Human body nutrition 1

1 C.E.I.P. SANTA ANA (Madridejos)

UNIT 1. NUTRITION I DIGESTIVE & CIRCULATORY SYSTEMS SCIENCE 6.

CONTENTS: 1.– Nutrition: digestive, circulatory, respiratory & excretory.

2.– Types of nutrients: 3.– Digestive system: 3.1.– Digestive tract, digestive glands. Digestive process.

3.2.– Protect your health: food pyramid & diet.

4.– Circulatory system: 4.1.– Blood components.

4.2.– Blood vessels.

4.3.– Heart.

4.4.– Blood circulation.

4.5.– Protect your health.

NUTRITION is the process in which living beings get oxygen and nutrients, that they use to get energy and grow. Later they expel waste products.

CIRCULATORY SYSTEM: Carries nutrients and oxygen to every cell, and removes CO2 and waste products from cells to the exterior.

DIGESTIVE SYSTEM: Transforms food into nutrients, that go to the blood, and expels waste products to the exterior.

Some systems work together in NUTRITION: .– CIRCULATORY SYSTEM. .– DIGESTIVE SYSTEM. .– RESPIRATORY SYSTEM. .– EXCRETORY SYSTEM.

EXCRETORY SYSTEM: Produces urine and sweat and expels waste products from cells to the exterior .

RESPIRATORY SYSTEM: Gets oxygen from the air, passes to the blood and removes CO2 from blood, and expels to the exterior.

2.– TYPES OF NUTRIENTS: Nutrients are components (mostly There are different types of nutrients, like carbohydrates, fats, proteins, vita- in foods) that an organism uses to mins, and there are inorganic nutrients like, minerals, water and oxygen. survive, get energy and grow.

A.– Carbohydrates are needed to give the body energy. We can find them in cereals, potatoes, pasta, flour, and in sugars (in fruits, honey…)

B.– Fats are concentrated sources of energy, and help to insulate in cold weather. There are animal and vegetable fats. (meat, butter, olive oil…)

C.– Proteins help to grow and form tissues in the body. We can find them in meat, fish, milk, cheese, dairy products, eggs…

D.– Vitamins are needed in small amounts for growth and and be healthy. There are different kinds of vitamins with different properties.

E.– Minerals are needed in small amounts to help the body on vital functions, and to be healthy and strong (Examples: calcium, Iron, sodium, potassium…) We can find them in fruit, vegetables, water...

1 f.– Water is needed for life. Living beings are composed by water in a high proportion. If they don’t have enough water, they will be dehydrated and die.

USEFUL WORDS: .– respiratory system .– fats

.– nutrition .– excretory system. .– proteins

.– circulatory system .– nutrients .– vitamins

.– Digestive system .– carbohydrates .– minerals.

2 3

C.E.I.P. SANTA ANA (Madridejos)

2

Digestion is the process of breaking down food molecules 3.– DIGESTIVE SYSTEM: The digestive system is formed by the digestive tract into smaller substances called nutrients. Nutrients pass to and some glands that cooperate to the digestion process. the blood, and waste productucts are expelled.

3.1.– A) DIGESTIVE TRACT: is a muscular tube formed by mouth, the pharynx, the oesophagus, stomach, small intestine, large intestine, the rectum and the anus.

This tube is formed by muscle tissue that moves the food down with their contractions.

4

SALIVARY GLANDS: produce saliva to moist food and break down carbohydrates MOUTH: with teeth and tongue. It breaks down food into parts.

PHARYNX: controls that food goes down to the esophagus.

5

OESOPHAGUS: transports food from mouth to stomach.

STOMACH: produces mechanical contractions and gastric juice to break down food.

LIVER: produces bile for fats digestion. It makes other vital functions.

PANCREAS: produces pancreatic juice into small intestine.

GALL BLADDER: stores bile from liver.

SMALL INTESTINE: produces juices and there, nutrients, vitaminns, minerals, water… pass to the blood.

6 RECTUM: stores the waste products (faeces) to expell them.

7

LARGE INTESTINE: water is absorbed, and waste products are transformed into faeces.

ANUS

B) DIGESTIVE GLANDS: are glands that produce different liquids which help to dissolve food into nutrients. .– Salivary glands produce saliva to moist food and form the bolus. .– Microscopic glands in the stomach produce gastric juice, to form the chyme. .– Liver produce bile, that is a liquid to help to divide fats. The gallbladder stores bile from the liver. .– Pancreas produce pancreatic juice to help in digestion. .– Microscopic glands in the small intestine produce intestinal juice to form the chyle.

C) DIGESTIVE PROCESS, or DIGESTION. Digestion is the process of breaking down food molecules into smaller substances called nutrients. Nutrients pass to the blood, and waste productucts are expelled.

1.- Digestion in the mouth: Teeth break down food into pieces, salivary glands produce saliva and the tongue mixts it with the small pieces of food to form the bolus.

Saliva also starts to dissolve carbohidrates in the mouth.

USEFUL WORDS: .– digestive tract .– stomach .– rectum .– gastric juice .– gall bladder

.- pharynx .- small intestine .– anus .– chyme .– páncreas

.– oesophagus .– large intestine .– salivary glands .– bile .– chyme .- chyle

teeth

tongue 8

9

C.E.I.P. SANTA ANA (Madridejos)

2.– Digestion from the mouth to the stomach: The tongue pushes the bolus to the pharynx, then we swallow and the bolus goes to the oesophagus.

The oesophagus is a muscular tube that help the bolus to get to the stomach. Movements that digestive tract do are called peristalsis.

The stomach is a muscular bag with microscopic glands that produce some juice called gastric juice.

pharynx

oesophagus

This substance is very acid, and it continues dissolving the food.

The stomach contracts and moves, and it mixes the food with the gastric juice forming a paste called chyme.

stomach 10

small intestine

3.– Digestion in the small intestine: The chyme goes to the small intestine, where it mixes with the bile from the liver, the pancreatic juice and the intestinal juice from glands in the small intestine to form the chyle.

The small intestine is a muscular tube about seven metres long with millions of intestinal villi. These small hairs have got capillaries that absorb nutrients to the bloodstream.

intestinal villi

capillaries: artery & vein

11

Large intestine 4.– Digestion in the large intestine: Large intestine is a muscular tuve, shorter and wider than the small intestine.

The substances that weren’t absorbed go to the large intestine.

There, juices, water and some minerals are absorbed.

The rest of materials form the faeces. They are stored in the rectum, and are expelled through the anus. apendix rectum USEFUL WORDS: .– gastric juices .- pancreatic juice .– peristalsis

anus .– chyme .- chyle .- rectum

.– bile .– intestinal villi .– anus

12

3

13

C.E.I.P. SANTA ANA (Madridejos)

4

3.2.– PROTECT YOUR HEALTH : There are some rules related with the digestive system to avoid problems with our health. Some are related with hygine, and others with diet: .- Wash your hands before cooking or before having every meal.

Some microorganisms can produce infections in our digestive tract. .– Wash fruit and vegetables before eating them. .– Clean your teeth two or three times a day. .– Keep a balanced and healthy diet.

14 Some microorganisms feed from remains of food, producing some substances that attack our teeth and create caries.

Food pyramid and healthy diet.

If you eat a balanced diet, your organs and systems will work better.

Eating a great variety of foods is needed to be healthy.

So you must...

1.– Eat a lot of vegetables, cereals, pasta, fruits… These foods contain different nutrients (minerals, vitamins, fibre…)and lots of energy from carbohydrates. And don’t forget to drink a lot of water or liquids.

2.– Eat moderately fish, meat, eggs, dairy food (milk, yogourt…) will provide proteins, minerals and vitamins to grow and stay healthy.

3.– Eat in small amounts: sugars, sweets, oil and animal fats. They can provoque healthy problems.

Don’t forget to drink two litres of liquids a day.

15

USEFUL WORDS: .– dairy products .– whole grains

.– poultry .– whole wheat .

.– sugary drinks – weight control

16

17

C.E.I.P. SANTA ANA (Madridejos)

4.– CIRCULATORY SYSTEM. The circulatory system is formed by blood vessels (arteries, veins and capillaries), heart and the blood.

This system transports different substances in the body floating in the blood:

5

The Circulatory system carries nutrients and oxygen to every cell, and removes CO2 and waste products from cells to the exterior.

.– Oxygen that lungs get from the air, and is carried to cells. .– Nutrients: proteins, glucose, minerals… (from the small intestine). .– Carbon dioxide and waste products formed by the transformation of nutrients and oxygen in cells.

Blood components: plasma, platelets, red blood cells, and white blood cells.

18

4.1.– BLOOD COMPONENTS: Blood is a thick red liquid formed by different components: plasma and blood cells. a.– Plasma is a yellow translucent liquid formed mostly by water, where blood cells, nutrients and waste products are floating. b.– Red blood cells (erythrocytes) are red disk-shaped that transport oxygen from the lungs to cells, and CO2 from cells to lungs. c.– White blood cells (leukocytes) protect our body from microorganisms and viruses. Our body produce more leukocytes when we are sick. d.– Platelets heal wounds and form a blood clot to avoid bleeding. red blood cells

platelets

white blood cell

plasma

Platelets forming a Blood clot 19

4.2.– BLOOD VESSELS: They are tubes that contains blood, and transport it to every cell in our body.

There are three types:

Blood vessels: .– Arteries .– Veins .– Capillaries

A.– Arteries carry blood away from the heart to the organs.

B.– Veins carry blood from the organs to the heart. Veins have valves to help that the blood only circulates in one direction (forward).

20

C.– Capillaries are very narrow tubes that connect arteries and veins. They permit the exchange of gases and substances between blood and every cell.

In the capillaries of the arteries, oxygen and nutrients go out to cells.

In the capillaries of veins, CO2 and waste products pass to the blood. .– blood vessel .– blood clot .– arteries

.– plasma .– platelet .– veins

.– red blood cell .– white blood cell .– capillaries

C.E.I.P. SANTA ANA (Madridejos)

6

4.3.– THE HEART. The heart is a muscular organ that pumps blood through the Right part of heart: CO2 / Left part of heart: O2 Blood enters to the atrium, and goes out through blood vessels around the body. It beats about 72 beats/minute. the ventricle It’s divided in two halves: The right side with blood rich in CO2, and the left side with Left part Right part blood rich in O2.

The heart has got four chambers: right atrium, left atrium, right ventricle and left ventricle.

Blood enters in the atrium (upper part) through veins, pass through a valve to the ventricle (lower part) and goes out to the body through arteries.

The heart contracts and expands to pump blood, this movement is called beat.

Every beat has got two steps: 1.– The heart expands (diastole) and blood enters from the veins.

2.- The heart contracts (systole) and pumps blood through arteries.

SYSTEMIC CIRCULATION

PULMONARY CIRCULATION

4.4.– BLOOD CIRCULATION: Blood circulation is the route your blood takes around the body. It has 2 circuits: .– Pulmonary circulation: when the blood goes from the heart to the lungs to release CO2 . to get oxygen and returns. .– General circulation (or systemic): is the circulation of the blood to all parts of the body except the lungs (releases O2 in cells and gets CO2 ).

PULMONARY CIRCULATON: 1.- Blood leaves the right ventricule and goes through the pulmonary arteries to the lungs.

2.- In the lungs arteries become capillaries, where blood releases CO2 and gets oxigen.

3.- Blood returns through the pulmonary veins to the heart. Blood comes into the left atrium.

4.– Blood passes from the right atrium to the right ventricle and to the lungs, and pulmonary circulation starts again.

SYSTEMIC CIRCULATION: 1.– Blood passes from the left atrium to the left ventricle, and goes out through the aorta artery to the rest of the body.

3.- Blood rich in CO2 comes from capillaries to veins. Finally the largest vein (vena cava) carries blood to the right atrium.

23

.– right atrium .– beat .– vena cava

22

21

2.– Aorta (the largest artery) is divided into other arteries and finally into capillaries, where blood releases O2 and gets CO2 from cells.

24

.– left atrium .– right ventricle .– left ventricle .– systole .– diastole .– aorta artery .– pulmonary circulation .– systemic circulation

25

26

27

C.E.I.P. SANTA ANA (Madridejos)

7

3.2.– PROTECT YOUR HEALTH : First we are going to learn about the most common problems with the circulatory system, and later we’ll see some rules to avoid them. These kind of deseases are typical for adult people, but we must always keep healthy habits.

A.– PROBLEMS ON THE CIRCULATORY SYSTEM. 1.– Hypertension or high blood pressure is a problem. When the blood pressure in arteries is too high over the years, it can do some damages to arteries, to the heart (heart attack), to the brain (stroke)..

Adults must control their level of blood pressure.

28

2.– Cholesterol is a kind of fat. We get it from animal fats from food.

When the level of cholesterol is high, it can cause blockage of blood flow in arteries (atheroma).

3.– Arteriosclerosis is the thickening, hardening and the loss of elasticity of the walls of arteries. This process provoque that cells in organs or tissues get less blood than in normal conditions.

Cholesterol and arteriosclerosis can provoque arteries become narrower and narrower.

4.– Heart attack is usually caused by a blood clot (in coronary arteries), which stops the blood flowing to a part of the heart muscle, so cells from the heart will die.

B.– WHAT WE MUST DO TO PREVENT THESE PROBLEMS: 1.- Adults must control their blood pressure and their level of cholesterol. So adults must check them regularly.

29

To keep them under control we must do: 2.– Keep a healthy diet is a good way of regulate the levels of colesterol and blood pressure: .– Eat lots of vegetables and fruit. .– Eat more fish like salmon, blue fish… .– Eat legumes (lentils, chickpea…) and nuts. .– Low salt intake.

3.– Don’t smoke, and use alcohol drinks moderately. These substances are very dangerous for blood vessels, and they can provoque important problems on them.

4.– Practice sports and do exercise regularly. They are the best way to feel good and stay healthy.

30

Practice sports and do exercise regularly.

31

32

USEFUL WORDS: .– hypertension / high blood pressure .– arteriosclerosis

.– cholesterol .– heart attack