PCB 4701 Ch 14 Difficult Quiz

If someone's heart has a stroke volume of 70 ml and a heart rate of 90 beats/min, the cardiac output equals _____________.

6.3 L/min

Contraction of the left ventricle of the heart at rest normally expels about ______ of the blood contained in the chamber.

60(--)70%

All parasympathetic nerve fibers to the heart innervate the SA node.

False

Since the veins contain most of the body's blood at any one time, they have a higher blood pressure than any other type of vessel.

False

The heart's contractility is adjusted so that normally each ventricle expels all the blood contained in it, leaving none behind in the chamber.

False

Cardiac control centers in the medulla oblongata receive input from baroreceptors located in some of the arteries.

True

In spite of the fact that the systemic vessels cover substantially more total length than the pulmonary vessels, the same amount of blood must flow through both of these systems at a given time.

True

Stroke volume is directly proportional to end-diastolic volume.

True

According to the classic view of the Starling forces, capillaries usually tend to absorb fluid ________________.

at the venular end

Stroke volume is regulated by all of the following except ____________.

cardiac output

Veins are said to have a higher ____ than arteries because they expand more easily and a higher ___________ because they contain more blood.

compliance; capacitance

During exercise, the cardiac output may rise to five times the resting value. In most people this is due mainly to an increase in ______________.

heart rate

A positive inotropic agent is something that _______________.

increases the contractility of myocardial fibers

Pulmonary edema, shortness of breath, and fatigue are most likely to result from _________________.

left-sided congestive heart failure

During systole, the ventricular myocardium gets its oxygen supply mainly from _______.

myoglobin

Myxedema is a disease caused by hypothyroidism, which causes production of excessive amounts of glycoprotein in the Interstitial spaces. The effect of this on capillary fluid dynamics would be to cause ________________.

reduced osmotic return of fluid and thus accumulation of fluid in the tissues resulting in edema

The hydrostatic pressure of blood in a capillary is 19 mmHg and that of the tissue fluid is 1 mmHg, while the colloid osmotic pressure of the blood is 23 mmHg and that of the tissue fluid is 0 mm Hg, at this particular portion of the capillary, fluid is being _______ with a net force of __________.

taken up; -5 mmHg

During fight or flight reaction, the sympathetic nervous system causes vasodilation in skeletal muscle but vasoconstriction in the skin. It is able to achieve these opposite effects because ___________________.

the binding of norepinephrine to the §-adrenergic receptors in skeletal muscle arterioles causes vasodilation whereas binding of norepinephrine to a-adrenergic receptors in the skin arterioles causes vasoconstriction.

Cardiac output may drop when one goes from lying to a standing position because of ________________.

venous pooling