The Heart - Lecture Practice Test

Which of the following will NOT increase the heart rate?

increased blood pressure

The second heart sound is heard during which phase of the cardiac cycle?

isovolumetric relaxation

Blood within the pulmonary veins returns to the ________.

left atrium

When viewing a dissected heart, it is easy to visually discern the right and left ventricles by ________.

noticing the thickness of the ventricle walls

Which vessel(s) of the heart receive(s) blood during right ventricular systole?

pulmonary trunk

The fact that the left ventricle of the heart is thicker than the right ventricle reveals that it ________.

pumps blood against a greater resistance

The electrical impulses that create the QRS complex represent:

ventricular depolarization

The semilunar valves are closed during:

ventricular diastole

The tricuspid valve is closed ________.

when the ventricle is in systole

Chronic release of excess thyroxine can cause a sustained increase in heart rate and a weakened heart.

True

Congestive heart failure means that the pumping efficiency of the heart is depressed so that there is inadequate delivery of blood to body tissues.

True

Paroxysmal atrial tachycardia is characterized by bursts of atrial contractions with little pause between them.

True

The left side of the heart pumps the same volume of blood as the right.

True

Tissues damaged by myocardial infarction are replaced by connective tissue.

True

The condition where fluid compresses the heart and limits its ability to contract is called ________.

cardiac tamponade

Norepinephrine acts on the heart by ________.

causing threshold to be reached more quickly

Normal heart sounds are caused by which of the following events?

closure of the heart valves

A foramen ovale ________.

connects the two atria in the fetal heart

Compared to skeletal muscle, cardiac muscle ________.

has gap junctions that allow it to act as a functional syncytium

Atrial depolarization

A

SA node

A

Select the correct statement about cardiac output.

A slow heart rate increases end diastolic volume, stroke volume, and force of contraction.

Damage to the ________ is referred to as heart block.

AV node

Which of the following is true concerning the intrinsic conduction system?

Action potentials pass slowly through the atrioventricular cells

Left ventricular contraction propels blood through which valve?

Aortic valve

AV bundle (select on picture)

C

Baroreceptors are located in the aorta and

Carotid

Bundle branches

D

Bundle branches (select on picture)

D

Point after which pressure begins to rise in the aorta

D

Point that represents the "dup" sound made by the heart.

E

Point that represents the "dup" sound made by the heart. (select on picture)

E

Purkinje fibers (select on picture)

E

Ventricular repolarization (select on picture)

E

An ECG provides direct information about valve function.

False

Arterial blood supply to heart muscle is continuous whether the heart is in systole or diastole.

False

Auricles slightly increase blood volume in the ventricles.

False

Autonomic regulation of heart rate is via two reflex centers found in the pons.

False

Cardiac muscle has more mitochondria and depends less on a continual supply of oxygen than does skeletal muscle.

False

Heart rate and stroke volume decrease under decreased parasympathetic stimulation

False

The "lub" sounds of the heart are valuable in diagnosis because they provide information about the function of the heart's pulmonary and aortic valves.

False

The papillary muscles contract after the other ventricular muscles so that they can take up the slack on the chordae tendineae before the full force of ventricular contractions sends blood against the AV valve flaps.

False

How many pulmonary veins are there?

Four

In the heart, an action potential originates in the:

Sinoatrial node

The sequence of travel by an action potential through the heart is: The sequence of travel by an action potential through the heart is:

Sinoatrial node, atrioventricular node, atrioventricular bundle, bundle branches, Purkinje fibers

Select the correct statement about the heart valves.

The AV valves are supported by chordae tendineae so that regurgitation of blood into the atria during ventricular contraction does not occur.

Select the correct statement about the function of myocardial cells.

The entire heart contracts as a unit or it does not contract at all.

Select the correct statement about the structure of the heart wall.

The myocardium is the layer of the heart that actually contracts.

Anastomoses among coronary arterial branches provide collateral routes for blood delivery to the heart muscle.

True

As pressure in the aorta rises due to atherosclerosis, more ventricular pressure is required to open the aortic valve.

True

Hemorrhage with a large loss of blood causes ________.

a lowering of blood pressure due to change in cardiac output

The term for pain associated with deficient blood delivery to the heart that may be caused by the transient spasm of coronary arteries is ________.

angina pectoris

The P wave of a normal electrocardiogram indicates ________.

atrial depolarization

During the period of ventricular filling ________.

blood flows mostly passively through the atria and the open AV valves into the ventricles

During the flow of blood through the body.

blood travels from the right ventricle to the lungs

Isovolumetric contraction ________.

refers to the short period during ventricular systole when the ventricles are completely closed chambers

Commotio cordis is heart failure due to a ________.

relatively mild blow to the chest that occurs during a vulnerable interval (2 ms) when the heart is repolarizing

Oxygen-poor blood enters which chamber of the heart?

right atrium

Each cardiac cycle takes about 8/10 of one

second

To auscultate the aortic semilunar valve, you would place your stethoscope in the ________.

second intercostal space to the right of the sternum

Which of the following factors does not influence heart rate?

skin color

During contraction of heart muscle cells ________.

some calcium enters the cell from the extracellular space and triggers the release of larger amounts of calcium from intracellular stores

If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells, ________.

tetanic contractions might occur, which would stop the heart's pumping action

If the vagal nerves to the heart were cut, the result would be that ________.

the heart rate would increase by about 25 beats per minute

The cardiovascular system consists of:

the heart, blood and blood vessels

Action potentials are conducted from the baroreceptors to the brain via:

the vagus and glossopharyngeal nerves

The action potential from the brain to the heart travels along

the vagus nerve

If we were able to artificially alter the membrane permeability of pacemaker cells so that sodium influx is more rapid, ________.

threshold is reached more quickly and heart rate would increase

The right atrioventricular valve is also alled the:

tricuspid valve