Cardiovascular Responses to Exercise Flashcards
What is the reduction of tonic contractile tension called?
Vasodilation
During exercise, what increases in order to allow blood flow to reach the working muscle better?
vessel diameter
Most changes occur at the level of the ____ during exercise for vasodilation
arterioles
The primary mechanisms for vasodilation include
- ____ vasodilators
- ___ stress to release NO from the ___ cells
increases
shear; endothelial
What 4 main vasodilators are mentioned as primary mechanisms for vasodilation?
- Adenosine
- Potassium
- CO2
- Lactic Acid
What vasodilator increases PKA, decreases cytosolic free calcium and decreases MLCK ?
adenosine
What vasodilator(s) increase hyperpolarization and decreases cytosolic free calcium?
Potassium
Co2
Lactic Acid
What type of feedback loop is shear stress and NO?
Negative
Local vasodilation ____ shear stress, which increases the endothelial ___ synthase activity
increases; NO
NO activates ___ cyclase which increases c___ production
guanylyl
cGMP
What does cGMP activate?
PKG, which has similar effects to PKA
Vasoconstriction occurs within ____ and shunts blood to working muscle in order to maintain ____
internal organs; blood pressure
Small changes in the ___ inner diameter makes a large difference in blood flow
arteriole’s
Muscle cells consume ___ and create waste byproducts like ___
Oxygen; CO2
As muscle work longer/harder, they need more oxygen to create more ___. This increases the ___ rate and ___ to exercising muscles
ATP; respiration; blood flow
An increased demand for systemic oxygen consumption (VO2) are met according to which equation?
Fick Equation
VO2 = [HR x SV] x (A-V O2 Difference)
VO2 = CO x (AV O2 Difference)
The A-V O2 difference is the amount of oxygen extracted from the blood and ___ with increasing rates of exercise as tissue oxygen uptake increases
increases
What is your CO at rest?
4-6 L/min
How do you determine Stroke Volume? What is it influenced by (3)?
SV = EDV - ESV
influenced by preload/afterload/contractility
SV increases EARLY during acute exercise and reaches its maximum around __-__% VO2 Max
40-50%
As parasympathetic activity increases, HR ____
decreases
As sympathetic activity increases, HR ____
increases
HR increases with activity continuously until what is achieved?
VO2 Max
During exercise, there is an initial withdrawal of ___ (parasympathetic) activity followed by an addition of ____ sympathetic drive to pacemaker cells
vagal
increase
Pacemaker cells during exercise ___ K+ conductance, ___ depolarizing inward (Na+) currents, which brings the SA node membrane potential to threshold rapidly
decreases
increasing
Exercise increases the rate of spontaneous SA node _____
depolarization
BP = CO x _____
total peripheral resistance (TPR)
What is a health resting BP?
120/<80mmHg
With acute CV exercise, systolic BP _____ in proportion to increased intensity, while diastolic BP changes ____ REGARDLESS of intensity
increases; very little
Cardiovascular response is directly proportional to the ___ demands of the skeletal muscle during exercise
O2
Aerobic exercise uses ___ as the main fuel source whereas Anaerobic exercise uses ____ and ____ as primary fuel sources
oxygen
phosphocreatine and CHO
Over time, most changes from exercise adaptation occur via _____ efficiency and muscle _____ diameter
neuromuscular
cross-sectional
___ ventricular hypertrophy (thickening of myocardial tissue) occurs from training as a result of ___ overload
Left; pressure
T/F: The Metabolic Vasodilator activity significantly changes as a result of exercise
false; does NOT change significantly
Muscle conduit arteries expand with training. Example, the femoral artery of a trained athlete has a 7-9% WIDER lumen and THINNER wall compared to an untrained individual. This is known as what?
local arterial expansion
With training, the capillary density of trained muscles _____ as a result of capillary angiogenesis
increase
With training, blood volume ____ due to an increase in ____
increases; plasma volume
There is more plasma in the blood with trained individuals due to an increase in plasma ___ which cause more ___ to be retained in the blood
proteins; fluid
With training, ___ volume INCREASES however, since there is also a greater increase of plasma volume, the total ____ DECREASES
Red Blood Cell
Hematocrit
With training, blood viscosity ____ thus improving circulation and enhancing delivery of ____
decreases
oxygen
What 4 changes in the blood help to increase VO2?
- Capillaries
- Mitochondria
- Hemoglobin
- Myoglobin
What are the determinants of VO2?
- CO
- Workload
- Intensity
- Changes that increase VO2 (capillaries, mitochondria, hemoglobin, myoglobin)
Endurance training ___ SV at REST and during submax and max exercise due to an increased heart/chamber size in the left ventricle which will stretch and fill more, enhancing its _____
increases
contractility
HR adaptations to Training:
- Resting HR ____
- Submax HR ____
- Max HR _____ slightly
decreases
decreases
decreases
A normal HR recovery with training is a decrease of greater than or equal to ___ beats within ONE minute of stopping exercise
12
Higher CO is achieved post-training at ___ workloads due to an increased ____
maximal; SV
Using the upper body during the same type of exercise causes a greater increase in what?
Blood Pressure
During acute exercise, metabolically-induced increases in blood flow lead to arteriolar vaso_____ which increases the amount of _____ that are well perfused
dilation
capillaries
With training, vascular endothelial growth factor (VEGF) ____ capillary angiogenesis
increases
With training, capillary density increases from -/muscle fiber to __-__/muscle fiber
1-3
6-8
Dynamic exercise is considered any movement that is ____
rhythmic
HR, CO, VO2 (oxygen consumption) all increase _____ with exercise intensity up to ____
linearly; max
There are ___ effects on arterial blood pressure with training
moderate
In dynamic arm exercise, there is a ___% greater increase in ___ blood pressure than in dynamic leg exercises
10
arterial
With training, total peripheral resistance goes ____ (uncommon with an increase in _____)
down
arterial blood pressure
an increase in blood flow is called _____ and occurs with training
hyperemia
Providing adequate ____ to support exercise-induced hyperemia is the primary driving force for most CV effects of dynamic exercise
CO
The increase in bp by isometric exercise is far greater than the
metabolic cost of the exercise
HR and BP is greater in _____ exercise when circulation and intensity are similar
isometric
Increase in MAP is proportional to size of ___ and duration of ___ during isometric exercise
muscle; contraction
What type of exercise never reaches a steady state?
isometric
With isometric exercise, bp can increase
dramatically
With isometric exercise, there is an increase of blood flow of __-__% of MVC (muscle flow increases with muscle relaxation)
30%
40-60%
With isometric exercise, the respiratory response is that the hemodynamic parameters are ____ and there is systemic ____
normal
hypoxia
With isometric exercise, CVD patients have normal levels of ____ oxygen and limited levels of ____
arterial
CO
Mitral Stenosis causes a low ___, but max HR and max oxygen consumption are relatively ____
stroke volume; normal
How do patients with Mitral Stenosis compensate for the effects of exercise?
at rest, increase their HR and oxygen consumption
Mitral Stenosis impairs muscle ____
blood flow
The Cardiovascular effects of dynamic exercise is driven by active muscles demand for ____, which increases the ___ from an increase in ____, blood flow and sympathetic tone
oxygen
CO
venous return
Isometric exercise increases ____ and ____
HR; MAP
In general, exercise effects may be limited by ___ transport
oxygen
