Topic 4 - Circulation

Question 1

What is the structure of an artery

Answer 1

Thick lumen - protection
Thick middle layer of elastic and muscle tissue - constrict of relax to increase or decrease blood supply
Endothelium - reduce friction caused by blood
Lumen - thin to maintain blood pressue

Question 2

What is the structure of a capillary

Answer 2

Squamous endothelium- thin to provide short diffusion distance
Small lumen - slower blood flow to facilitate diffusion

Question 3

What is the structure of a vein

Answer 3

Thick outer layer - protection
Thin middle layer of mainly elastic tissue - low pressure
Endothelium - reduce friction causes by blood
Large lumen - easier for blood to enter heart
Valves - prevent backflow

Question 4

What is atrial systole

Answer 4

Atria contract
Blood pushed into ventricles

Question 5

What is ventricular systole (a)

Answer 5

Ventricular pressure increases
Pushes AV valves intro atria increasing pressure
Chordae tendinae prevents AV valves turning inside out

Question 6

What is ventricular systole (b)

Answer 6

Ventricular pressure increases
Exceeds surrounding arteries , pushing semi lunar valves open
Blood flows into atria
Atrial pressure increases

Question 7

What is diastole (a)

Answer 7

Ventricular pressure drops
Semilunar valves shut
Blood cannot ventricles
AV valves remain closed

Question 8

What is diastole (b)

Answer 8

Ventricular pressure drops
AV valves open
Blood enters ventricles from atria

Question 9

What is myoglobin

Answer 9

A conjugated protein of 1 polypeptide and 1 haem group

Question 10

What is the function of myoglobin

Answer 10

Acts as an energy storage
Myoglobin only gives up its oxygen when partial pressure of oxygen becomes very low
Delays the onset of anaerobic respiration