study guide packet

broadest part of the heart

base

receives deoxygenated blood from the body

right atrium

pumps blood to the lungs

right ventricle

pumps oxygenated blood to the body

left ventricle

receives oxygenated blood from the lungs

left atrium

the point of maximum impulse (PMI)

apex

located between the right atrium and the right ventricle

tricuspid valve

located between the right ventricle and the pulmonary artery

pulmonary valve

located between the left ventricle and the aorta

aortic valve

located between the left atrium and the left ventricle

mitral valve

a fibrous connective tissue that encircles each valve

skeleton of the heart

a double-walled sac that surrounds the heart

pericardium

a space that contains serous fluid to prevent friction as the heart beats

pericardial cavity

A thin layer of squamous epithelial cells that lines the chambers of the heart, covers the valves, and continues into the vessels

endocardium

Cardiac muscle that performs the work of the heart

myocardium

a thin layer of squamous epithelial cells that covers the surface of the heart

epicardium

What is the correct progression of the cardiac impulse?

SA node, AV node, bundle of His, Purkinje fibers

what term refers to the heart’s ability to initiate its own electrical impulse?

automaticity

based on your memory of the heart’s electrical system, what will happen if a patient’s primary pacemaker fails?

another area of the electrical system will initiate a heartbeat

what is the correct progression of blood through the heart and lungs?

right atrium, right ventricle, lungs, left atrium, left ventricle

what is the most likely outcome of mitral valve incompetence?

blood will flow backward into the left atrium

based on your understanding of how the heart works, which of the heart’s chambers would you expect to have the thickest (strongest) walls?

left ventricle

which blood vessel(s) carries oxygenated blood to the left atrium?

pulmonary veins

what effect, if any, would persistent tachycardia have on cardiac output and why?

it would decrease cardiac output because filling time is decreased, which decreases stroke volume

the right coronary artery supplies blood to which area of the heart?

right atrium, most of the right ventricle, and parts of the left atrium and ventricle

which artery supplies blood to the front and main wall of the left ventricle?

anterior descending

which of the following describes a characteristic of cardiac muscle?

it is branched

what are gap junctions and what purpose do they serve?

they are small channels within intercalated disks that allow impulses to pass quickly from one cell to the next

an area of necrosis develops in the myocardium of the left ventricle as a result of a myocardial infarction. what complication is most likely to occur?

a backup of blood into the pulmonary circulation

a patient who normally has a pulse rate of 82 beats per minute is admitted to the cardiac unit with a pulse rate of 46 beats per minute. which part of the cardiac conduction system is most likely initiating cardiac impulses?

AV node

the heart’s skeleton

electrically insulates the ventricles from the atria

the series of events that occur from the beginning of one heartbeat to the beginning of the next is the _____.

cardiac cycle

which of the following factors determines cardiac output?

heart rate and stroke volume

what is the endocardium?

the inner layer of the heart wall

the coronary arteries receive their blood supply when

both ventricles relax

a weak left ventricle will have the greatest impact on

contractility

a stenotic aortic valve will increase

afterload

what effect will a positive inotropic medication have on cardiac function?

it will increase contractility

in which area of the brain is the cardiac center located?

medulla

stimulation of the vagus nerve will have what effect on the heart?

decrease heart rate

which system does the cardiac acceleratory center activate in response to emotional stress or increased physical activity?

sympathetic nervous system

which receptors detect changes in carbon dioxide and oxygen levels in the blood?

chemoreceptors

if the amount of blood returning to the left ventricle of a healthy heart increases slightly, according to Starling’s law of the heart, what will occur?

contractility will increase

Starling’s law of the heart describes the relationships among

end-diastolic ventricular volume, muscle fiber stretching, and contractile force

what causes the cardiac valves to open and close?

pressure changes in the cardiac chambers cause the valves to open and close

which of the following is a characteristic of the endocardium and why is it important?

the endocardium is smooth, which helps prevent blood clot formation

which of the following correctly identifies the phases of the cardiac cycle?

passive ventricular filling, atrial systole, isovolumetric contraction, ventricular ejection, isovolumetric relaxation

damage to the electrical pathway between the SA node and AV node would be reflected by which change on an ECG tracing?

a long PR interval

the cardiac impulse normally slows down at

the AV node to give the atria time to empty and the ventricles time to fill

the ejection fraction is a measurement directly related to

stroke volume

what is the average ejection fraction for a healthy heart?

70%

what causes a myocardial infarction?

a blood clot or fatty deposit in a coronary artery

the heart is approximately the size of a human ____.

fist

a heart valve that has become narrowed, such as from scar tissue, is said to be ____.

stenotic

a heart valve that allows blood to leak backward or regurgitate is said to be ____.

incompetent

the heart is located in a space in the thoracic cavity called the ____.

mediastinum

two almond-shaped areas of the brain called ____ stimulate the increase in heart rate that results from emotions such as fear and anger.

amygdala

left-sided heart failure will cause pulmonary ____.

edema

the section of the ECG that represents ventricular depolarization is the _____

QRS complex

the P wave on an ECG represents _____.

atrial depolarization

The area where the strongest heartbeat can be felt or heard is called the ____.

point of maximum impulse

heart valves are formed by either two or three flaps of tissue called ____.

cusps/leaflets

the action that supplies the ventricles with the last 30% of blood is called ____.

atrial kick