Cardiovascular System Physiology of the Heart

Question 1

two phases of the heartbeat

Answer 1

diastole and systole

Question 2

diastole

Answer 2

relaxation phase of the heartbeat (ventricle walls relax and blood flows into the heart from the venae cavity and the pulmonary veins)

Question 3

systole

Answer 3

contraction phase of the heartbeat (walls of the right and left ventricles contract to pump blood into the pulmonary artery and aorta. Both the tricuspid and mitral valves are closed during systole, thus preventing the flow of blood back into the atria

Question 4

which valves open in diastole

Answer 4

tricuspid and mitral valve open as blood passes from the right and left atria into the ventricles.

Question 5

which valves close at the beginning of diastole

Answer 5

pulmonary and aortic valves

Question 6

diastole-systole cardiac cycle

Answer 6

occurs between 70-80 times per minute (100,000 times a day) pumps 3 oz of blood with each contraction (5 quarts of blood are pumped by the heart in 1 minute (75 gallons an hour and about 2000 gallons a day)

Question 7

murmur

Answer 7

abnormal swishing sound caused by improper closure of the heart valves

Question 8

lubb-dubb

Answer 8

closure of the heart valves associated with this audible sound

Question 9

lubb

Answer 9

associated with the closure of the tricuspid and mitral valves at the beginning of systole (first heart sound (S1))

Question 10

dubb

Answer 10

associated with the closure of the aortic and pulmonary valves at the end of systole (second heart sound (S2))

Question 11

sinoatrial nerve (SA node)

Answer 11

pacemaker of the heart

Question 12

pacemaker (sinoatrial nerve)

Answer 12

specialized nervous tissue in the right atrium that begins the heartbeat.

Question 13

what does the current of electricity generated by the peacemaker do?

Answer 13

causes the walls of the atria to contract and force blood into the ventricles

Question 14

atrioventricular node (AV node)

Answer 14

specialized tissue in the wall of the atria. Electrical impulses pass form the pacemaker (SA node) through the AV node and the atrioventricular bundle of His toward the ventricles

Question 15

atrioventricular bundle (bundle of His)

Answer 15

specialized muscle fibers connecting the atria with the ventricles and transmitting electrical impulses between them. divides into left bundle branch and right bundle branch

Question 16

electrocardiogram

Answer 16

record used to detect these electrical changes in heart muscle as the heartbeats

Question 17

defelections

Answer 17

5 waves that represent the electrical changes as a wave of excitation spreads through the heart

Question 18

normal sinus rhythm

Answer 18

heart rhythm originating in the sinoatrial node with a rate in patients at rest of 60 to 100 beats per minute