SCIENCE

The function of nutrtion

The function of nutrition gives our cells all the energy they

need.

Four body systems carry out the function of nutrition:

-Digestive system.

-Respiratory system.

-Circulatory system.

-Excretory system.

Digestion and the digestive

system Digestion is the processes in which food changes

into nutrients.

The digestive system has two parts:

-The digestive tract: Its parts are the

mouth, the pharynx, the oesophagus, the

stomach, the small intestine and the large

intestine.

-Glands: They release chemicals.They are the

salivary glands, the liver and the pancreas.

The digestive system

Breathing

Breathing is the processes where the body

takes in oxigen and releases carbon dioxide.

Two processes take place:

-Lung ventilation: Inhaling is when air

goes into the lungs.Exhaling sends air out

of the lungs.

-Exchange of gases: The oxigen breathing

in goes to the blood and the carbon dioxide

from the blood moves to the lungs.

The respiratory system

The respiratory system carries out

breathing. It consists of:

-Respiratory tract: It is made up of

the nostrils, larynx, pharynx, trachea,

bronchi and bronchioles.

-Lungs: They are two spongy organs

made up of millions of small bags

called alveoli, where gasses are

exchanges.

The respiratory system

Excretion and the excretory

system

Excretion is the elimination of waste

substance collected in.

The excretory system is made up of:

-Sweat glands: They are in the skin and

produce sweat.

-Urinary system: Is made up of:

-Kidneys.

-Urinary tract.

The urinary system

Circulation and the circulatory

system

Circulation is the transportation of

blood through the circulatory

system, carrying nutrients and oxigen to

all the cells and collecting waste

substances.

The circulatory system is made up of:

-Heart.

-Blood.

-Blood vessels.

Heart

It is divided into two parts separated by a

wall called the heart septum.

Each half of the heart is divided into two

cavities:

-Atrium: It is the upper cavity.

-Ventricle: the cavity is smaller.

The heart uses rhythmic systole and

diastole movements to pumps blood.

Blood

It collects oxigen, nutrients, carbon dioxide

and waste substances.

Blood cells: There are different types of

cells:

-Red blood cells: They carry oxigen.

-White blood cells: They are the body’s

defence cells.

-Platelets: They form blood clots.

Blood plasma.

Blood

Blood vessels

They are three types:

-Arteries: They carry blood from the

heart to the rest of the body.

-Veins: They carry blood from the

entire body back to the heart.

-Capillaries: They are very thin

vessels.

The circulatory system

The end