Circulatory system - The heart

Question 1

What is the circulatory systems main function?

Answer 1

• To get food and oxygen to every cell in the body

- To carry waste products (e.g. Carbon dioxide and urea) to where they can be removed from the body.

Question 2

What do humans have?

Answer 2

A double circulatory system (two circuits joined together).

Question 3

What does the first circuit of our double circulatory system do?

Answer 3

It pumps deoxygenated blood to the lungs to take in oxygen. The blood then returns to the heart.

Question 4

What does the second circuit of our double circulatory system do?

Answer 4

It pumps oxygenated blood around all other organs of the body. The blood gives up its oxygen at the body cells, and the deoxygenated blood returns to the heart to be pumped out to the lungs again.

Question 5

What does the heart do?

Answer 5

It contracts to pump blood around the body.

Question 6

What is the heart?

Answer 6

A pumping organ that keeps the blood flowing around the body.

Question 7

What are the walls of the heart mostly made of?

Answer 7

Muscle tissue.

Question 8

Why does the heart have valves?

Answer 8

To make sure that blood goes in the right direction, they prevent it from flowing backwards.

Question 9

What are the hearts four chambers?

Answer 9

• Right atrium
• Right ventricle
• Left atrium
• Left ventricle

Question 10

How does the heart use its four chambers?

Answer 10

To pump blood around.

Question 11

How does the heart work?

Answer 11

• Blood flows into the two atria from the vena cava and the pulmonary vein.
• The atria contract, pushing the blood into the ventricles.
• The ventricles contract, forcing the blood into the pulmonary artery and the aorta, and out of the heart.
• The blood then flows to the organs through arteries and returns through veins.
• The atria fill again and the whole cycle starts over.