The Circulatory system - heart and circulation system

Question 1

role of arteries

Answer 1

• arteries carry blood away from the heart at high pressure
• they carry oxygenated blood APART FROM THE PULMONARY ARTERY
• thick muscular walls
• narrow lumen to maintain high pressure
• speed of flow is fast

Question 2

role of veins

Answer 2

• veins carry blood back to the heart at low pressure
• they carry deoxygenated blood APART FROM THE PULMONARY VEIN
• thin walls
• large lumen
• speed of flow is slow

Question 3

heart

Answer 3

• four chambered
• double circulation
• for every one circuit of the body, the blood passes through the heart twice
• ventricles have thicker muscle walls than the atria because they are pumping blood out of the heart so need higher pressure

Question 4

right side of the heart

Answer 4

• receives deoxygenated blood from the body and pumps it to the lungs
• thinner muscle wall than the left ventricle as it is pumping blood at a lower pressure to the lungs

Question 5

blood journey on the right side of the heart

Answer 5

• comes from body (deoxygenated blood)
• flows into the right atrium via the vena cava
• pushed through the tricuspid valve into the right ventricle
• walls of the ventricle contract and blood is pushed into the pulmonary artery through the semi lunar (pulmonary) valve

Question 6

left side of the heart

Answer 6

• receives oxygenated blood from the lungs and pumps it to the body
• left ventricle has a thicker muscle wall than the right ventricle because it has to pump blood at a high pressure around the body

Question 7

blood journey on the left side of the heart

Answer 7

• comes from lungs ( oxygenated blood)
• flows into the left atrium via the pulmonary vein
• passes through the bicuspid valve into the left ventricle
• thicker muscle walls of the ventricle contract strongly to push blood into the aorta through the semi lunar (aortic) valve and all around the body

Question 8

function of valves

Answer 8

to prevent blood flowing backwards

Question 9

valves

Answer 9

• valve on the right side of the heart is the tricuspid

- valve on the left side of the heart is called the bicuspid

Question 10

What increases the risk of coronary heart disease?

Answer 10

• coronary arteries supply blood, oxygen, glucose and other nutrients to the heart
• coronary arteries can become partially or completely blocked about fatty deposits called ‘plaques’, cells in that area of the heart will not be able to respire and can no longer contract
• leads to a heart attack

Question 11

causes of coronary heart disease

Answer 11

• poor diet
• stress
• smoking

Question 12

role of capillaries

Answer 12

• carry blood at low pressure within tissues
• carry both oxygenated and deoxygenated blood
• have walls that are one cell thick for easy diffusion
• speed of flow is slow