cardiac cycle

Question 1

1:blood enters atria

Answer 1

via vena cava and pulmonary vein

Question 2

2:atrial systole

Answer 2

atrium walls contract and pressure pushes blood through the av valves to ventricles down a concentration gradient
pressure increases and volume decreases in atria

Question 3

3:ventricular systole

Answer 3

ventricle walls contract and increase pressure so blood leaves through sl valves as av valves slam shut

Question 4

4:blood leaves

Answer 4

blood leaves through aorta and pulmonary artery

Question 5

diastole

Answer 5

ventricles relax=pressure decreases
valves shut to stop ventricle backflow
atria relax, cycle repeats

Question 6

rise and fall of cardiac cycle felt as

Answer 6

pulse

Question 7

step by step blood flow in left side of the heart

Answer 7

1. left atrium relaxes and receives oxygenated blood from PV
   2.bicuspid valve opens and left ventricle relaxes and takes blood
   3.left atrium contracts for ALL the blood to leave
   4.left atrium relaxes, left ventricle contracts
   5.blood leaves through semilunar valves into aorta and the bicuspid valve closes

Question 8

ecg

Answer 8

electrocardiogram
trace of voltage changes in the heart

Question 9

p wave

Answer 9

small waves generated by the san, atrial contraction
atria have less muscle and blood goes gravitationally so is a small hump

Question 10

qrs complex

Answer 10

ventricles have more muscle so amplitude is higher
depolarisation and contraction of ventricles

Question 11

depolarisation

Answer 11

wave of ions moving across membranes that releases energy for contraction

Question 12

PR interval

Answer 12

time for wave of excitation to reach ventricles through avn

Question 13

t wave

Answer 13

repolarisation of the ventricles
the heart muscles rest and recharge themselves by restoring electrical balance

Question 14

isoelectric line

Answer 14

line that goes from end of one t to the next p wave/start of the new cycle