Cardiovascular Physiology: Exercise

Question 1

how to calculate fick equation

Answer 1

Q x a-vO2

Cardiac output x difference between arterial and venous O2

The difference is the amount delivered

Question 2

What is hyperemia

Answer 2

increased blood flow.

Question 3

During exercise what happens to flow, CO, BP, metabolism

Answer 3

Flow increases (hyperaemia)
-vasodilation to heart and skeletal muscle
CO increases
-both HR and SV increase
BP maintained or increases

Question 4

Active hyperaemia flowchart

Answer 4

metabolism increases -> release metabolic vasodilators (NO) ->arterioles dilate -> TPR decrease -> flow increases -> o2 and nutrient supply increases

process is to get more nutrients for higher metabolism

Question 5

What is the metabolic vasodilator

Answer 5

nitric oxide (nitroglycerin)

Question 6

What happens to the distribution of blood flow during exercise

Answer 6

flow to brain same

heart increases 5x

muscle increases 4x

viscera flow decreases

Question 7

what happens to BP during increasing intensity exercise

Answer 7

systolic increases linearly

diastolic remains constant

Question 8

what happens to variables on MAP = QxTPR during exercise

Answer 8

map and Q increase

TPR decrease

Question 9

What is afterload

Answer 9

force required to overcome TPR

Question 10

what happens to EDV and ESV during incremental exercise

Answer 10

EDV increases. ESV decreases.

more filling more emptying

Question 11

what is preload?

Answer 11

increased contractile force needed by heart to push greater vol of blood in ventricle due to more filling

Question 12

what is ejection fraction>

Answer 12

the PERCENT of blood that gets pumped out of heart.

SV/EDVx100

Question 13

what chronic cardiovascular adaptations occur to training

Answer 13

systolic and diastolic BP decrease at rest and sometimes submax exercise.

for hypertensive people, decrease at rest is more extensive and there is always a decrease for submax exercise

Question 14

How does the body allow very high BP during exercise

Answer 14

Central command: Feedforward data from brain to baroreceptors instruct them to adjust sensitivity range towards higher BP (up and to the right on the graph) .

Pressor reflex shifts the operating point of the baroreceptors. This is more optimal for controlling BP.

Question 15

what happens to BP and HR during lifting heavy weights.

Answer 15

HR increases a little but MAP dramatically increases. this causes a strong pressor load on the heart.

Question 16

what happens to BP during aerobic exercise

Answer 16

BP, systolic BP, SV increase proportionally. This causes more venous return and volume load on the heart.

Question 17

what heart adaptations can a resistance trained athlete acquire over time

Answer 17

left ventricle CONCENTRIC hypertrophy as a result of pressor overload. allows for more contractibility. This does not affect ventricular volume.

Question 18

what heart adaptations can an aerobic trained athlete acquire over time

Answer 18

left ventricular eccentric hypertrophy as a result of volume overload. This means that there is an increase in ventricular volume and some increase in left ventricle size and force.

Question 19

What adaptations can happen to the cardiovascular system for an aerobic athlete

Answer 19

SV, Q, and VO2 maxes increases. Blood vol also increases

B/c SV increases, HR decreases for the same Q as before (Q= SVxHR)

Question 20

Why does SV increase for a trained individual.

Answer 20

more filling, more emptying, more total L. ventricle vol, better EF

Question 21

how does SV change during incremental exercise (SV vs. VO2 graph)

Answer 21

it increases then plateaus

Question 22

what is the difference between physiological and pathological hypertrophy

Answer 22

their effects are similar but not the same.

Physiological hypertrophy is adaptive remodelling of the heart meaning the change assists the heart function. The thickening is proportional to the expansion of the cavity and the effect is completely reversible.

Pathological hypertrophy is a maladaptive remodelling of the heart. This means the adaptations impair heart function instead of improving it. The hypertrophy is primarily cell lengthening which creates longer and weaker cells. this effect is permanent.

Question 23

how can cardiac remodelling be a risk factor for athletes?

Answer 23

often the differences between maladaptive and adaptive hypertrophy and their effects overlap. This can obscure a potential life threatening issue.

Question 24

What are the most common CV related deaths in high performance athletes.

Answer 24

males: hypertrophic cardiomyopathy
females: congenital coronary artery anomalies

Males are 6.5 times more likely to suddenly die from CV diseases

Question 25

How much does Q increase during vigorous exercise for the untrained individual

Answer 25

4 times

Question 26

what is hematocrit

Answer 26

the percentage of RBC in a sample of blood. Average of 45%. Hydration can change the amount of plasma and therefore the percent of RBC per sample

Question 27

how to calculate total O2 content of a sample of blood

Answer 27

hemoglobin mass x 1.34ml x saturation /vol of blood

Question 28

how to calculate Vo2

Answer 28

fick equation /100ml

Question 29

What is a MET

Answer 29

1 MET = 3.5ml/kg/min

Question 30

Why is MET capacity important.

Answer 30

It can help determine a person’s longevity and risk of CV disease

increasing population MET capacity can reduce health costs