Ch. 18 The Cardiovascular System: The Heart

The coronary arteries arise from the

aorta

prevents backflow of blood into the left ventricle

aortic semilunar valve

The most muscular chamber of the heart is the

left ventricle

Which of the following would lead to a decrease in heart rate? norepinephrine parasympathetic stimulation sharply decreased blood volume exercise

parasympathetic stimulation

During systemic circulation, blood leaves the

left ventricle and flows directly to the aorta

When the mitral valve closes, it prevents the backflow of blood from the

left ventricle into the left atrium

Guided by powerful signaling molecules, the human heart develops from

mesoderm

valve between the left atrium and left ventricle

mitral (bicuspid) valve

The noncontractile cardiac muscle cells that initiate their own depolarization and cause depolarization of the rest of the heart are called

pacemaker cells

The tricuspid valve is located between the

right atrium and right ventricle

From the perspective of blood returning from the systemic circuit, identify the correct sequence of blood flow through the chambers of the heart: lungs, right ventricle, left ventricle, right atrium, left atrium left ventricle, left atrium, lungs, right ventricle, right atrium left atrium, left ventricle, right ventricle, right atrium, lungs right ventricle, left ventricle, left atrium, lungs, right atrium right atrium, right ventricle, lungs, left atrium, left ventricle

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

supplies blood to the lateral right side of the myocardium

right marginal artery

The role of the atrioventricular node (AV node) is to

slow down impulses so that the atria can contract to fill the adjacent ventricles with blood

The __________ nerve carries parasympathetic fibers to the sinoatrial (SA) node.

vagus

cardiac output = __________ x _________

heart rate x stroke volume

The inferior vena cava brings blood from the lower regions of the body and empties into the

right atrium

An enlarged R wave on an ECG would indicate

an enlarged ventricle

supplies blood to the interventricular septum and anterior walls of both ventricles

anterior interventricular artery

The contractile cardiac muscle fibers of the myocardium behave as a single, coordinated unit called a

functional syncytium

The vessels that carry oxygen to the myocardium are called

coronary arteries

The superior chambers of the heart are called the

atria

relaxation

diastole

The trabeculae carneae are located in the

ventricles

The normal pacemaker of the heart is the

SA node

Choose the correct sequence of electrical current flow through the heart wall. AV node, SA node, subendocardial conducting network, AV bundle, right and left bundle branches subendocardial conducting network, AV node, AV bundle, right and left bundle branches, SA node AV node, subendocardial conducting network, AV node, AV bundle, right and left bundle branches SA node, subendocardial conducting network, AV node, AV bundle, right and left bundle branches SA node, AV node, AV bundle, right and left bundle branches, subendocardial conducting network

SA node, AV node, AV bundle, right and left bundle branches, subendocardial conducting network

Which of the following statements is NOT true about the shape, position, and location of the heart? The heart is located between the two lungs within the mediastinum. Approximately two-thirds of the heart is found to the left of the midline. The heart is enclosed in a double-layered sac called the pleural membrane. The heart is shaped like a cone with the base facing the right shoulder.

The heart is enclosed in a double-layered sac called the pleural membrane.

The P wave of an electrocardiogram represents

atrial depolarization

the events associated with blood flow through the heart during one complete heartbeat

cardiac cycle

An elevated S-T segment on an ECG indicates

cardiac ischemia

the amount of blood pumped by each ventricle in one minute

cardiac output

the amount of blood pumped out of each ventricle in one minute

cardiac output

Which of the following are correctly paired? arrhythmia: atrioventricular (AV) node failure heart block: uncoordinated atrial and ventricular contraction fibrillation: premature contraction ectopic focus: an abnormal pacemaker

ectopic focus: an abnormal pacemaker

The lining of the heart chambers is called the

endocardium

A doctor puts his stethoscope on a patient's chest over the location of the heart and hears an abnormal swishing sound. Which of the following conditions is the best diagnosis for the patient's condition? cardiac tamponade myocardial infarction angina pectoris incompetent cardiac valve

incompetent cardiac valve

The interventricular septum forms a dividing wall between the

left and right ventricles

lines the internal surface of the fibrous pericardium

parietal layer of serous pericardium

The structure just deep to the fibrous pericardium is the

parietal layer of the serous pericardium

runs to the apex of the heart

posterior interventricular artery

prevents backflow of blood into the right ventricle

pulmonary semilunar valve

the volume of blood pumped by one ventricle with each heartbeat

stroke volume

contraction

systole

Which of the following structures is superficial to the heart wall and serves to protect the heart, anchor the heart, and prevent the heart from overfilling? the epicardium the parietal layer of serous pericardium the fibrous pericardium the pericardial sac

the epicardium

Which of the following is NOT a role of the fibrous pericardium? It prevents the heart from overfilling with blood. It facilitates heart contraction. It protects the heart. It anchors the heart to surrounding structures.

It facilitates heart contraction

Which of the following is a difference between cardiac muscle and skeletal muscle? Unlike skeletal muscle cells, cardiac muscle cells do not rely on calcium ions for contraction. Unlike skeletal muscle cells, cardiac muscle cells can be autorhythmic. Unlike skeletal muscle, cardiac muscle is not striated. Unlike skeletal muscle, cardiac muscle does not use a sliding filament mechanism for contraction.

Unlike skeletal muscle cells, cardiac muscle cells can be autorhythmic.

Which of the following factors gives the myocardium its high resistance to fatigue? the presence of intercalated discs a very large number of mitochondria in the cytoplasm the coronary circulation gap junctions

a very large number of mitochondria in the cytoplasm

often muffles cardiac sound so that no heart sounds can be heard

cardiac tamponade

The __________ are attached to the AV valve flaps

chordae tendineae

supplies blood to the left atrium and posterior walls of the left ventricle

circumflex artery

The second heart sound (the "dup" of "lub-dup") is caused by the

closure of the semilunar valves

Which is the correct sequence of layers in the heart wall, starting with the outer layer? epicardium, myocardium, endocardium parietal pericardium, myocardium, endocardium endocardium, smooth muscle, epicardium endocardium, epicardium, myocardium myocardium, pericardium, endocardium

epicardium, myocardium, endocardium

Into which chamber of the heart do the pulmonary veins deliver blood?

left atrium

Freshly oxygenated blood is delivered to the __________, and then it passes into the __________ to be pumped to the body tissues (systemic circuit).

left atrium; left ventricle

During pulmonary circulation, blood leaves the

right ventricle and flows directly to the lungs

The endocardium is composed of

simple squamous epithelium

What part of the heart is considered the systemic circuit pump

the left ventricle

The absolute refractory period refers to the time during which

the muscle cell will not respond to a stimulus of any strength

The cardiac cycle includes all of the following events EXCEPT __________. the changes in pressure gradients in all chambers of the heart the closing and opening of the heart valves during each heartbeat the number of times the heart beats in one minute the movement of impulse from the SA node to all regions of the heart wall the changes in blood volume in all chambers of the heart

the number of times the heart beats in one minute

valve between the right atrium and right ventricle

tricuspid valve

Which valve is most often faulty in the heart?

the mitral, or bicuspid, valve

T/F: In the fetus, blood from the left and right sides of the heart normally mix.

true