2. The function of nutrition
gives our cells energy and
oxygen. The digestive
, respiratory ,circulatory and
excretory system take part
in nutrition.
3. Digestion is the process in which food changes into nutrients.
It takes place in the digestive system , which has two parts:
·Te digestive tract : it is a long muscular tube about
eight metres long. Its parts are the
mouth, pharynx, oesophagus, stomach, small intestine and
large intestine.
· Glands : They release chemicals to the digestive tract to
help with digestion . They are the salivary glands, the liver
and the pancreas.
4.
5. Breathing is the process where the body takes
in oxygen and releases carbon dioxide.
Lung ventilation: Inhaling is when air goes
into lungs.
Exchange of gases: The oxygen breathed in
goes to the blood and the carbon dioxide
from the blood moves to the lungs where it is
released outside the body.
6. Respiratory tract: It is made made up of passages
throung which air enters and leaves the body.
Lungs: They are two spongy organs made up of
millions of small bags called alveoli, where gases
are exchanged.
7. Excretion is the elimination of the waste
substances collected in the blood that cells
have produced. The excretory system is in
charge of excretion and it is made up of:
Sweat glands They are in the skin and
produce sweat.
Urinary system
8.
9.
10. _ Kidneys They take substances out of the
blood, mix it with some water and make urine.
_ Urinary tract It takes, stores and releases the
urine.
11.
12. Circulation is the transportation of blood
throungh the circulatory system.
Heart: It is a hollow, muscular organ that
pumps blood so that it reaches the entire
body.
13. Blood It collects oxygen from the alveoli
And nutrients from the small intestine and
transports them to all of the body.
Blood vessels They are the tubes through
which blood circulates.
_ Arteries They are blood vessels that carry
blood from the heart to the rest of the body.
_ Veins They are the blood vessels that carry
entire body back to the heart.
14. _ Capillaries They are very thin vessels that
reach all the cells of the body.
15. BLOOD
Blood is a read liquid tissue made up of
cells that float the nutrition liquid called
plasma.
Blood cells There are different types
of cells.
_ Red blood cells: Most are of this type.
_ White blood cells: They are the body´s
defence.
16. _ Platelets They form blood clots in blood
vessels to stop blood form coming out when
they are broken.
Blood plasma It is a liquid made up of water
with dissolved salts and nutrients.
17. It is a muscular organ located in the chest.
It is divided into two parts separated by a wall
called the heart septum.
Atrium It is the upper cavity.
Ventricle The cavity is smaller.
Systole: It is the movement of contraction.
Diastole: It is the movement of relaxation.
18. Mammals have a closed circulation because
blood full of oxygen or carbon dioxide do not
mix.
19. Human circulation is double because it has a
pulmonary or minor circulation and a general or
major circulation.
