Flashcards in Deck 3 Deck (38):
SBP or DBP indicates peripheral resistance or ease that blood flows from arterioles into capillaries?
SBP or DBP provides estimate of work of heart and force blood exerts against arterial walls during systole?
Average force exerted by blood against arterial wall during cardiac cycle.
How does blood from the veins return to the heart?
- muscle contractions
- pressure changes within the thoracic cavity during breathing
Does exercise prevent varicose veins?
No, but it helps minimize discomfort and complications
What are varicose veins?
Failure of valves to to maintain one-way blood flow, so blood pools and distends veins
What happens to BP during resistance exercise?
It increases because as muscles contract, peripheral resistance increases, which in turn increases CO to restore muscle blood flow
What happens to BP (specifically SBP) during steady-rate physical activity like running?
vasodilation decreases peripheral resistance, so SBP decreases because the heart does not have to push as hard
During regular, graded exercise SBP linearly increases. What happens to DBP?
it remains constant or even decreases slightly
Individuals with cardiovascular dysfunction should rhythmically exercise relatively _______ muscle groups. Why?
large, because smaller groups offer greater resistance to flow and increase SBP and DBP.
How do you explain the large SV and low HR you see with well trained athletes?
- increased vagal tone an decreased sympathetic drive
- increased blood volume and myocardial contractility
Although their HR's may be the same, a trained individual has a greater what? Giving them a higher CO.
What can increase the heart's SV during exercise?
- enhanced filling during diastole, and a greater push during systole
- more emptying during systole
- training adaptations that increase blood volume and reduce peripheral resistance
How can we enhance diastolic filling?
- increase the return of blood
- slow down HR to allow more filling
What does the Frank-Starling relationship state?
The more cardiac muscle fibers are stretched, the harder they will contract when emptying
What effects the a-VO2 difference during physical activity?
blood being diverted to active tissue
Which has greater increases in VO2 max, arm or leg exercise?
Which produces greater physiologic strain and is less economical, arm or leg exercise?
What is the limiting factor for exercise: respiration or circulation?
As you inspire, what happens to intrapulmonic pressure compared to atmospheric pressure?
it is less than atmospheric pressure
Is inspiration or expiration a passive process?
What is greater, IRV or ERV?
What is residual volume?
Air remaining in the lungs after a forced expiration
What allows an uninterrupted exchange of gas between the blood and alveoli to prevent fluctuations in blood gases during phases of the breathing cycle?
FEV1.0 ÷ FVC = what for healthy adults?
What is maximum voluntary ventilation (MVV)?
evaluates ventilatory capacity with rapid deep breathing for 15s
How can you improve your maximum voluntary ventilation (MVV)?
exercise ventilatory muscles
minute ventilation is equal to what?
breathing rate x tidal volume
What is more likely to increase to a greater degree during INTENSE exercise: breathing rate or tidal volume?
Why does the valsalva maneuver reduce venous return to the heart?
The contracting diaphragm and increased intra abdominal pressure collapses the inferior vena cava
An active muscle’s uncompromising capacity to use available oxygen in its large blood flow supports the position that :
oxygen supply from circulation, not oxygen use, limits aerobic capacity
Small increases in ______ in inspired air trigger large increases in minute ventilation
What is the ventilatory threshold?
point of disproportionate increase in minute ventilation compared to VO2
Lactate threshold (LT) describes highest VO2 or exercise intensity before a _____ mM increase in blood lactate concentration above the pre-exercise level.
What is at a higher intensity (4.0 mMol) of lactic acid: Lactic Threshold (LT) or Onset of Blood Lactate Accumulation (OBLA)?
Endurance training lowers blood lactate levels and extends exercise before onset of blood lactate accumulation during exercise by:
- decreasing rate of lactate formation
- increasing rate of lactate clearance
- combined effects of both
Why measure lactic threshold?
- great indicator of aerobic training status
- greater predictor of endurance performance (more than VO2!)
- explains active muscles aerobic metabolic dynamics