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SPEX303 FINAL EXAM LATEST ACTUAL
EXAm QUESTIONS AND CORRECT
DETAILED ANSWERS
Why is BP important for physiological function? - (ANSWER)Ensures adequate
perfusion of tissues which is essential for blood to circulate to all the places it
should go
How does BP respond acutely to exercise and why does response depend on
intensity? - (ANSWER)Rises during static exercise, response depends on intensity
because blood pressure increase as cardiac output does to increased oxygen
demand from the working muscles.
How does cardiac output change during dynamic exercise and how is blood flow
distributed to different tissues during exercise? - (ANSWER)5-8 fold increase in
cardiac output. During exercise, blood flow to the GI tract and kidneys is reduced
but blood flow to the muscles increases as well to the brain slightly but the
change is a large relative decrease.
What factors control regional blood flow to tissues like the brain, muscles and
skin during exercise - (ANSWER)SNS nerves and receptors, myogenic
autoregulation specifically to the brain and kidney and metabolic auto regulation
such as temperature, pH, CO2 and ATP in the striated muscle
What role do local factors such as nitric oxide and metabolic byproducts play in
controlling blood flow to active muscles? - (ANSWER)NO released from muscle,
RBC's and endotheialil cells. NO promotes vasodilation with the released
mediated by mechanical stress on the blood vessel walls and hypoxia. Because NO
, 2
causes relaxation of the smooth muscle it leads to vasodilation which allow for
increased blood flow to active muscle due to decreased vascular resistance. CO
leads to localised vasodilation and ATP redistribute blood flow by stimulating SNS
meaning the heart beats faster and shuts down inactive muscle allowing for more
blood to be distributed to working muscles
How does blood volume typically change during acute exercise? -
(ANSWER)Commonly decreases at onset and within a few days it rises due to
stress hormones and depending on posture in hours post exercise.
What are the primary causes of acute plasma volume reduction in exercise? -
(ANSWER)Sweating which means fluid is lost decreasing plasma volume and fluid
lost into interstitial space due to decrease in capillary permeability which allows
fluid to leak through blood vessels into surrounding tissue
What are the primary determinant of stroke volume during exercise and how do
factored like preload and after load infueluce it? - (ANSWER)Preload, afterload
and contractility. Preload influences it as it determines the stretch of the heart
muscle fibers before contraction, a higher stroke volume is experienced as the
heart stretches with increased blood volume which generates a stronger
contraction. Afterload influences it as reduced afterload during aerobic exercise
enhances stroke volume as vasodilation in active muscles decreases systemic
vascular resistance.
How does heart rate respond to increasing exercise intensity, and what role do
the sympathetic and parasympathetic nervous systems play in this response? -
(ANSWER)Heart rate rises with increasing exercise intensity, but those trained
have a lower HR at any given intensity. At low to moderate intensity, HR increases
quickly due to withdrawal of the PNS and slight activation of SNS. At moderate to
, 3
high intensity HR continues to rise due to greater activation of the SNS, at
moderate intensities stroke volume plateaus so further increases in cardiac
output rely primarily on heart rate. At rest the PNS helps to keep heart rate low
but at the onset of exercise, it is withdrawn. The SNS takes over at moderate to
high intensities to stimulate the release of catecholamines which bind to the beta-
adrenergic receptors increasing heart rate.
what are the different methods for measuring cardiac output during exercise and
what are the advantages and limitations of techniques such as the Fick method
and echocardiography? - (ANSWER)Indirect ficks are invasive and specialist, they
involve a thermal or dye dilution and direct involve sticking needles into the right
ventricle indirect involve putting cold saline into blood and seeing how fast it
dilutes. Indirect method with CO2 rebreathe requires a stable VO2 and is invalid
when not in stead state VCO2. Impedance cardiograph is when can measure
electrical resistance across the chest and as the heart pumps through it changes
the electrical impedance but method is only good at rest. Ultrasound is good for
seeing dynamics as it can measure the speed of blood coming out.
Main chronic adaptations to endurance training that improve cardiac output and
overall performance - (ANSWER)Bigger end diastolic volume, bigger chamber
with trained heart has more ventricular mass from pressure loading the muscle.
Has improved calcium handling which improves myocardial contractility helping
the heart pump more effectively and increased rate of filling which improves
diastolic function allowing the heart to fill more rapidly contributing to increased
cardiac output.
How does training influence EDV, contractility and stroke volume? -
(ANSWER)Left ventricle becomes larger which allows greater filling during
diastole, improved calcium handling improves myocardial contractility and stroke
volume is influenced by increased EDV and contractility.
SPEX303 FINAL EXAM LATEST ACTUAL
EXAm QUESTIONS AND CORRECT
DETAILED ANSWERS
Why is BP important for physiological function? - (ANSWER)Ensures adequate
perfusion of tissues which is essential for blood to circulate to all the places it
should go
How does BP respond acutely to exercise and why does response depend on
intensity? - (ANSWER)Rises during static exercise, response depends on intensity
because blood pressure increase as cardiac output does to increased oxygen
demand from the working muscles.
How does cardiac output change during dynamic exercise and how is blood flow
distributed to different tissues during exercise? - (ANSWER)5-8 fold increase in
cardiac output. During exercise, blood flow to the GI tract and kidneys is reduced
but blood flow to the muscles increases as well to the brain slightly but the
change is a large relative decrease.
What factors control regional blood flow to tissues like the brain, muscles and
skin during exercise - (ANSWER)SNS nerves and receptors, myogenic
autoregulation specifically to the brain and kidney and metabolic auto regulation
such as temperature, pH, CO2 and ATP in the striated muscle
What role do local factors such as nitric oxide and metabolic byproducts play in
controlling blood flow to active muscles? - (ANSWER)NO released from muscle,
RBC's and endotheialil cells. NO promotes vasodilation with the released
mediated by mechanical stress on the blood vessel walls and hypoxia. Because NO
, 2
causes relaxation of the smooth muscle it leads to vasodilation which allow for
increased blood flow to active muscle due to decreased vascular resistance. CO
leads to localised vasodilation and ATP redistribute blood flow by stimulating SNS
meaning the heart beats faster and shuts down inactive muscle allowing for more
blood to be distributed to working muscles
How does blood volume typically change during acute exercise? -
(ANSWER)Commonly decreases at onset and within a few days it rises due to
stress hormones and depending on posture in hours post exercise.
What are the primary causes of acute plasma volume reduction in exercise? -
(ANSWER)Sweating which means fluid is lost decreasing plasma volume and fluid
lost into interstitial space due to decrease in capillary permeability which allows
fluid to leak through blood vessels into surrounding tissue
What are the primary determinant of stroke volume during exercise and how do
factored like preload and after load infueluce it? - (ANSWER)Preload, afterload
and contractility. Preload influences it as it determines the stretch of the heart
muscle fibers before contraction, a higher stroke volume is experienced as the
heart stretches with increased blood volume which generates a stronger
contraction. Afterload influences it as reduced afterload during aerobic exercise
enhances stroke volume as vasodilation in active muscles decreases systemic
vascular resistance.
How does heart rate respond to increasing exercise intensity, and what role do
the sympathetic and parasympathetic nervous systems play in this response? -
(ANSWER)Heart rate rises with increasing exercise intensity, but those trained
have a lower HR at any given intensity. At low to moderate intensity, HR increases
quickly due to withdrawal of the PNS and slight activation of SNS. At moderate to
, 3
high intensity HR continues to rise due to greater activation of the SNS, at
moderate intensities stroke volume plateaus so further increases in cardiac
output rely primarily on heart rate. At rest the PNS helps to keep heart rate low
but at the onset of exercise, it is withdrawn. The SNS takes over at moderate to
high intensities to stimulate the release of catecholamines which bind to the beta-
adrenergic receptors increasing heart rate.
what are the different methods for measuring cardiac output during exercise and
what are the advantages and limitations of techniques such as the Fick method
and echocardiography? - (ANSWER)Indirect ficks are invasive and specialist, they
involve a thermal or dye dilution and direct involve sticking needles into the right
ventricle indirect involve putting cold saline into blood and seeing how fast it
dilutes. Indirect method with CO2 rebreathe requires a stable VO2 and is invalid
when not in stead state VCO2. Impedance cardiograph is when can measure
electrical resistance across the chest and as the heart pumps through it changes
the electrical impedance but method is only good at rest. Ultrasound is good for
seeing dynamics as it can measure the speed of blood coming out.
Main chronic adaptations to endurance training that improve cardiac output and
overall performance - (ANSWER)Bigger end diastolic volume, bigger chamber
with trained heart has more ventricular mass from pressure loading the muscle.
Has improved calcium handling which improves myocardial contractility helping
the heart pump more effectively and increased rate of filling which improves
diastolic function allowing the heart to fill more rapidly contributing to increased
cardiac output.
How does training influence EDV, contractility and stroke volume? -
(ANSWER)Left ventricle becomes larger which allows greater filling during
diastole, improved calcium handling improves myocardial contractility and stroke
volume is influenced by increased EDV and contractility.
