Lifestyle Health And Risk

Question 1

Define mass flow

Answer 1

Movement of particles in a liquid in one direction through tubes due to difference in pressure (created by the heart)

Question 2

What happens to rate of diffusion as surface area : volume ratio decreases

Answer 2

Decreases

Question 3

What are the three stages of the cardiac cycle

Answer 3

1. Atrial systole
2. Ventricle systole
3. Cardiac diastole

Question 4

What happens during atrial stystole

Answer 4

Atria fill with blood and contract together - chamber volume decreases - pressure increases so AV valves open - blood forced out into ventricles which are relaxed

Question 5

What happens during ventricular systole

Answer 5

Slight delay then ventricles contract from bottom up and the high pressure forces the AV valves shut and SL valves open

Question 6

What happens during cardiac diastole

Answer 6

Higher pressure in aorta forces the SL valves shut to prevent back flow
Elastic recoil of atria walls lowers pressure to draw blood back in