Cardiovascular System and Response to Exercise

Question 1

End Diastolic Volume

Answer 1

Amount of blood in ventricle at end of ventricular filling

As EDV goes up, better ventricular performance

Question 2

End Systolic Volume

Answer 2

Amount of blood left in ventricles after systole

Question 3

Preload

Answer 3

Amount of blood coming into/getting back to heart

Increased in supine

Question 4

Afterload

Answer 4

What pressure ventricle senses when it contracts

Increased with HTN

Question 5

Contractility

Answer 5

Extent of squeeze

Increases with activity

Question 6

Frank-Starling Mechanism

Answer 6

More blood in ventricles cause greater stretch

Contract with increased force

Question 7

Metabolic-CV-Ventilatory Coupling

Answer 7

1. PA causes increase in O2 demand/CO2 production at cellular level
2. Peripheral circulation dilates
3. CV system increases SV and HR
4. Pulmonary system recruited to increase tidal volume and breathing frequency

Question 8

Cardiac Cycle

Answer 8

Events between 2 heart beats/systole to systole/R wave to R wave
Lasts .9 seconds with HR of 67 bpm

Question 9

Diastole

Answer 9

Relaxation
Low pressure
Ventricles fill with blood
T to QRS

Question 10

Systole

Answer 10

Contraction or “squeeze”
Ventricles expel blood
QRS to T

Question 11

Diastole Function

Answer 11

Ventricular filling
Rapid filling due to pressure difference
Final filling - atrial contraction

Question 12

Systole Function

Answer 12

Isovolumetric contraction - all valves close and close ventricle begins to contract
Ejection phase - outlet valves open
Isovolumetric relaxation - all valves close and pressure falls rapidly

Question 13

Parasympathetic NS

Answer 13

Vagus
SA Node - causes depolarization
In control at rest
Light to moderate PA

Question 14

Sympathetic NS

Answer 14

Epinephrine and Norepinephrine - increased myocardial contractility and blood flow
Near max and max effort

Question 15

Cardiac Regulation

Answer 15

Done by SA node
AV can pace, but slower than SA
AV passes information to bundle of HIS and Purkinje fibers

Question 16

Maximal Oxygen Consumption

Answer 16

Measure of CRF

VO2 Max = SV*HR (Q) * arteriovenous oxygen difference

Question 17

AVO2 Difference

Answer 17

How much oxygen is in arterial system versus how much is left in venous system

Question 18

Cardiac Output

Answer 18

Amount of blood pumped out of heart per unit of time

Question 19

Stroke Volume

Answer 19

Amount of blood pumped by left ventricle with one contraction
EDV-ESV
Increases curvilinearly with work rate until it reach near max (about 50% of aerobic capacity)

Question 20

HR (resting)

Answer 20

Averages 60-80 bpm
Range from 30 bpm to 100 bpm
Can decrease with age (abnormal) but likely to increase due to decreased parasympathetic control
Affected by environmental conditions

Question 21

HR (max)

Answer 21

HR achieved by all-out effort

220-age

Question 22

HR (steady state)

Answer 22

Plateau reaching during constant rate of submit work

Lower steady-state, more efficient the heart

Question 23

HR and Intensity

Answer 23

Increase linearly

Question 24

HR and Training

Answer 24

HR goes down with training due to maximizing stroke volume

Question 25

HR during Submax loads

Answer 25

HR decreases proportionately with amount of training complete

Question 26

HR during Max effort

Answer 26

Remanges unchanged or decreases slightly

Decrease may allow optimal stroke volume