8.5

Question 1

what is the heart made up of?

Answer 1

cardiac muscle

Question 2

what provides the cardiac muscles with oxygen?

Answer 2

coronary arteries

Question 3

what are the four chambers of the heart?

Answer 3

left atrium
left ventricle
right atrium
right ventricle

Question 4

what are the semi-lunar valves?

Answer 4

valves found at the pulmonary artery and aorta which prevent blood from re-entering the ventricles

Question 5

what are the atrioventricular valves?

Answer 5

valves found between the atrium and ventricles which prevents backflow of blood into the atrium

Question 6

what is the septum?

Answer 6

inner dividing wall which prevents oxygenated and deoxygenated blood from mixing

Question 7

why is the left side of the heart have a thicker muscular wall?

Answer 7

in order to sufficiently pump blood through the aorta at a high pressure to the rest of the body

Question 8

what is diastole?

Answer 8

relaxing of the muscles

Question 9

what is systole?

Answer 9

contracting of the muscles

Question 10

what causes the lub sound?

Answer 10

closing of the atrioventricular valves

Question 11

what causes dub sound?

Answer 11

closing of the semi-lunar valves

Question 12

why is the cardiac muscle myogenic?

Answer 12

it has it’s own heart rythm

Question 13

how is the heart stimulated?

Answer 13

the SAN send a wave of excitation to the atrial muscles causing atrial systole

this wave is picked up by the AVN which delays the wave before sending it down the bundle of His towards the apex

at the apex the wave is passed to the ventricular muscles which contract causing ventricular systole

Question 14

what does the delay at the AVN ensure?

Answer 14

that the atria have stopped contracting before the ventricles start

Question 15

what measures electrical excitation?

Answer 15

an electrocardiogram
ECG

Question 16

what is the PQRST wave?

Answer 16

Question 17

P wave

Answer 17

atrial systole

Question 18

QRS wave

Answer 18

ventricular systole

Question 19

T wave

Answer 19

ventricular diastole

Question 20

what is tachycardia?

Answer 20

when the heartbeat is too rapid

Question 21

what is bradychardia?

Answer 21

when the heartbeat is too slow

Question 22

what is ectopic heartbeat?

Answer 22

extra heartbeats which are out of rhythm

Question 23

what is atrial fibrillation?

Answer 23

abnormal rhythm of the heartbeat which results in short systole and blood not being pumped properly

the p wave is messed up

Question 24

what is the order of events in one pump of the heart?

Answer 24

atrial systole
atrial diastole
ventricular systole
ventricular diastole

Question 25

when do AV valves open?

Answer 25

when the pressure in atria is greater than ventricles

Question 26

hen do AV valves close?

Answer 26

when the pressure in the ventricles is greater than the atria

Question 27

when do the semi-lunar valves open?

Answer 27

when the pressure in the ventricles is greater than pressure in the aorta

Question 28

when do the semi-lunar valves close?

Answer 28

when the pressure in the aorta is greater than pressure in the ventricles

Question 29

atrial systole

Answer 29

walls of atria contract and force blood into the ventricles the atrio-ventricular valves are opened ventricular pressure begins to rise

Question 30

ventricular systole

Answer 30

when ventricular pressure exceeds atrial pressure the atrio-ventricular valves close semi-lunar valves open when ventricular pressure exceeds aortic pressure ventricular muscles contract, forcing blood to be pushed into aorta

Question 31

what is the cardiac output?

Answer 31

volume of blood pumped through the heart per minute

Question 32

cardiac output equation

Answer 32

heart rate x stroke volume

Question 33

what is the heart rate?

Answer 33

beats per minute bpm

Question 34

what is the stroke volume?

Answer 34

volume of blood pumped in each heartbeat cm3