Heart./Exercise Physiology Review

Question 1

Diastole

Answer 1

Relaxation phase during which the ventricles fill with blood
AV valves open
Aortic and pulmonic valves closed

Question 2

Systole

Answer 2

Contraction phase during which ventricles expel blood
AV valves closed
Aortic and pulmonic valves open

Question 3

Intrinsic Control of the Cardiac Cycle

Answer 3

Autorythmaticity
Sinoatrial Node
Atrioventricular Node
Purkinje Fibers

Question 4

Authorhytmaticity

Answer 4

ability to initiate impulse for contraction at regular intervals

Question 5

Sinoatrial Node

Answer 5

Pacemaker of the heart

Question 6

Atrioventricular Node

Answer 6

Delays impulse by 1/10 of second, allowing atria to contract before ventricles

Question 7

Purkinje Fibers

Answer 7

Rapidly spread the impulse to contract throughout the ventricles

Question 8

P wave

Answer 8

atrial depolarization

Question 9

QRS complex

Answer 9

Ventricular depolarization and atrial repolarization

Question 10

T wave

Answer 10

ventricular repolarization

Question 11

Myocardial Ischemia

Answer 11

ST- segment depression

Question 12

Pressure During Diastole

Answer 12

Pressure is low

Atria fill with blood because the AV valves are open when the ventricular pressure is less than the atrial pressure

Question 13

Pressure During Systole

Answer 13

Pressure in ventricles rises and blood is ejected into the pulmonary and systemic circulation
Semilunar valves are open when ventricular P is greater than atrial P

Question 14

LUB sound

Answer 14

closing of the AV valves

Question 15

DUB sound

Answer 15

closing of the aortic and pulmonary valves

Question 16

Cardiac Output (Q)

Answer 16

= HR x SV

Question 17

Stroke Volume controlled by …

Answer 17

end diastolic volume, after load, contractility

Question 18

Extrinsic Regulation of Heart Rate

Answer 18

PNS via valgus nerve
SNS via cardiac accelerator nerves
Low resting HR dude to Parasympathetic tone
Increase in HR at onset of exercise

Question 19

Valgus Nerve

Answer 19

Slows HR by inhibiting SA and AV node

Question 20

Cardiac Accelerator Nerves

Answer 20

Increases HR by stimulating SA and AV Node

Question 21

Baroreceptors

Answer 21

carotid artery/ aortic arch
sense pressure changes by responding to changes in the tension of the ventricular wall I
If BP is high: send signal to medulla oblongata to increase PNA, decrese SNA, decrease HR (and SV, TPR) thus reduced BP

Question 22

Preload/EDV

Answer 22

volume of blood in the ventricles at the end of diastole

Question 23

Aortic BP/afterload

Answer 23

pressure the heart must pump against to eject blood (Mean Arterial Pressure)
The tension developed in the wall of the left ventricle during ejection

Question 24

Contractility

Answer 24

strength of the ventricular contraction

enhanced by circulating epinephrine and norepinephrine and also direct sympathetic stimulation of heart

Question 25

Frank-Starling Mechanism

Answer 25

Greater EDV results in a more forceful contraction (Due to stretch of ventricles) Dependent of venous return

Question 26

Increase venous return

Answer 26

Increase by venoconstriction, skeletal muscle pump and respiratory pump,

Question 27

Skeletal Muscle Pump

Answer 27

rhythmic skeletal muscle contractions force blood in the extremities toward the heart one-way valves in veins prevent backflow of blood

Question 28

Respiratory Pump

Answer 28

changes in thoracic pressure pull blood toward the heart

Question 29

High afterload

Answer 29

decrease in stroke volume, requires greater force generation by the myocardium to eject blood into the aorta

Question 30

Increased contractility

Answer 30

results in higher stroke volume - circulating epinephrine and norepinephrine - direct sympathetic stimulation of the heart

Question 31

Increase Stroke Volume

Answer 31

Increase EDV Decrease Afterload Increase Contractility

Question 32

Determinants of mean arterial pressure

Answer 32

cardiac output, total vascular resistance ( TVR or TPR) | ABP= CO xTPR

Question 33

Short term regulation of ABP

Answer 33

sympathetic nervous system to heart and vasculature baroreceptors in aorta and carotid arteries increase in BP= decrease SNS activity= Normal BP decreased BP =increased SNS activity=normal BP

Question 34

Long term regulation of BP

Answer 34

kidneys via the blood volume control

Question 35

TPR

Answer 35

regulated by vasodilation or vasoconstriction

Question 36

vasodilation

Answer 36

decreased resistance, decreased BP | nitric oxide

Question 37

vasoconstriction

Answer 37

increased resistance, increased BP | Norepinephrine

Question 38

Blood pressure eqx

Answer 38

BP= Q x TPR

Question 39

To increase HR

Answer 39

increase SNA | Decrease PNA

Question 40

Increase TPR

Answer 40

Increase SNA and Decrease the radius