Cardiovascular changes during exercise Flashcards
What are 5 adjustments our body makes to exercise
Cardiovascular responses
Respiratory Responses
Skeletal muscle and bone responses
Immune responses
Body fluid and salt changes
Which parameter can be used to indicate cardiorespiratory fitness
Maximal 2 consumption
What is the equation for maximal O2 consumption
VO2 max = max. Q x max. a-vO2
Factors affecting maximal oxygen consumption
Heredity, age, sex, body size and composition, training status, types of muscle fibers used during exercise, altitude, temperature
What are the acute cardiovascular responses to exercise
Redistribution of Blood Flow (local vs neural)
Increased heart rate
Increased stroke volume
Increased cardiac output
Changes in blood pressure
changes in venous return
Which organs get a reduced blood flow during acute exercise
liver, kidneys, GI track
Which tissues get a increased blood flow during acute exercise
coronary muscle, skin, cerebral tissues, skeletal muscle
sympathetic outflow causes selective arteriolar vasoconstriction to which tissues
liver, inactive muscles and splanchnic regions
Sympathetic outflow acts on which receptors to constrict arterioles during acute exercise
alpha 1-adrenergic receptors
In exercising muscle, what overrides any sympathetic vasoconstricting effects, and causes arteriolar vasodilation
Local metabolites
increase in which vasoactive metabolites during exercise aid in dilation of blood vessels
↑ nitric oxide (NO) ↑ K+ ↑ release of adenosine ↑ H+ ↑ CO2 ↑ T°
decrease in which vasoactive metabolites during exercise aid in dilation of blood vessels
↓ O2
↓ pH
In which tissues is there a biphasic response in blood flow during acute exercise
Cutaneous circulation (skin)
vasoconstriction then vasodilation
Heart rate increases at the beginning of exercise and levels of at what point
When exercise is at a constant pace
What are the two equation to predict the maximum heart rate
Standard equation: Max HR = 220 – age
Alternate equation: Max HR = 210 – (age x 0.65)
Which four things can increase stroke volume
increased preload
increased venous return
increase contractility
decreased TPR
Increase in SV causes a change in systolic or diastolic blood pressure
Systolic
What causes venous return to increase during exercise
The contraction of skeletal muscle around the veins
Activation of the sympathetic nervous system produces venoconstriction
What causes TPR to decrease during exercise
Vasodilation in skeletal muscle
What causes blood plasma volume to increase during exercise
Increased skin blood flow and an increase in sweating,
Increased blood pressure forces water from the vascular system to the interstitial spaces
Decrease in blood plasma volume results in a decrease in which cardiac output variable during exercise
SV
During rest exercise and recovery, in which stage is O2 supply greater than O2 demand
Recovery
Where is the most oxygen stored in the body
Combined with hemoglobin in the blood
The O2 debt during exercise must be repaid to which two systems
The phosphagen (ATP-creatine phosphate) system and the lactic acid system
What is the extra O2 used for during recovery
Lactic acid O2 debt (8 L): removal of lactic acid
Alactacid O2 debt (3.5 L): all other sources as described above
What are the cardiovascular adaptations to chronic exercise
Cardiac Hypertrophy and Increased Stroke Volume
Lower Resting and Working Heart Rate
Increased Cardiac Output at VO2 max
Increased Blood Volume and Hemoglobin Levels
Increased a-vO2
Increase in VO2 max
Endurance training leads to what kind of change in cardiovascular anatomy
thicker walls and greater volume
Resistance training leads to what kind of change in cardiovascular anatomy
thicker walls only
What are the benefits of having a lower resting and working heart rate
reduces resistance to blood flow and strain on heart
increased stroke volume increases efficiency
hate rate return to normal faster
What causes an increase in a-VO2 during chronic exercise
increases on mitochondria,
capillary density,
hemoglobin
myoglobin
What are the 4 major causes of muscle fatigue
Inadequate energy delivery/metabolism
Accumulation of metabolic by-products
Failure of muscle contractile mechanism
Altered neural control of muscle contraction
What is the lactate threshold
point at which blood lactate accumulation increases markedly
What is the anaerobic threshold
as the VO2 at which anaerobic metabolism contributes significantly towards the production of ATP
Which threshold is a non invasive estimate of cardiovascular function
anaerobic threshold
What does a low anaerobic threshold indicate
early hypoxia of exercising muscles – Suggests cardiovascular or pulmonary vascular limitation
