PHYSIOLOGY OF THE HEART

Question 1

What are the 2 systems that control the functions of the heart?

Answer 1

autonomic nervous system and intrinsic conduction system

Question 2

decrease or increase the heart rate depending on which division is activated

Answer 2

Autonomic Nervous System

Question 3

cardiac muscles contracts spontaneously and independently of nerve impulses

Answer 3

Intrinsic Conduction System

Question 4

Normal Heart Rate

Answer 4

75 bpm

Question 5

atrial cells beat ___ times per minute

Answer 5

60

Question 6

ventricular cells beat ___ times per minute

Answer 6

20-40

Question 7

starts each heartbeat; “Pacemaker of the heart”

Answer 7

Sinoatrial Node (SA)

Question 8

True or false: The impulse is somewhat delayed to give thenatria ample time to finish contracting

Answer 8

True

Question 9

rapid heart rate, over 100 beats per minute

Answer 9

Tachycardia

Question 10

slow heart rate, less than 60 beats per minute

Answer 10

Bradycardia

Question 11

one complete heartbeat, in which both atria and ventricles contract and then relax

Answer 11

Cardiac cycle

Question 12

contraction; represents the time during which the left and right ventricles contract and eject blood in the aorta and pulmonary artery respectively

Answer 12

Systole

Question 13

period of relaxation; where the muscles are relaxed

Answer 13

Diastole

Question 14

Cardiac cycle length is about

Answer 14

0.8 seconds

Question 15

First event of the card cycle where the heart is relaxed, pressure is low and the av valves are open, allowing blood to flow into the atria

Answer 15

Atrial diastole

Question 16

The atria contracts allowing blood to completely fill the ventricles

Answer 16

Atrial systole

Question 17

Atrial systole ends; ventricular systole begins
And the av valves close

Answer 17

Isovolumetric contraction

Question 18

Semilunar valves open and blood is ejected from the ventricles

Answer 18

Ventricular systole

Question 19

Pressure falls below that in the major arteries, semilunar valves close and for another moment, the ventricles are completely closed chambers

Answer 19

Isovolumetric relaxation

Question 20

longer, louder heart sound caused by the closing of the AV valves

Answer 20

Lub

Question 21

short, sharp heart sound caused by the closing of the semilunar valves at the end of the ventricular systole

Answer 21

Dup

Question 22

amount of blood pumped by each side (ventricle) of the heart in 1 minute

Answer 22

Cardiac output

Question 23

volume of blood pumped by each ventricle in one contraction (each heartbeat)

Answer 23

Stroke volume

Question 24

How much ml of blood is pumped out of the left ventricle with each heartbeat?

Answer 24

70 ml

Question 25

Formula for cardiac output

Answer 25

Heart Rate x stroke volume

Question 26

The more the cardiac muscle is stretched, the stronger the contraction

Answer 26

Starling’s Law of the Heart

Question 27

is the important factor influencing the stretch of heart muscle

Answer 27

Venous return

Question 28

Sympathetic nervous system speed heart rate

Answer 28

Neural (ANS) Controls

Question 29

True or false: hormones like epinephrine and thyroxine influence heart rate

Answer 29

True

Question 30

True or false: Age, gender, exercise, body temperature do not influence heart rate

Answer 30

False