module 3: the heart

Question 1

which side of the heart is thicker

Answer 1

left

Question 2

what does the right side do

Answer 2

pump deoxygenated blood to the lungs

Question 3

what does the left side do

Answer 3

pump oxygenated blood to the body

Question 4

atrioventricular valves

Answer 4

link atria to ventricles

Question 5

semi lunar valves

Answer 5

link ventricles to pulmonary artery and aorta

Question 6

step 1 of cardiac cycle

Answer 6

atrial systole
ventricles relax and atria contract, blood pumped to ventricles through av valves

Question 7

step 2 of cardiac cycle

Answer 7

ventricular systole
atria relax and ventricles contract
av valves shut and sl valves open
blood flows to pulmonary artery and aorta

Question 8

step 3 of cardiac cycle

Answer 8

ventricular diastole
ventricles and atria relax
sl valves closed av valves open
atria fill with blood and passive flow to ventricles

Question 9

cardiac output

Answer 9

heart rate x stroke volume

Question 10

how is a heart beat initiated

Answer 10

heart is myogenic
1- sino atrial node send save of excitation to atrial walls so atria contract
2- band of fibres prevent direct passing of wave to to ventricles for a slight delay
3- wave passes to atrioventricular node
4- this then passes wave to the bundle of His and to the purine fibres in the walls of the ventricles making them contract

Question 11

heart beats too fast

Answer 11

tachicardia- 120 bpm

Question 12

heart beat to slow

Answer 12

brachicardia- 60bpm

Question 13

ectopic heartbeat

Answer 13

early contraction of the atria

Question 14

irregular heartbeat

Answer 14

fibrillation, rhythm lost in heart so stops contracting properly

Question 15

what records heart activity

Answer 15

electrocardiograph
p wave- atria contract
qrs complex- ventricles contract
t wave- relaxation of ventricles