the cardiovascular system

Question 1

control for ghost shrimp/ daphnia experiment

Answer 1

plain water/ solvent used for caffeine solution
to compare with the caffeine solutions to show normal/ resting HR
temperature of solution- cold temp would decrease HR
same size/ sex/ age of shrimp - so caffeine would affect ghost shrimp equally

Question 2

medication to reduce BP

Answer 2

antihypertensives

Question 3

explain why a mammal with a hole between two ventricles will experience tiredness

Answer 3

less oxygen available for aerobic respiration
deoxy blood mixes with oxy blood
reduces conc of oxygen in blood circulating the body
some deoxy blood does not leave right ventricle/ is transferred to left ventricle/ does not go to lungs/ goes to respiring tissues

Question 4

type of blood vessel with no collagen in its wall

Answer 4

capillary

Question 5

devise investigation for daphnia

Answer 5

daphnia immobilised on cavity slide
acclimatisation time in control/ water solution and caffeine solution- 1 minute
observe under microscope and count heart beat for 15 seconds
use daphnia of same sex/age/ species/ size
repeats and calculate mean and standard deviation

Question 6

explain how pressure differences in heart ensure efficient pumping of blood into arteries

Answer 6

pressure increases in the ventricles
greater pressure in the ventricles than in the atria
causing atrioventricular valves to close
causing the semi lunar valves to open/ forcing blood into the arteries

Question 7

explain how changes in blood pressure occur in the cardiac cycle in ventricles

Answer 7

pressure increases due to atrial systole
ventricles fill with blood from atrium
after atrial systole finishes there is a fall in ventricular pressure
increase in pressure due to ventricular systole
ventricular pressure decreases due to ventricular diastole