Biology integstage2

STAGE 2

INTEGRATIVE ACTIVITY BIOLOGY II UNIVERSIDAD AUTÓNOMA DE NUEVO LEÓN Preparatoria no. 9 Group 220 Natalia Daenna González Viera Luis Roberto González Guajardo Jorge Alberto Cantú Reyes Andrés Eduardo Reyes Gómez Natividad Aron De León Ramírez

SKELETAL SYSTEM • Skeletal • Joints • Bones

The skeleton SKELETON: INTERNAL STRUCTURE THAT PROTECTS AND SUPPORTS THE SOFT ORGANS, TISSUES, AND OTHER PARTS OF VERTEBRATE ORGANISMS, AND IS COMPOSED OF BONE AND CARTILAGE. THE SKELETON IS NEEDED TO PROVIDE SUPPORT FOR THE WHOLE BODY. THERE ARE 206 BONES IN THE ADULT HUMAN SKELETON. THE SKELETON IS DIVIDED INTO: Ø AXIAL SKELETON: IT SUPPORTS THE CENTRAL AXIS OF THE BODY; AND IT CONSISTS OF THE SKULL, THE VERTEBRAL COLUMN, AND THE RIB CAGE. Ø APPENDICULAR SKELETON: IT IS FORMED BY THE BONES OF THE ARMS AND LEGS, ALONG WITH THE BONES OF THE PELVIS AND SHOULDER AREA. FUNCTIONS OF THE SKELETON: • • • • •

SUPPORTS THE BODY PROTECTS INTERNAL ORGANS ASSIST MOVEMENT STORES MINERALS IT IS A SITE OF BLOOD CELL FORMATION

Bones BONES: THE DENSE, SEMI RIGID, POROUS, CALCIFIED CONNECTIVE TISSUE FORMING THE MAJOR PORTION OF THE SKELETON OF MOST VERTEBRATES. SOLID NETWORK OF LIVING CELLS AND PROTEIN FIBERS THAT ARE SURROUNDED

BY DEPOSITS OF CALCIUM SALTS.

STRUCTURE OF BONES THE BONE IS SURROUNDED BY A TOUGH LAYER OF CONNECTIVE TISSUE CALLED PERIOSTEUM. BENEATH THE PERIOSTEUM IS A THICK LAYER OF COMPACT BONE. NERVES AND BLOOD VESSELS RUN THROUGH COMPACT BONE IN CHANNELS CALLED HAVERSIAN CANALS. A LESS DENSE TISSUE KNOWN AS SPONGY BONE MAY BE FOUND UNDER THE OUTER LAYER OF THE COMPACT BONE, IT COULD BE FOUND IN THE ENDS OF LONG BONES AND IN THE MIDDLE OF SHORT, FLAT BONES. SPONGY BONE IS QUITE STRONG; THE LATTICEWORK STRUCTURE IN SPONGY BONE ADDS MORE STRENGTH WITHOUT ADDING EXCESS MASS.

MANY BONES ARE CAVITIES THAT CONTAIN A SOFT TISSUE CALLED BONE MARROW, AND THERE ARE TWO TYPES: Ø YELLOW MARROW: IT CONSISTS PRIMARILY OF CELLS THAT STORE FAT. Ø RED MARROW: IT CONTAINS STEM CELLS THAT PRODUCE MOST TYPES OF BLOOD CELLS.

Joints JOINT: A PLACE WHERE ONE OR MORE BONES MEET ANOTHER BONE. TYPES OF JOINTS ACCORDING TO ITS TYPE OF MOVEMENT v IMMOVABLE JOINTS: OFTEN CALLED FIXED JOINTS, ALLOW NO MOVEMENT. v SLIGHTLY MOVABLE JOINTS: PERMIT SMALL AMOUNT OF MOVEMENT. v FREELY MOVABLE JOINTS: PERMIT MOVEMENT IN TWO OR MORE DIRECTIONS. FREELY MOVABLE JOINTS ARE GROUPED ACCORDING TO THE SHAPES OF THE ADJACENT BONES, IN:

ü BALL-AND-SOCKET: FOUND IN THE SHOULDERS AND HIPS, THESE JOINTS ALLOW FOR MOVEMENT IN MANY DIRECTIONS. ü PIVOT: ALLOW ONE BONE TO ROTATE OR TURN AROUND ANOTHER. ü SADDLE: ALLOW ONE BONE TO SLIDE IN TWO DIRECTIONS. THEY ALLOW A THUMB TO MOVE ACROSS A PALM.

ü HINGE: PERMIT BACK-AND-FORTH MOTION, LIKE THE OPENING AND CLOSING OF A DOOR. THEY ARE FOUND IN THE ELBOWS, KNEES, AND ANKLES.

MUSCULAR SYSTEM • Skeletal muscle • Muscles contraction • Muscles and Movement

Muscular System

The muscular system is an organ system consisting of skeletal, smooth and cardiac muscles. It permits movement of the body, maintains posture, and circulates blood throughout the body. The muscular system in vertebrates is controlled through the nervous system, although some muscles (such as the cardiac muscle) can be completely autonomous. Together with the skeletal system it forms the musculoskeletal system, which is responsible for movement of the human body.

Skeletal Muscle Skeletal muscles are the only voluntary muscle tissue in the human body and control every action that a person consciously performs

Smooth Muscle Smooth, muscle is found inside organs such as the stomach and intestines, as well as in blood vessels.

Cardiac Muscle Found only in the heart, cardiac muscle is an involuntary muscle responsible for pumping blood throughout the body.

Muscle Contractions How do the bones of the human skeleton move? Skeletal muscles contract and relax to mechanically move the body. Messages from the nervous system cause these muscle contractions. The whole process is called the mechanism of muscle contraction and it can be summarized in three steps: (1) A message travels from the nervous system to the muscular system, triggering chemical reactions.

(2) The chemical reactions lead to the muscle fibers reorganizing themselves in a way that shortens the muscle--that’s the contraction.

(3) When the nervous system signal is no longer present, the chemical process reverses, and the muscle fibers rearrange again and the muscle relaxes.

Muscles and Movement At the simplest level, muscles allow us to move. Smooth muscle and cardiac muscle move to facilitate body functions like heartbeats and digestion. The movement of these muscles is directed by the autonomic part of the nervous system—those are the nerves that control organs. Skeletal muscles move our bodies in space. They take direct instruction from the specific nerves that innervate each muscle.

How do skeletal muscles move? It happens when the muscular system and the nervous system work together: Somatic signals are sent from the cerebral cortex to nerves associated with specific skeletal muscles. Most signals travel through spinal nerves that connect with nerves that innervate skeletal muscles throughout the body. Want to flex an elbow joint? Your cerebral cortex sends a signal through your spinal nerve to the nerves that innervate muscles around the elbow joint.

When that signal reaches the muscle tissue its cells reorganize, causing a contraction that bends the elbow joint!

THE SKIN: INTEGUMENTARY SYSTEM • Functions • Structures • Skin Problems

Integumentary System The integumentary system consists of the skin, hair, nails, glands, and nerves. Its main function is to act as a barrier to protect the body from the outside world. It also functions to retain body fluids, protect against disease, eliminate waste products, and regulate body temperature. In order to do these things, the integumentary system works with all the other systems of your body, each of which has a role to play in maintaining the internal conditions that a human body needs to function properly.

Hair:

The basic component of human hair and nails is keratin.

Nails: Nails begin to grow in the nail root and grow at an average of 3mm/month.

Functions: The integumentary system has many functions, most of which are involved in protecting you and regulating your body’s internal functions in a variety of ways: -

Protects the body's internal living tissues and organs Protects against invasion by infectious organisms Protects the body from dehydration Protects the body against abrupt changes in temperature Helps dispose of waste materials Acts as a receptor for touch, pressure, pain, heat, and cold Stores water and fat Excretion Temperature regulation Vitamin D production

Structures: EPIDERMIS: Have inner and outer layers. Also produce keratin and a pigment called melanin that are produced by melanocytes and that help us with the ultraviolet rays.

DERMIS: Contains proteins, collagens, blood vessels, nerves, glands, sensory receptors, etc. Regulate the body temperature with the sweat glands. Have sebaceous glands that secrete an oil called sebum, and the sebum help to keep the keratin.

HYPOTHERMIS: This layer only contains fats.

Skin Problems: ACNE

HIVES

SKIN CANCER * Basal cell carcinoma * Melanoma * Squamous cell carcinoma