BIO 219: MAP #8 The Heart

The primary site of exchange between blood and interstitial fluid occurs across what type of blood vessel?

When blood leaves the heart, it first enters what type of blood vessel?

True/False: All veins contain deoxygenated blood.

The right ventricle of the heart pumps _____ blood into the _____.

Which chamber of the heart has the thickest musculature?

The opening and closure of the atrioventricular and semilunar valves is driven by ________.
a. differences in pressure across the valve
b. contraction and relaxation of the valve
c. contraction of the valve
d. contraction of muscles attached to the valves
e. contraction of the ventricle and atria that pull the valves into place

Closure of the atrioventricular valve occurs when ________.
a. the valve contracts
b. the papillary muscle contracts
c. pressure inside the ventricle is greater than pressure inside the atrium
d. pressure inside the ventricle is less than pressure inside the atrium
e. the atrium contracts

During the initial period of pacemaker potential from spontaneous depolarization to subthreshold, which channels are open?

The term autorhythmicity refers to the heart's ability to ________.

What structure provides the pathway for the movement of electrical current between the cells of the conduction pathway and the ventricular myocytes?
a. Gap junctions
b. Sodium Channels
c. Desmosomes
d. Funny Channels
e. Potassium channels

Opening of which of the following channels contributes to the spontaneous depolarization of pacemaker cells?
a. both calcium channels and funny channels
b. funny channels only
c. calcium channels only
d. both calcium and potassium channels
e. potassium channels only

The rapid depolarization phase of a pacemaker cell action potential is caused by which of the following types of ion movement?
a. movement of potassium through funny channels
b. movement of sodium through funny channels
c. movement of sodium and calcium through funny channels
d. movement of calcium through T-type channels
e. movement of calcium through L-type channels

Which of the following is responsible for the rapid depolarization phase of an action potential within the pacemaker cells?
a. An increase in PK
b. A decrease in PNa
c. A decrease in PK
d. An increase in PCa
e. An increase in PNa

Which of the following ion channels must open for a cardiac pacemaker cell to depolarize to threshold for an action potential?
a. funny channels only
b. T-type calcium channels only
c. both funny channels and T-type calcium channels
d. both funny channels and L-type calcium channels
e. L-type calcium channels only

Which component of an ECG represents ventricular depolarization?

Which component of an ECG represents ventricular repolarization?

In an ECG recording, the RR interval is 0.5 seconds. What is the heart rate?
a. 120 beats/min
b. 100 beats/min
c. 60 beats/min
d. 50 beats/min
e. 30 beats/min

True/False: The contractile cycle of the heart normally originates from a pacemaker cell within the sinoatrial node.

True/False: Calcium movement into the cell causes the rapid depolarization of the autorhythmic cell action potential, whereas sodium movement into the cell causes the rapid depolarization of the contractile cell action potential.

True/False: Calcium entering the cell during the plateau phase of the ventricular cell action potential triggers calcium release from the sarcoplasmic reticulum.

At the beginning of systole, when ventricular pressure exceeds atrial pressure, the AV valves close and the semilunar valves also remain closed because the pressure within the ventricles is still not sufficiently strong to force them open. At this point there is no flow of blood in or out of the ventricles. This phase is known as ___________.

The volume of blood ejected from the heart during one beat is known as ________.

During isovolumetric relaxation, ________.
a. the AV and semilunar valves are open and ventricular pressure is increasing
b. the AV and semilunar valves are closed and ventricular pressure is increasing
c. the AV and semilunar valves are open and ventricular pressure is decreasing
d. the AV and semilunar valves are closed and ventricular pressure is decreasing
e. the AV valves are open, the semilunar valves are closed, and ventricular pressure is decreasing

What is occurring during ventricular ejection?
a. the AV and semilunar valves are closed as ventricular pressure is increasing
b. the AV valves are open and the semilunar valves are closed as blood is leaving the ventricles
c. the AV and semilunar valves are open as blood is leaving the ventricles
d. the AV valves are closed and the semilunar valves are open as blood is leaving the ventricles
e. the AV valves are open and the semilunar valves are closed as ventricular pressure is increasing

What phase of the cardiac cycle is the heart in when all four valves of the heart are closed and ventricular pressure is less than atrial pressure?
a. isovolumetric conctraction
b. ventricular filing
c. isovolumetric relaxation
d. ventricular ejection
e. none

During which phase of the cardiac cycle are all four heart valves open?

The increase in ventricular volume early in diastole reflects ________.
a. the relaxation of the ventricle
b. the back-flow of blood from the aorta
c. the increased stiffness of the heart
d. the contraction of the atria moving blood into the ventricle
e. the passive movement of blood through the atrium and into the ventricle

The small increase in ventricular pressure observed late in diastole is caused by ________.
a. blood moving into the atria from vena cava
b. ventricular relaxation
c. atrial contraction
d. ventricular contraction
e. atrial relaxation

Blood is ejected from the left ventricle once pressure within ________.
a. the ventricle is less than pressure within the pulmonary artery
b. the muscles of the pulmonary semilunar valve relax
c. the ventricle is less than pressure within the aorta
d. the ventricle is greater than pressure within the pulmonary artery
e. the ventricle is greater than pressure within the aorta

With a systolic pressure of 135 mm Hg and a diastolic pressure of 75 mm Hg, mean arterial pressure would be ________.
a. 30 mm Hg
b. 95 mm Hg
c. 75 mm Hg
d. 60 mm Hg
e. 135 mm Hg

The end-diastolic volume minus the end-systolic volume is the ________.

The volume of blood ejected from the ventricle with each contraction can be described by the formula ________.

The SA node is innervated by ________.

Which of the following is an effect of parasympathetic activity to the heart?
a. The rate of spontaneous depolarization in SA nodal cells decreases.
b. cAMP is activated
c. SA nodal cells are depolarized.
d. Postganglionic neurons release acetylcholine, which binds to nicotinic cholinergic receptors in the SA node.
e. Heart rate is increased.

Under resting conditions, heart rate is primarily under the control of what control system?

An increase in heart rate can be mediated through which of the following?
a. a decrease in sympathetic activity only
b. a decrease in parasympathetic nervous activity only
c. an increase in parasympathetic activity and a decrease in sympathetic activity
d. a decrease in parasympathetic activity and an increase in sympathetic activity
e. an increase in sympathetic activity only

The preload is approximately the same as the ________.

A decrease in afterload will lead to which of the following?
a. decreased stroke volume
b. decreased heart rate
c. increased stroke volume
d. decreased cardiac output
e. increased heart rate

Based up the figure, if end-diastolic volume is 100 mL at rest, what would stroke volume be is sympathetic nervous activity increase?

Based upon the figure, if end-diastolic volume at rest is increased from 100 to 120 mL, what will the new stroke volume be?