Cardiopulmonary Adaptations Flashcards
Fick principle takes into consideration:
Measures CO directly
VO2
arteriole and venous O2 difference
SV decreases as you age. T/F?
True, about 15% ages 20-80
CO adaptations at rest
1) Increase vagal tone and decreased sympathetic drive (HR)
2) Increase blood volume, myocardial contractility, compliance of LV (SV)
CO during exercise
achieve large CO primarily through large SV
SV:
Increase contractility
Activation of skeletal muscle pump and activation of respiratory pump (increases venous return)
3 physiological mechanisms increase the heart’s SV during exercise
1) Myocardial factor - enhances filling diastole, forceful systolic contraction
2) Neurohormonal factor - normal ventricular filling w/ forceful ejection during systole
3) Training adaptations - increase blood volume and reduced resistance to blood flow in peripheral (afterload)
Cardiovascular drift
Gradual time-dependent downward drift in SV with an increase in HR during prolonged steady-rate exercise
Decrease preload
Decrease SV
Increase HR to maintain CO
20-30 mins into prolonged exercise
SV in exercise
decreases and HR increases
Not cutaneous blood flow, it’s the results of increase in HR that results in decrease in SV
Hb saturation w/ O2 remains nearly complete…
Each lite of arterial blood carries 200 ml of O2
Increase in CO proportionate w/ increase in capacity to circulate O2, effecting max O2 consumption
avO2 diff
Hb releases quantity of it’s reserve O2 from blood
O2 consumption increases by:
1) increase in the total quantity of blood pumped by the heart (CO)
2) Greater use of the relatively use of O2 already carried by the blood
Submax tests uses more O2 in UE or LE?
UE tests
1) decrease mechanical efficiency in UE - additional cost of static muscle actions
2) recruitment of additional musculature = stabilize the worse during arm exercise
Cardiac hypertrophy
Eccentric - increase size of the LV
Concentric - modest thickening of the myocardial wall
HR adaptations
resting and sub maximal bradycardia result from exercise training
4 factors SV
1) increase LV volume/mass
2) decrease cardiac stiffness
3) increase diastolic filling time
4) increase cardiac contractile function
CO is linear to O2 consumption. T/F?
True
How much VO2 is decreased after 2 weeks bedridden?
10%
RV
temporarily increase from an acute bout of either short-term or prolonged exercises
Results:
1) closure of small peripheral airways
2) increase thoracic blood volume
What effects lung volume?
Taller people! Doesn’t change with exercises except swimmers/divers!
TV increases with exercise. T/F
True
Frequency increase with exercise
Expands largely into IRV
Small decrease in expiratory
Dyspnea
result from increase CO2 and H
How to push lactate threshold?
Interval training
Altitude training
Live high, train low
above 8000 feet for adaptation
*poor evidence
months for RBC change
Factors that control ventilation
Chemical Cortisol Peripheral influence Temp Multiple factors!!
Does ventilation limit exercise?
Pulmonary ventilation does not limit O2 transport in healthy individuals since minute vent at VO2max equals only 60-85% of healthy MVV
