NEW SPEX303 ACTUAL EXAM Q&A NEW
MODIFIED TESTED AND APPROVED GRADED
A+
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 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.
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.
Page 1 of 81
,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.
How does exercise training enhance cardiac resilience against ischemia and
reperfusion injury? -- ANSWER--Increased antioxidants such as MnSOD help
mediate cardiac resistance as they reduce oxidative stress, heat shock proteins
help repair damaged proteins in the heart muscle. Potassium channels are
maintained which helps restrict the calcium accumulation which can cause
ischaemia.
How does exercise training affect autonomic function and blood volume, and
what role do these extrinsic factors play in supporting cardiac output during
exercise? -- ANSWER--Exercise increases plasma volume and RBC which
contribute to a higher blood volume which enhances venous return increasing
preload and resulting in a greater stroke volume.
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
Page 2 of 81
,moderate to 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 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.
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
Page 3 of 81
, 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.
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
Page 4 of 81
MODIFIED TESTED AND APPROVED GRADED
A+
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 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.
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.
Page 1 of 81
,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.
How does exercise training enhance cardiac resilience against ischemia and
reperfusion injury? -- ANSWER--Increased antioxidants such as MnSOD help
mediate cardiac resistance as they reduce oxidative stress, heat shock proteins
help repair damaged proteins in the heart muscle. Potassium channels are
maintained which helps restrict the calcium accumulation which can cause
ischaemia.
How does exercise training affect autonomic function and blood volume, and
what role do these extrinsic factors play in supporting cardiac output during
exercise? -- ANSWER--Exercise increases plasma volume and RBC which
contribute to a higher blood volume which enhances venous return increasing
preload and resulting in a greater stroke volume.
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
Page 2 of 81
,moderate to 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 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.
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
Page 3 of 81
, 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.
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
Page 4 of 81
