_?_ carry deoxygenated blood from the capillaries to the heart.

Blood enters the heart through the _?_, then it flows into the _?_ where it is pumped out.

They are special flaps that stop blood from flowing backwards.

How long does food take to pass through the digestive system?

It is a ball of chewed food mixed with saliva.

It covers the trachea and stops food from going into our lungs.

Break down the food in out stomach and kill dangerous bacteria.

It is a mixture of food and gastric juices.

Chyme mixes with bile and pancreatic juices, which break the chyme down into basic nutrients. The nutrients pass through the walls of the intestine and are absorbed into the blood.

Salivary glands, bolus and oesophagus.

Plasma, platelets and arteries.

Trachea, bronchi and bronchioles.

Alveoli and lungs

Veins, atrium and ventricle.

Epiglottis, liver and pancreas.

Aorta and vena cava.

When fresh air reaches the _?_ , there is a gas exchange.

_?_ passes through the walls of the alveoli and into the blood.

_?_ passes out of the blood and into the alveoli.

We _?_ oxygen.

We _?_ carbon dioxide.

Choose the correct order for inhalation.

The diaphragm relaxes and moves up. The lungs deflate and the ribcage contracts.

The diaphragm contracts, becomes flatter and moves down. . The lungs inflate and the ribcage expands.

Carry blood from the capillaries to the rest of the body. The blood they carry is oxygenated.

Tiny blood vessels with very thin walls which help gasses and other substances to pass through them easily.

Carry blood from the capillaries to the heart. The blood they carry is deoxygenated.

They carry oxygen and carbon dioxide.

They fight infections by attacking bacteria and viruses that enter the body.

They are particles that join together when there is a cut in the skin to stop the bleeding.

It is 90% water. It also carries nutrients and waste products.

Letter A is the _?_ .

Letter B is the _?_ .

Letter C is the _?_ .

Letter D is the _?_ .

Letter E is the _?_ .

Letter F is the _?_ .

Letter G is the _?_ .

A is the _?_ .

B is the _?_ .

C is the _?_ .

D is the _?_ .

E is the _?_ .