Circulatory system - the heart

Question 1

What are the three parts of the circulatory system?

Answer 1

• Blood
• Blood vessels
• Heart

Question 2

What is the function of the circulatory system?

Answer 2

• Carries food and oxygen to every cell in the body
• Transports waste substances to where they can be disposed of

Question 3

Why is it often called the double circulatory system?

Answer 3

• There are 2 circuits joined together to form the heart
• Circuit 1 - carries deoxygenated blood to the lungs and returns with oxyenated blood
• Circuit 2 - carries oxygenated blood to the rest of the body and returns with deoxygenated blood

Question 4

How does the heart work?

Answer 4

• Blood enteres the heart via the pulmonary vein (oxygenated blood from the lugs) and the vena cava (deoxygenated blood from around the body) and fills the left atrium (pulmonary vein) and the right atrium (vena cava)
• The atria contract, forcing the blood into the ventricles
• The ventricles contract, forcing the blood out of the heart via the pulmonary artery (towards lungs) and aorta (around the body)

Question 5

Why does the heart have valves?

Answer 5

• To prevent backflow

Question 6

What is the pacemaker and where is it?

Answer 6

• The pacemaker is a group of cells in the right atrium
• Sends electrical impulses causing the heart uscles to contract

Question 7

What happenes when the pacemaker stops working?

Answer 7

• An artificial pacemaker is imlanted under the skin

Question 8

How does the heart get its required oxygen?

Answer 8

• Oxygen for the heart is provided by coronary arteries which branc off from the aorta and encapsulate the heart