Exercise Pathology: Acute and Training CV changes

Question 1

How do you increase cardiac output?

Answer 1

Increase HR, increase SV

Question 2

How can ventilation be increased?

Answer 2

Increase frequency of breathing, increase tidal volume

Question 3

Determine dynamic exercise?

Answer 3

by 02 consumption, V02 is the metabollic rate, determined by tissues

Question 4

Cardiac output?

Answer 4

Q

Question 5

Circulatory changes?

Answer 5

a-v 02 difference

Question 6

Increase HR?

Answer 6

decreased parasympathetic tone initially, increased sympathetic tone in heavy exercise

Question 7

Sv is increased by?

Answer 7

increased end diastolic volume (preload), increased sympathetic activation (contractility)

Question 8

Increased cardiac output is related to HR and SV?

Answer 8

HR increases linearly with increased work load but SV rises rapidly with increased work load

Question 9

SV=?

Answer 9

EDV-ESV
decrease SV from increased ESV or decreased EDV

increase SV from decrease ESV or increase EDV

Question 10

influence ESV?

Answer 10

afterload, contractility

Question 11

influence EDV?

Answer 11

Stiffness, HR, preload

Question 12

Increase venous return?

Answer 12

muscle pump (displaces blood form peripheral veins to central veins)

respiratory pump (increase intrathoracic pressure sucks blood into heart, neg pressure in chest becomes more negative draw blood in)

by increasing venous return, increase filling pressure and EDV

Question 13

Muscle 02 extraction increases in exercise?

Answer 13

increase in arterial-venous 02 difference, increase muscle 02 extraction, systemic redistribution of blood, vasodilation and capillary recruitment increase in active muscle

Question 14

Blood distribuition and redistribution in excercise, decrease most? increase most?

Answer 14

decrease- splanchnic normally 24%, 1%

increase- skeletal m 21%, 86%

Question 15

How does blood redistribute in exercise?

Answer 15

via vasoconstriction of blood vessels under alpha 1 receptors
allow less blood in inactive muscle, splanchnic circulation, renal circulation, cutaneous circulation

Question 16

Rate of diffusion law?

Answer 16

Fick’s law

Question 17

MAP and TPR during exercise?

Answer 17

because of vasodilation, TPR decreases and BP only increases slightly

Question 18

BP change in static vs dynamic?

Answer 18

static- increases greatly because less influence of vasodilation in static exercise

dynamic- increase and then decrease

Question 19

Metaboreceptors?

Answer 19

muscle receptor, sensitive to metabolic environment, group IV sensory afferents, can cause large increase in SNS outflow

Question 20

Mechanoreceptors?

Answer 20

muscle receptor, sense mechanical environment, group III sensory afferent

Question 21

Baroreceptors?

Answer 21

they reset during exercise to a higher BP, become less potent, reducing HR when BP increased

Question 22

V02?

Answer 22

oxygen consumption, increases linearly with work rate up to V02max

increased ventillation, increased cardiac output, increased muscle 02 extraction

Question 23

Main limitation of V02max?

Answer 23

cardiac output, as maximim cardiac output (Q) increases, V02max incrases

Question 24

When does the lung limit V02max?

Answer 24

in athletes during severe exercise
exercise induced arterial hypoxemia
can be overcome by breathing higher 02
excessive respiratory muscle work consumes some of the V02

Question 25

how does training improve V02max?

Answer 25

O2 extraction depends on ability of diffusion from capillary to mitochondria, training increases muscle diffuse capacity, increasing v02max

Question 26

Muscle fatigue limits exercise performance?

Answer 26

onset of fatigue
 fiber type
 accumulation of K, lactate
 reduction of pH
 depletion of glycogen, PCr

Question 27

What does performance rely on in addition to V02max?

Answer 27

mechanical efficiency

edurance at high V02 rates, anaerobic threshold

Question 28

Women to get same power output do what?

Answer 28

work at a higher % of V02 max, at occurs at decreased power outputs in women

Question 29

Why can someone run longer?

Answer 29

they have a higher anaerobic threshold, regardless if they have the same V02max

Question 30

How can you increase V02max?

Answer 30

training will increase it, increase resistance to fatigue due to increased lactate threshold

respiratory system is mostly unchanged by training

Question 31

CV changes from training?

Answer 31

maximal cardiac output increase, resting HR lower but max is unchanged, max SV increases, modest reduction in BP