Heart And Circulation

Question 1

Where are the atriums

Answer 1

At the top of the heart

Question 2

Vena cava function

Answer 2

Brings in deoxygenated blood from the body

Question 3

Pulmonary vein function

Answer 3

Oxygenated blood passes from lungs to heart in the vein

Question 4

Aorta function

Answer 4

Oxygenated blood pumped from heart to body in aorta

Question 5

Why does left side have thicker muscle

Answer 5

Pumps blood around whole body
= requires more force

Question 6

Coronary arteries function

Answer 6

Provide oxygen to muscle cells of the heart
= oxygen used in respiration to provide energy for contraction

Question 7

Pacemaker function

Answer 7

Control natural resting heart rate

Question 8

Describe an artificial pacemaker

Answer 8

Small electrical device to correct irregularities in the heart rate

Question 9

Adaptations of arteries

Answer 9

Thick muscular walls
= withstand very high blood pressure of blood
Contains elastic fibres
= stretch when surge of blood passes through and then recoil in between surges
= keeps blood moving

Question 10

What happens in capillaries

Answer 10

Blood passes through
Substances like glucose and oxygen diffuse from blood to the cells

Question 11

Adaptations of capillaries

Answer 11

Very thin walls
= very short diffusion path
= allow substances to diffuse rapidly between blood and body cells

Question 12

Adaptations of veins

Answer 12

Thin wall
= low blood pressure so doesn’t need to be thick
Contain valves
= prevent blood back flow

Question 13

Effects of leaky valve

Answer 13

• backflow can occur
• less blood leaves heart
• less oxygen to muscles
  = less aerobic respiration
  = less energy released
  = less efficient muscle contraction
• anaerobic respiration
  = less efficient removal of lactic acid
  = cause muscles to fatigue
  = less efficient co2 removal