Ch. 12 Anatomy

Which cranial nerve carries parasympathetic preganglionic fibers to small ganglia near the heart?

Vagus (N X)

Which of the following reflexes affects stroke volume?

Ventricular reflex

Which of the following is NOT part of the conduction system of the heart?

AV valve

Which of the following is an effect of ACh on the heart?

Decreases contractility

What would happen to filling time if heart rate increases?

Filling time decreases

Before synthetic drugs were available, which of the following substances was used to stimulate heart function?

Glucagon

The duration of ventricular diastole (filling time) depends primarily on which of the following factors?

Heart rate

In which of the following clinical conditions do cardiac muscle cells become extremely excitable?

Hypercalcemia

What would happen to the heart if you cut the vagus nerve?

Increases heart rate

Which of the following blood vessels returns deoxygenated blood to the right atrium from the trunk, viscera, and lower limbs?

Inferior vena cava

What attaches the pulmonary trunk to the aortic arch?

Ligamentum arteriosum

Which cardiac conducting system structures are responsible for establishing the rate of cardiac contraction?

Pacemaker (nodal) cells

Depolarization of the ventricles on the EKG is called which of the following?

QRS complex

Which event in a cardiac muscle cell's action potential lasts about 75 msec and ends with closure of potassium channels?

Repolarization

The pacemaker cells of the heart are located in the __________.

SA node

Which of the following is the correct order in which the electrical impulse travels through the heart in the conduction system?

SA node, AV node, AV bundle, bundle branches, Purkinje fibers

Which of the following is the correct flow of blood?

SVC, right atrium, tricuspid valve, right ventricle, pulmonary semilunar valve, pulmonary trunk

Which of the following heart sounds occurs when the semilunar valves close?

Second heart sound

Which part of the conducting system is located in the posterior wall of the right atrium?

Sinoatrial (SA) node

Any chamber of the heart squeezes blood into an adjacent chamber or into an arterial trunk during which event?

Systole

What cannot happen in cardiac muscles resulting from a refractory period that continues until relaxation is under way?

Tetanus

Which of the following aspects of contraction cannot occur in a normal cardiac muscle cell?

Tetanus

Drugs such as digitalis result in an increase in the force of cardiac contractions by ___________.

increasing Ca2+ concentration within cardiac muscle cells

Systemic circulation is to the body as the _______________ circulation is to the heart.

oxygenated

The heart is surrounded by the

pericardial cavity

What ion is involved in hyperkalemia and hypokalemia?

potassium

During the cardiac cycle, the pressure within each chamber ___________.

rises during systole and falls during diastole

Which of the following events does NOT occur during ventricular systole?

semilunar valves are closed

The ANS includes a sympathetic division and a parasympathetic division, which commonly have opposite effects. What is the other system of the efferent division that has voluntary control?

somatic nervous system

Which of the following would increase cardiac output (CO)?

stimulation of the sympathetic nervous system

The amount of blood ejected by a ventricle during a single beat is called __________.

stroke volume

Contraction of the ventricles is called __________.

systole

After the stimulus for a contraction is generated at the SA node, it must be distributed so that ___________.

the atria contract together before the ventricles

When listening to the heart with a stethoscope, the second heart sound, the "dupp" results from _________.

the closing of the semilunar valves

Blood cannot begin moving into the arterial trunks until __________.

ventricular pressures exceed arterial pressures

Which heart valve prevents regurgitation of blood into the left atrium?

mitral valve

The muscle layer of the heart is the ________.

myocardium

Which of the following is the correct equation to calculate cardiac output?

CO = HR x SV

The following events occur during the action potential of a contractile cardiac muscle cell. In which order do they occur?

Calcium releases from the sarcoplasmic reticulum. Calcium channels close. Calcium channels open. Sodium channels open. Potassium channels open.

Which of the following structural features is composed of connective tissue fibers connected to cone-shaped projections on the inner surface of the ventricle?

Chordae tendineae

The cardiac veins of the heart return venous blood to which of the following structures?

Coronary sinus

Which of the following coronary blood vessels drains directly into the right atrium of the heart?

Coronary sinus

Which of the following surface anatomical features is a deep groove that marks the border between the atria and ventricles?

Coronary sulcus

Which layer of the heart wall is also known as the visceral pericardium?

Epicardium

Which of the following events occur when the ventricles are relaxed?

The AV valves are open, and the semilunar valves are closed.

What does the Q-T interval indicate?

The time required for the ventricles to undergo a single cycle of depolarization and repolarization.

Sympathetic blocking agents have what effect on the heart?

They slow heart rate.

Which of the following heart sounds are associated with atrial contraction and with blood flowing into the ventricles and not with valve action?

Third and fourth heart sounds

Individuals can survive quite normally when their atria no longer function because of the relatively minor contribution ______ makes to ventricular volume.

atrial systole

Where is the mitral valve found?

between the left atria and left ventricle

What connects each AV valve to the papillary muscles?

chordae tendineae

The first heart sound ("lubb") is produced as the atrioventricular valves ________ and the semilunar valves ________.

close; open

Which of the following supplies blood to the muscle tissue of the heart?

coronary arteries

The visceral pericardium is located where?

covering the outer surface of the heart

Medications that act by decreasing Ca2+ concentration in extracellular fluids surrounding cardiac muscle cells would __________.

decrease stroke volume (SV)

Each cardiac muscle cell is bound to its neighboring cells at sites called ________.

intercalated discs