Exercise Physio

Question 1

Type I Muscle

Answer 1

Slow twitch

oxidative aerobic metabolism

fatigue resistance

red - rich in mitochondria

Question 2

Type IIB muscle

Answer 2

fast twitch

glycolytic anaerobic metabolis

fatiguable

white

Question 3

Type II A

Answer 3

intermediate between I and IIB, oxidative and glycolytic metabolism

Question 4

increased muscle demand for oxygenated blood during exercise

Answer 4

working muscle increase extraction

shunting from nonworking muscles - vasoconstriction

increase CO (increase HR by a lot! And SV)

Question 5

Effect of exercise on TPR

Answer 5

as CO and oxygen uptake increases, TPR decreases

Question 6

SBP and DBP response to exercise

Answer 6

systolic pressure increses! diastolic blood pressure usually stays the same

Question 7

HR in trained vs untrained athletes

Answer 7

trained = lower rise in HR

untrained = HR rises faster

Question 8

stroke volume in trained vs untrained

Answer 8

higher resting and peak SV in trained athletes

Question 9

Can the heart extract more oxygen with exercise?

Answer 9

no

unlike peripheral muscle, myocytes are always extracting at near max levels

increases in cardiac cell oxygen deman during increasing work are met entirely by increasing cardiac output!!

Question 10

Oxygen consumption equation

Answer 10

V(O2) = CO x A-V O2 difference

related to work, estimated by intensity for work

Question 11

V(O2) max

Answer 11

max CO x A-V O2 difference

Question 12

changing oxygen extraction

Answer 12

don’t know how

don’t change it everywhere - regional response

no increase in untrained - training is a peripheral effect not a heart effect!!

Question 13

Overcoming checks on HR

Answer 13

Increase in HR suppressed at rest by PNS

SNS input to SA node increases HR - more sympathetic tone in peak exercise (switch)

resets arterial baroreflex operating point to control heart rate - so doesn’t compensate for increased BP

Question 14

E Phys vs prolonged standing

Answer 14

standing - CO falls then compensatory increased CO , fall in parasym and rise in sym

unlike exercise (peripheral vasodilation) there is a peripheral vasoconstriction

Question 15

effects of pregnancy on the heart

Answer 15

CO rises (HR x SV) and peropheral resistance falls (like exercise)

blood volume increases

CO increases (at first due to SV, later to HR)

BP - falls with SFR)

Question 16

Echocardiography in pregnancy

Answer 16

cadiac dilation (most on right side but everywhere)
small pericardial effusion

dilation of valves can lead to regurgitation