The document summarizes the key processes of the digestive, respiratory, circulatory, and excretory systems. It describes the three main stages of digestion - in the mouth, stomach, and small intestine. It then explains the role of the lungs in respiration, absorbing oxygen and expelling carbon dioxide. It outlines the major components of circulation - blood, blood vessels, and heart - and their functions in transporting blood throughout the body. Finally, it summarizes the excretory system and role of kidneys, ureters, bladder, and urethra in filtering waste from the blood and releasing it from the body as urine.

1. NUTRITION
CEIP ALMIRANTE LAULHÉ
(San Fernando)

2. Digestive system
Stage 1
It begins in the mouth,
where our teeth break down
food. While we chew, the
food mixes with saliva. This
mixture is called a bolus.
Stage 2
The bolus reaches the
stomach, which produces
gastric juices. These juices
form a thick mixture called
chyme.
Stage 3
The chyme travels to the
small intestine, which
produces intestinal juices.
These juices turn * the
chyme into a liquid called
chyle.
Digestion is the process of breaking down* food into nutrients. It usually takes our body 24 to
48 hours to digest food. Digestion takes place in the digestive system. It consists of one long
tube, called the digestive tube, and the helper glands.
These are the stages of digestion:
* Breaking down: descomposición
* To turn into: convertir

3. Digestive system
Nutrients are absorbed into the blood in the small intestine.
In the large intestine , the remaining undigested food turn into
faeces.
Faeces leave the body through the anus.

4. Respiratory system
Respiration is the process by which we
breathe in, or inhale, to obtain the oxygen
our body needs, and we breath out, or
exhale, to expel the carbon dioxide our body
produces. Respiration takes place in the
respiratory system. It consists of the air
passageways * and the lungs.
* Air passageways: vías respiratorias
* Branches: ramificaciones
When we inhale, air enters through the
nostrils , goes to the pharynx, then travels
down the larynx and the trachea. The trachea
is divided into two branches * called the
bronchi. The bronchi take the air to each lung.

5. Respiratory system
Inside the lungs, the bronchi are divided into smaller
branches called bronchioles. The bronchioles lead to
the air sacs.
The oxygen in the air we inhale passes from the air
sacs into the blood. The blood carries the oxygen to
all the cells in our body.
The carbon dioxide produced by our body passes into
the air sacs.
The air sacs expel the carbon dioxide when we exhale.

6. Circulatory system
Blood
Blood is a liquid substance in
our body that reaches all the
body cells.
Blood vessels
Blood vessels are tubes which transport blood
throughout the body. There are three types:
Arteries carry blood away from the heart
towards all body tissues.
Veins carry blood back to the heart from all body
tissues.
Capillaries have very thin walls. This allows for
nutrients and oxygen to pass into the body cells,
and for carbon dioxide to leave the cells.
The heart
The heart is a special type of muscle.
It acts as a pump * to send blood
around the body through the blood
vessels. The heart has four chambers:
- the right and left atria* , where
blood enters the heart.
- the right and left ventricles, where
blood leaves the heart.
The circulatory system consists of blood, blood vessels and the heart.
* Pump: bomba
* Atria: aurículas

7. Circulatory system
Circulation is the movement of blood through the
circulatory system.
Blood carries * nutrients and oxygen to all parts of the
body. It also collects * carbon dioxide and other waste
products which need to be eliminated.
Blood moves constantly in the circulatory system.
* To carry: llevar
* To collect: recoger

8. Excretory system
Excretory system
The excretory system consists of the kidneys,
the ureters, the bladder and the urethra.
Excretion happens when blood reaches the
kidneys. The kidneys filter the blood, retain
waste products and use them to produce
urine.
Then, the ureters carry urine from the kidneys
to the bladder. Urine is stored in the bladder
until it leaves the body through the urethra.
Excretion is the elimination of waste products from the blood.
Excretion takes place in the excretory system and the sweat glands.

9. Sweat glands
Sweat glands are long, coiled* tubes that are located
inside the skin. Each sweat gland connects to a pore
on the surface of the skin.
Sweat is formed in the sweat glands. It consists mainly
of water, but it also contains mineral salts and waste
products. When sweat is secreted through pores
waste products are eliminated. This is why sweat
glands are considered part of the excretory system.
* Coiled: enrollado
pore
sweat
gland

10. Now it’s your turn!
1 . Match each function to a process involved in nutrition.
● obtaining nutrients from food.
● eliminating waste.
● obtaining oxygen.
● transporting nutrients, oxygen and waste substances.
2 . Answer the questions.
Which blood vessels connect arteries and veins?
Which part of the circulatory system is responsible for pumping blood?
3 . Correct the mistakes. Then, write a number to order the sentences.
The urethra carries urine from the kidneys to the bladder.
Urine is stored in the ureters.
The kidneys filter the blood and produce nutrients.
Urine leaves the body through the bladder.