2C exercise phys

At rest, most blood is in

viens

During exercise, vasoconstriction of veins in nonworking skeletal muscle, the gut, and other areas and also increased perfusion to skeletal muscle capillaries redistributes blood so that in contrast to the resting state, most blood is in

arteries and capillaries

The right ventricle pumps blood to the ___________, while the left ventricle pumps blood to ______________.

ungs; systemic circulation

High arterial blood pressure in the systemic circulation causes the _______ ventricle to work harder to eject the same amount of blood compared to a condition of lower systemic blood pressure.

left

Vascular resistance to blood flow is inversely proportional to the fourth power of the vessel radius.  This means that small changes in vessel diameter

substantially affect resistance

These factors contribute to venous return of blood to the heart

all of the above

Alpha and beta blockers prevent actions of

catecholamines (epinephrine, norepinephrine)

Blood pressures are highest under the following condition

lifting heavy weights

Aerobic exercise produces higher blood pressures when the exercise is with the

upper body

At rest, the prominent fuel for cardiac muscle is

 

fatty acids

During intense aerobic exercise, the main fuel for cardiac muscle is

lactic acid

Pacemaker cells of the _____________ originate the depolarization that leads to cardiac muscle contraction

sinoatrial node

Differences in rates propagation of the sinoatrial node depolarization to the atria and ventricles cause

atria to contract before ventricles

The electrical pattern of the cardiac cycle includes

all of the above

An anticipatory increase in heart rate before initiation of exercise is evidence for

central command

A chronotropic stimulus ________ heart rate.

increases

A stimulus that increases contractility (force of contraction) of the heart is

inotropic

The parasympathetic neurotransmitter acetylcholine causes

hyperpolarization of sinoatrial pacemaker cells

Nitric oxide (NO) causes

smooth muscle cell relaxation and resultant vasodilation

A noninvasive measure of cardiac output involves

the CO2 rebreathing method that uses breath CO2 measurements for estimation of PvCO2 and PaCO2 and subsequent calculation of cardiac output

If resting heart rate is 50 beats per minute, and cardiac output is 5 liters per minute, what’s resting stroke volume?

5 L-→ 5000 ml /50 beats so 100 mL

What factor is responsible for cardiac drift (slow increase in heart rate during prolonged, steady workload aerobic exercise?

all of the above

Perfusion (blood flow in ml/minute) increases during aerobic exercise to all of these tissues EXCEPT

kidneys

VO2 is a product of

all of the above

At the same aerobic power output, greater cardiovascular responses are caused by

arm exercise

VO2max occurs when heart rate is

at its max

Force generating capacity of cardiac myocytes is greatest

at the end of diastole, when the ventricle is maximally loaded and stretched