

Whoever this is very dependent of the whether the animal is endothermic or ectothermic. The minimum endotherm metabolic rate for animal at rest, which is no longer growing and with an empty stomach is known as Basal Metabolic Rate (BMR) but for animals that are ectothermic animals such as snakes and lizards that are reliant on their environment to maintain their internal body temperatures, such as snakes and lizards, this is known as Standard Metabolic Rate (SMR) (Willmer, Stone and Johnston, 2004).

The comparisons of both the BMR and SMR indicate that these animals will have different energy requirements to maintain body temperatures. There are a variety of factors which may affect the metabolic rate this could be age, life stage, species, sex, activity levels and their environment (Willmer, Stone and Johnston, 2004).

The internal system will be able to detect changes which will result the body in releasing messages with will inform the veins and the capillaries which will result in vasoconstriction or vasodilation dependant on the animals temperature (Grigg, 2011), for example in a canine animal such as a dog, the body will detect when body is becoming too hot and will therefore the veins will dilate to allow more oxygen around the body to enable to body to expel heat, which will stimulate the dog to pant to cool down, as described by (Grigg, 2011) who states: “The major blood vessel in a dog's head runs very close to the surface of its nose.

The fresh air a dog breathes works like a fan to cool the blood in the nose, which then circulates through the dog's body to cool the rest of the body. The dog then exhales the warm air out its mouth�

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

55

HYDROLYSIS AND ENERGY PRODUCTION Hydrolysis causes the breakdown of ATP, the molecule that forms when sugar metabolizes in the digestive tract and transfers to all cells (Sherwood, 2006).

According to the Community college of Baltimore County, the introduction of water (two hydrogen atoms and one oxygen atom) to a molecule of ATP (adenosine triphosphate), pulls one phosphate atom away from the molecule, forming adenosine diphosphate also known as ADP. The breaking of this bond releases energy that powers the body(Sherwood, 2006).

DIGESTION Water forms the majority of the mucus lining that protects animal stomachs from the corrosive action of acid. Water passes directly into the intestine and the stomach without the need for digestion. It activates the sodium bicarbonate layer in the mucous membrane of the stomach, protecting it against hydrochloric acid. In addition, saliva, the fluid used to break down food in the mouth, consists mostly of water (Padernal with Marco Med (226 SlideShares), 2013).

JOINT LUBRICATION In any animal skeleton, a protective layer of cartilage rests between bones to provide lubrication and prevent wear on the ends of the bone (MRCVS et al., 2009c, pp. 41 – 44). Articular cartilage, the cartilage that exists in joints, consists of mostly water as well as a matrix of collagens and non-collagenous proteins. Without adequate water, cartilage wears down and restricts the range of motion in a joint (MRCVS et al., 2009c, pp. 41 – 44)

MECHANISMS OF THERMOREGULATION The first line of defence that animal use to maintain body temperature in unfavourable temperatures is behavioural response to manage heat loss or gain (Willmer, Stone and Johnston, 2004). . This may include seeking shelter in hot day or sun in cold day and altering body posture according to temperature to minimize or maximize relative body surface area to alter heat loss or gain are major behavioural response to maintain body temperature, this method is used by cattle (Willmer, Stone and Johnston, 2004).

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

56

Animals can maintain its body temperature within a normal range irrespective of temperature, this is due to the bodies’ metabolic heat production. Control in heat production is controlled by either the autonomic or voluntary thermoregulatory process.

Control of body temperature during cold During cold weather, animals such as penguins should produce more metabolic heat to maintain body temperature and conserve heat. This is achieved in a variety of ways which is due to physiology adaptions, this includes behavioural responses such as penguins huddling together and alternating turns to stand in the centre, this allows the animal to conserve half of its natural body heat (Wood, 2001). The penguin’s feet are small and lined with fat and the animal leans back on their heels which allows heat energy to be absorbed into the body before it’s lost to the environment (Wood, 2001).

Feathers are also sensibly packed and over lapping and waterproof, these feathers are controlled individually and therefore when the temperature drops the penguin will lift the feathers to trap insulated air close to its body (Sumich, 1980) . This allows the thermoreceptors in skin to send signals to the thermoregulatory centres in brain (hypothalamus) which in turn stimulate motor neuron causing increase in muscle metabolism producing more metabolic heat (Sumich, 1980). In long run, animal can maintain the heat production without muscular heat production either by increased activity of the sympathetic nervous system or increased secretion of thyroid hormones (Wood, 2001).

Control of body temperature during hot Feed intake is generally decreased when ambient temperature is increased which results in reduced metabolic heat production and animal prefer to eat (and graze) during cooler part of the day (Aggarwal and Upadhyay, 2013).

Similarly, loss of heat from animal body to surroundings is accelerated during hot temperatures .Elephants lose 80% of their body heat via their ears, this allows their body to regulate its internal temperatures, Elephants are especially adapted to cope

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

57

with tropical climates during hot weather blood circulation to the skin is increased to transfer more heat from core to skin surface (McKay, Cooke and Hutchinson, 2008).

Therefore elephants use different methods to cool down which include swimming and rolling in mud. The mud is vital for the thermoregulation of this species as the mud collects in the folds of the skin, which holds moistures on the top layer of the skin, this moisture then evaporates over time and cools the elephant over time (Institute and Society, 2012), this is a similar method use by humans who evaporate heat loss by sweating to regulate body temperature when temperatures increases above normal body temperature (Institute and Society, 2012). Vaporization of water from sweat causes temperature heat loss which in turn reduces body temperature. Heat loss through evaporation is accountable for loss of heat from metabolic activities and part of that for loss of heat obtained from environment (Aggarwal and Upadhyay, 2013).

PHYSIOLOGICAL MECHANISM TO CONTROL HEAT PRODUCTION

Nervous control of heat production Both central and the nervous system have a role to play in controlling heat production in animal body through secretion of some neurotransmitters (Reece, 2009). Peripheral neurons sends the signal from neuroreceptors in skin to thermoregulatory center central nervous system (hypothalamus). Thermoregulatory center modifies the endocrinal and autonomic nervous activities. Stimulation of sympathetic nervous system produces chemicals which include catecholamines (epinephrine and norepinephrine), prostaglandins, acetylcholine, and 5-hydroxytrytamine which modify metabolism and production of heat (Reece, 2009) Endocrinal control of heat production Thermoregulatory centre also influence the production of some metabolic hormones like

thyroid

hormones

(thyroxine

and

triiodothyronine),

adrenal

hormones

(glucocorticoides) and growth hormone which in turn modifies the heat production from body tissues (Collier and Collier, 2012).

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

58

CONCLUSION In order to ensure I stayed on track with this assignment I decided upon producing a Gantt chart which would enable me to track my work which would enable me to meet the deadline summative date of April 22nd 2015. I produced this chart using a excel programme and it details the task I had to undertake and predicted times to do these tasks.

Figure 37 Gantt chart

Throughout the first few weeks of being given the assignment brief I was able to look at several different platforms for eBooks, and I decided upon using a platform not many people had chosen to use, the main problem with this is I found it very difficult in trying to function the site i.e. inputting images etc. and therefore I had no one I could ask for assistance and therefore it took me several hours of playing with the site to become more confident in my own ability to use it.

I also decided that it would be beneficial to me as an individual to first produce my work in a word document and them publish this work into my eBook at a later date, I decided upon this as it would make my referencing a lot easier and would also stop me from becoming distracted by the layout and formatting of the eBook design. This did prove to be of benefit to me as I was able to amend and add further information

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

59

without changing the format or layout, whereas with the eBook platform I had chosen this would have happened and therefore would have took me extra time to make the alterations back to the original format.

Upon starting the EBook I found it relatively easy to discuss topic such as the respiratory systems, including organs such as the heart and lungs, and the reason for this was I used prior knowledge learnt from the Module “Anatomy and Physiology� which I did during the HNC Animal Management course and therefore felt confident in my abilities to discuss this accordingly.

The most challenged elements of doing this assignment where discussing protein synthesis, the reason for this was due to unforeseen circumstances, I was unable to attend the lecture and therefore missed out on critical information which would have allowed me to complete this section with ease, I therefore had use a variety of external sources such as book, journals and videos to help me understand this topic further.

PROBLEMS THAT OCCURRED During week 7 I tried to transfer information from my word document from word into the eBook template, however I had not attempted to do this prior and therefore came across the problem that text could not be pasted into the document. This ment I had to find a compatible new eBook, which proved difficult as many of the sites offered free eBook however the pages were limited and some incurred a price. I can across a site which allowed me to input all my information in along with charts, images and changes the layout and appearance of my eBook if required.

However with my lack of confidence with computer and new programmes It took me several days to understand how to use the eBook and therefore held me back which resulted me finishing my eBook three weeks later than I had originally planned in my Gantt chart. However this did not cause me to miss the submission date as due to my planning I had the project complete 3 weeks before deadlines where due.

AREAS FOR FUTURE DEVELOPMENT I have thoroughly enjoyed this assignment but have found it very difficult due to the several different aspects which needed covered, on many occasions I have found

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

60

myself going off in different directions and making the work more confusing and complicated than it needed to be. I have since decided to use the format issued to us by the tutor which helped immensely and has allowed me to stay on course and not stray from the original task in hand.

For future reference I would ensure I had looked into different platforms and tried them out before trying to add work so close to completion, this would reduce both time and stop me from panicking and worrying, this problem could have made me miss the deadline date if I wasn’t so far in front and therefore I will be sure to try to illuminate any problems before they arise in the future.

I have always had an issue with condensing my work, this still remains to be an ongoing problem and is proving very challenging to try and conquer. I am person who puts 100% into everything I do and it has been brought to my attention that unfortunately this does include me “rambling” at times. I however have tried my best to combat this by asking a second person to read over my work and suggest possible improvements, identify spelling or grammar issues which need to be resolved and also make me aware of how to make it flow better. I have found this very beneficial and its helping me understand how to be direct and get straight to the point without making it more complicated for myself, which I’m hoping will help me during my future studies.

This eBook is also available online at http://issuu.com/laura8339/docs/biology-_ebook

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

61

BIBLIOGRAPHY

Bibliography

Aggarwal, A. and Upadhyay, R. (2013) Heat stress and animal productivity. New Delhi: Not Avail Alberts, B., Johnson, A. and Walter, P. (2008) Molecular biology of the cell. 5th edn.

United States: Garland Publishing Inc Anonymous (2012) Summary.html 17_25GeneExpressSummary-L.jpg. Available at: http://bio1151.nicerweb.com/Locked/media/ch17/summary.html (Accessed: 29 March 2015) Anonymous (2013) Veins Capillaries And Arteries | Human Body Anatomy. Available at: http://humananatomypics.com/tag/veins-capillaries-and-arteries (Accessed: 17 March 2015) Aspinall, V. (2006) The complete textbook of veterinary nursing. Edinburgh: Butterworth Heinemann Elsevier Aspinall, V. (2011) The complete textbook of veterinary nursing. Edinburgh: Butterworth-Heinemann Ltd BBC (2011) BBC - Higher Bitesize Biology - RNA and protein synthesis _ Print.

Available at: http://www.scribd.com/doc/48688773/BBC-Higher-Bitesize-BiologyRNA-and-protein-synthesis-Print#scribd (Accessed: 29 March 2015) Bemis, W., Liem, K. F., Walker, W. F., Grande, L. and Lauder, undefined (2006) Functional Anatomy of Vertebrates: An Evolutionary Perspective. United States: Brooks Cole Biggs (2004) Biology:dynamics of Life-read.essen. New York, N.Y.: Glencoe/McGrawHill Boyle, M. (2008) Aqa as Biology. 3rd edn. United States: Harper Collins Boyle, M. D. P., Indge, B. and Kathryn (2002) Human Biology (Collins Advanced Science). 2nd edn. United Kingdom: Collins Educational Boyle, M. and Kathryn (2008) Biology (Collins Advanced Science). United Kingdom: HarperCollins Publishers Brooker, R. (2004) Genetics Analysis and Principles (Package). McGraw-Hill Brown, A. G. (2001) Nerve cells and nervous systems: an introduction to neuroscience. London: Springer-Verlag Berlin and Heidelberg GmbH & Co. K Brown, T. (2015) Transcription, Translation and Replication. Available at: http://www.atdbio.com/content/14/Transcription-Translation-and-Replication (Accessed: 29 March 2015) SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

62

Budras, K.-D., Sack, W. O. and Rock, S. (2004) Anatomy of the horse: an illustrated text. Germany: Schlütersche Cajal, S. R. Y., Pasik, P. and Pasik, T. (2002) Texture of the Nervous System of Man and the Vertebrates: An Annotated and Edited Translation of the Original Spanish Text with the Additions of the French Version by Pedro Pasik and Tauba Pasik: Annotated and Edited Translation of the Original Spanish Te. New York: Springer Verlag GmbH Calladine, C. R., Drew, H., Luisi, B. and Travers, A. (2004) Understanding DNA: The Molecule and How it Works. 3rd edn. Amsterdam: Elsevier Academic Press Campbell, N. A., Reece, J. B. and Meyers, N. (2005) Biology: Australian Version.

Australia: Pearson Education Australia (TAFE) Campbell, N. A., Reece, J. B. and Reece, J. B. (2001) Biology. San Francisco: Benjamin-Cummings Publishing Company, Subs of Addison Wesley Longman, Inc Cherniack, N. S. and Widdicombe, J. G. (1985) Handbook of Physiology: Section 3: The Respiratory System Volume II, Parts 1 & 2. An American Physiological Society Book Church, D. C., Pond, W. G. and Pond, K. R. (1995) Basic animal nutrition and feeding.

5th edn. New York: John Wiley and Sons (WIE) Collier, R. J. and Collier, with J. L. (2012) Environmental physiology of livestock. Edited

by J. L. Collier. 1st edn. Ames, Iowa: Wiley, John & Sons, Incorporated Coniel, O. (2012) IB Biology Notes - 6.5 Nerves, hormones and homeostasis.

Available at: http://ibguides.com/biology/notes/nerves-and-hormones (Accessed: 29 March 2015) Cui, S. W. (2005) Food carbohydrates: chemistry, physical properties, and applications. Boca Raton: Taylor & Francis, Inc. Cui, S. W. (2005) Food carbohydrates: chemistry, physical properties, and applications. Boca Raton: Taylor & Francis, Inc. DEMUTH, D (2005) ‘Gregory A. Petsko and Dagmar Ringe, Primers in Biology: Protein Structure and Function, New Science Press, Ltd. (2004) 195 pages.’, Reproductive Toxicology, 19(4), pp. 565–566. doi: 10.1016/j.reprotox.2004.11.001 Darnell, J., Lodish, H. and Baltimore, D. (1990) Molecular cell biology. New York: Scientific American Medicine,U.S.

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

63

Dodds, W. J. and Laverdure, D. R. (2012) The canine thyroid epidemic: answers you need for your dog / W. Jean Dodds, Diana Laverdure. United States: Dogwise Publishing [Ed. by] Mark O.J. Olson ... (2004) The nucleolus. Netherlands: Kluwer Academic / Plenum Publishers Fernandes, M. N., Rantin, F. T. and Glass, M. L. (2007) Fish Respiration And Environment. Edited by B. G. Kapoor and Francisco T. Rantin. 1st edn. United States: Science Publishers,U.S. Frandson, R. D., Wilke, L. W. and Fails, A. D. (2009) Anatomy and physiology of farm animals. 7th edn. United States: Wiley, John & Sons, Incorporated Freeman, W. (2009) 21-05 (Part 3) Blood flow in amphibians | faculty lounge: nonmajors biology. Available at: http://facultylounge.whfreeman.com/?q=node/3208 (Accessed: 30 March 2015) Gerald Karp (2009) ‘Gene Expression: From Transcription to Translation’, in Cell and molecular biology: concepts and experiments. United Kingdom: Wiley, John & Sons, Incorporated, Girling, S. (2003) ‘Basic Reptile and Amphibian Anatomy and Physiology’, in Veterinary nursing of exotic pets. Malden, MA: Blackwell Publishing Ltd, Graham, L. E., Graham, J. M. and Wilcox, L. W. (2002) Plant Biology. United States: Benjamin-Cummings Publishing Company, Subs of Addison Wesley Longman, Inc Graham, L. E., Graham, J. M. and Wilcox, L. W. (2002) Plant Biology. United States: Benjamin-Cummings Publishing Company, Subs of Addison Wesley Longman, Inc Greco, D. (2001) Introduction to Hormonal Disorders of Horses: Hormonal Disorders of Horses: The Merck Manual for Pet Health.

Available at: http://www.merckmanuals.com/pethealth/horse_disorders_and_diseases/hormonal_ disorders_of_horses/introduction_to_hormonal_disorders_of_horses.html (Accessed: 18 March 2015) Gupta, P. K. (2008) Molecular Biology and Genetic Engineering. Meerut, India: Rastogi Publications,India Hargens, A. R. and Wood, S. C. (1991) Physiological adaptations in vertebrates: respiration, circulation, and metabolism. New York: Marcel Dekker Inc Hicks, J. W. (2002) ‘The Physiological and Evolutionary Significance of Cardiovascular Shunting Patterns in Reptiles’, Physiology, 17(6), pp. 241–245. doi: 10.1152/nips.01397.2002 Hillman, S. S., Withers, P. C. and Drewes, R. C. (2008) Ecological and Environmental Physiology of Amphibians (Environmental & Ecological Physiology). Oxford: Oxford University Press, USA

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

64

Hillman, S. S., Withers, P. C. and Drewes, R. C. (2008) Ecological and Environmental Physiology of Amphibians (Environmental & Ecological Physiology). Oxford: Oxford University Press, USA Hosey, G., Bolton, U. of, Melfi, V., Australia, T. C. S., Pankhurst, S. and University, A. R. (2013) Zoo Animals: Behaviour, Management, and Welfare. United Kingdom: Oxford University Press Institute, B. R. and Society, B. R. H. (2012) Uncle John’s Electrifying Bathroom Reader for Kids Only!. United States: Portable Press Johnson, G. B. and Losos, J. (2007) The Living World. Boston: McGraw Hill Higher Education Johnson, george (2007) The Living World. 5th edn. Boston: McCrew Hill Kahn, C. M. and Line, S. (2007) The Merck/Merial Manual for Pet Health: The Complete Health Resource for Your Dog, Cat, Horse or Other Pets - In Everyday Language. Edited by Cynthia M. Kahn. United States: Wiley, John & Sons, Incorporated Karp, G. (2007) Cell Molecular Biology Concepts and Experiments: WITH Student Study Guide: AND Wiley Plus. 4th edn. United States: John Wiley & Sons Inc Kenny, L. (2010) Chapter 42 - Heat and Cold. Available http://www.ilocis.org/documents/chpt42e.htm (Accessed: 30 March 2015)

at:

Kessel, A. and Ben-Tal, N. (2010) Introduction to Proteins: Structure, Function, and Motion. Boca Raton, FL: Taylor & Francis Knight, A. (2008) Single molecule biology. Amsterdam: Academic Press Inc Latchman, D. S. (1995) Eukaryotic Transcription Factors. United States: Academic Press Inc LeaPs, A. (1899) ‘Biology 8th Edition - Campbell and Reece - Part 0004’, Biology, 04 Linzey, D. W. (2001) Vertebrate Biology. United States: McGraw Hill Higher Education MRCVS, V. A. Bvs., Aspinall, V., Cappello, M. and Bowden, S. J. (2009) Introduction to Veterinary Anatomy and Physiology Textbook. 1st edn. United Kingdom: Elsevier Science Health Science div MRCVS, V. A. Bvs., Aspinall, V., Cappello, M. and Bowden, S. J. (2009) Introduction to Veterinary Anatomy and Physiology Textbook. United Kingdom: Elsevier Science Health Science div MRCVS, V. A. Bvs., Aspinall, V., Cappello, M. and Bowden, S. J. (2009) Introduction to Veterinary Anatomy and Physiology Textbook. Oxford: Elsevier Science Health Science div

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

65

Maaske, L. (2012) Your Heart is a Knot!.

Available at: http://mardfar.webs.com/Heart%20evolution%20of%20vertebrates.JPG (Accessed: 17 March 2015) Maina, J. N. (2005) The lung air sac system of birds development, structure, and function ; with 6 tables. Berlin: Springer-Verlag Berlin and Heidelberg GmbH & Co. K Marco Med (226 SlideShares) Follow and Padernal, A. (2013) BIOLOGY BOOK K-12.

Available at: http://www.slideshare.net/marcomed/biology-book-k12 (Accessed: 30 March 2015) Mayer, R. (2003) Genetic Code Facts, information, pictures | Encyclopedia.com articles about Genetic Code.

Available at: http://www.encyclopedia.com/topic/Genetic_Code.aspx (Accessed: 29 March 2015) McKay, G., Cooke, F. and Hutchinson, S. (2008) The encyclopedia of animals: a complete visual guide. 3rd edn. Berkeley: University of California Press Meyer, D. B. (1978) Laboratory guide for human histology. Detroit: Wayne State University Press National Institutes of Health, Department of Health & Human Services (2015) What is DNA?. Available at: http://ghr.nlm.nih.gov/handbook/basics/dna (Accessed: 26 March 2015) Newby, S. (2013) Flashcards - Circulation and gas exchange III - Fish Gills Filaments.

Available at: https://www.studyblue.com/notes/note/n/circulation-and-gas-exchangeiii/deck/6181092 (Accessed: 17 March 2015) Porter, R. (2009) Introduction to Medical Mycolgy (Monographs in Medicine). 3rd edn.

United Kingdom: Wiley, John & Sons, Incorporated Reece, J. (2010) Campbell biology / Jane B. Reece ... [et al.]. 9th edn. Boston: Benjamin-Cummings Publishing Company, Subs of Addison Wesley Longman Reece, J., Urry, L., Cain, M. L., Wasserman, S. R., Minorsky, P. V. and Jackson, R. (2010) Campbell biology / Jane B. Reece ... [et al.]. 9th edn. United States: BenjaminCummings Publishing Company, Subs of Addison Wesley Longman, Inc Reece, J. B., Taylor, M. R. and Simon, E. J. (2011) Campbell biology: concepts & connections. San Francisco, CA: Benjamin-Cummings Publishing Company, Subs of Addison Wesley Longman, Inc Reece, W. (2009) ‘The Endrocrine System’, in Functional anatomy and physiology of domestic animals. Ames, IA: Iowa State University Press, pp. 160–179 endrocine system including glands Reece, W. O. (2009) Functional anatomy and physiology of domestic animals. 4th edn. Ames, Iowa: Wiley, John & Sons, Incorporated

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

66

Ressata, R. (2013) DNA: Definition, Structure & Discovery. Available at: http://www.livescience.com/37247-dna.html (Accessed: 26 March 2015) Rudkin (2006) Handbook of the Hypothalamus. United Kingdom: Taylor & Francis Sardesai, V. (2011) Introduction to clinical nutrition. third edn. United States: Taylor & Francis / CRC Press Schmidt-Nielsen, K. and Schmidt-Nielsen, undefined (1997) Animal physiology: adaptation and environment. 5th edn. New York, NY: Cambridge University Press Sherwood, L. (2006) Study guide for Sherwood’s Human physiology: from cells to systems, sixth edition. United States: Thomson, Brooks/Cole Sherwood, N., etc. and Hoar, W. S. (1994) Fish Physiology: v. 13: Molecular Endocrinology of Fish. United States: New York, Academic Press, 1969Slatter, D. (2003) Textbook of Small Animal Surgery: 2-Volume Set. 3rd edn.

Philadelphia, PA: Elsevier Health Sciences Squires, J. E. (2003) Applied Animal Endocrinology. United Kingdom: CABI Publishing Stewart, M. (1991) Biology: Form and Function: Bk.3: Animal Physiology. United Kingdom: Milton Keynes : Hodder & Stoughton, 1991.

Stress, S. on E., Nutrition, C. on A., Board on Agriculture and Renewable Resources, Resources, C. on N. and Council, N. R. (1981) Effect of environment on nutrient requirements of domestic animals. National Academy Press Sumich, J. L. (1980) An introduction to the biology of marine life. Dubuque, Iowa: W. C. Brown Co. Swan, J. (2014) Chapter 23 circulation [compatibility mode]. Available at: http://www.slideshare.net/ddlg_kau/chapter-23-circulation-compatibility-mode (Accessed: 30 March 2015) The encyclopaedia of endocrine diseases and disorders (2005) Choice Reviews Online, 43(01), pp. 43–0044. doi: 10.5860/choice.43-0044 Tully, T. N. and Mitchell, M. A. (2012) A veterinary technician’s guide to exotic animal care. Lakewood, Colo: American Animal Hospital Association Turnhill, A. (2011) Biological Sciences Bsc 2011 > Crampton > Flashcards > ch 42 CIRCULATION & GAS EXCHANGE. Available at: https://www.studyblue.com/notes/note/n/ch-42-circulation--gasexchange/deck/1406277 (Accessed: 17 March 2015) VOER (2015) Epithelial Tissue. Available at: https://voer.edu.vn/m/epithelialtissue/db3d1db6 (Accessed: 30 March 2015) Vukicevic, S. and Sampath, K. T. (2008) Bone Morphogenetic Proteins: From Local To Systemic Therapeutics. United States: Birkhauser Basel

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

67

Vukicevic, S. and Sampath, K. T. (2008) Bone Morphogenetic Proteins: From Local To Systemic Therapeutics. United States: Birkhauser Basel Willmer, P., Stone, G. and Johnston, I. (2004) Environmental physiology of animals.

22nd edn. Malden, Mass. [u.a.]: Wiley, John & Sons, Incorporated Wood, P. (2001) How penguins are adapted to their environment and survive cold conditions.

Available at: http://www.coolantarctica.com/Antarctica%20fact%20file/science/cold_penguins.htm (Accessed: 30 March 2015) World Health Organization (WHO) (2001) The clinical use of blood in medicine, obstetrics, paediatrics, surgery & anaesthesia, trauma & burns. Switzerland: World Health Organization

[ed. by] Mark O.J. Olson (2004) The nucleolus. Georgetown, Tex: Kluwer Academic / Plenum Publishers Fascetti, A. J. and Delaney, S. J. (2011) Applied Veterinary Clinical Nutrition. 5th edn.

United States: John Wiley & Sons educate (2012) The Baby Brain.

Available http://www.urbanchildinstitute.org/sites/all/files/databooks/2011/ch1-fg2communication-between-neurons.jpg (Accessed: 22 March 2015)

at:

Prepared by John Richard Schrock. (2001) Instructor’s manual to accompany Integrated principles of zoology: eleventh edition; [by] Cleveland P. Hickman, Jr., Larry S. Roberts, Allan Larson. United States: McGraw-Hill Inc.,US

SO112493

HND ANIMAL MANAGEMENT: BIOLOGY

68