A&P Chapter 18 Study Questions

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

Right atrium

The tricuspid valve is located between the __________.

Right atrium and right ventricle

From the perspective of blood returning from the systemic circuit, what is the correct sequence of blood flow through the chambers of the heart?

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

During pulmonary circulation, blood leaves the __________ and flows to the __________.

Right ventricle and flows directly to the lungs

Where does the posterior interventricular artery run?

Runs to the apex of the heart

The normal pacemaker of the heart is the __________.

SA node

What is the correct sequence of electrical current flow through the heart wall?

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

The trabeculae carneae are located in the __________.

Ventricles

Which factor gives the myocardium its high resistance to fatigue?

A very large number of mitochondria in the cytoplasm

An enlarged R wave on an ECG would indicate __________.

An enlarged ventricle

The coronary arteries arise from the __________.

Aorta

The superior chambers of the heart are called the __________.

Atria

The P wave of an electrocardiogram represents __________.

Atrial depolarization

The __________ are attached to the AV valve flaps.

Chordae tendineae

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

Closure of the semilunar valves

Systole causes ______.

Contraction

The vessels that carry oxygen to the myocardium are called __________.

Coronary arteries

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

Left ventricle into the left atrium

The lining of the heart chambers is called the __________.

Endocardium

What is the correct sequence of layers in the heart wall, starting with the outer layer?

Epicardium, myocardium, endocardium

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

Functional syncytium

A doctor puts his stethoscope on a patient's chest over the location of the heart and hears an abnormal swishing sound. What condition is the best diagnosis for the patient's condition?

Incompetent cardiac valve

What are the functions of the fibrous pericardium?

It prevents the heart from overfilling with blood, , protects the heart, and anchors the heart to surrounding structures

The interventricular septum forms a dividing wall between the __________.

Left and right ventricles

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

The most muscular chamber of the heart is the __________.

Left ventricle

During systemic circulation, blood leaves the __________.

Left ventricle and flows directly to the aorta

Guided by powerful signaling molecules, the human heart develops from __________.

Mesoderm

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

Pacemaker cells

What would lead to a decrease in heart rate?

Parasympathetic stimulation

The structure just deep to the fibrous pericardium is the __________.

Parietal layer of the serous pericardium

What is the function of the aortic semilunar valve?

Prevents backflow of blood into the left ventricle

What is the function of the pulmonary semilunar valve?

Prevents backflow of blood into the right ventricle

Diastole causes _______.

Relaxation

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 endocardium is composed of __________.

Squamous epithelium

What is the function of the anterior interventricular artery?

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

What is the function of the right marginal artery?

Supplies blood to the lateral right side of the myocardium

What is the function of the circumflex artery?

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

What is cardiac output?

The amount of blood pumped by each ventricle in one minute

Cardiac output is __________.

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

Which structure is superficial to the heart wall and serves to protect the heart, anchor the heart, and prevent the heart from overfilling?

The epicardium

What is the cardiac cycle?

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

What part of the heart is considered the systemic circuit pump?

The left ventricle

Which valve is most often faulty in the heart?

The mitral, or bicuspid, valve

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 which events?

The number of times the heart beats in one minute

What is stroke volume?

The volume of blood pumped by one ventricle with each heartbeat

True or false. In the fetus, blood from the left and right sides of the heart normally mix.

True

What is a difference between cardiac muscle and skeletal muscle?

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

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

Vagus

Where is the mitral (bicuspid) valve located?

Valve between the left atrium and left ventricle

Where is the tricuspid valve located?

Valve between the right atrium and right ventricle