The AV node delay:

a. Allows the atria and ventricles to depolarize and contract as a unit.

b. Allows the two ventricles to depolarize and contract separately.

c. Allows the atria and ventricles to depolarize and contract separately.

d. Speeds up the impulse transmission from the atria to the ventricles.

A birth defect called transposition of great vessels results in the pulmonary trunk emanating from the left ventricle and the aorta stemming from the right ventricle.

Which ventricle is thicker-walled, and why?

A birth defect called transposition of great vessels results in the pulmonary trunk emanating from the left ventricle and the aorta stemming from the right ventricle.

Predict the potential effects of this birth defect.

Predict which would be more damaging to long-term survival: a blood clot lodged in the right coronary artery or one in the left coronary artery. Explain.

Common findings in heart failure are fluid retention by the kidneys and stimulation of the heart by the sympathetic nervous system. How would both of these findings help the body to compensate for the failing heart?

You are an athletic trainer who is working with someone planning to run a marathon. Your trainee tells you to give him a workout that will make his heart 'beat faster than ever before.' What do you tell him about the effects of too rapid a heart rate?

A newer drug, ivabradine, lowers the heart rate by blocking the nonselective HCN cation channels. Why would this action decrease the heart rate? Would this drug have an effect on pacemaker cells, contractile cells, or both? Explain.

Mr. Watson has been diagnosed with mitral insufficiency, or a malfunctioning mitral valve, which causes the valve to not close properly. Predict the signs and symptoms you might expect from a disease of this valve. What would happen to the patient's stroke volume and cardiac output? Explain. What might help improve his cardiac output?

An experimental toxin makes the refractory period of cardiac muscle cells equal in length to that of skeletal muscle fibers. Predict the consequences of this toxin.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

The heart is located in the mediastinum slightly to the left of the midline.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

The heart consists of two superior ventricles and two inferior atria.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Arteries always carry oxygenated blood away from the heart, and veins always carry deoxygenated blood toward the heart.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

The pulmonary circuit delivers blood from the right side of the heart to the lungs to become oxygenated.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

The heart plays a role in the regulation of blood pressure and secretes the hormone atrial natriuretic peptide.

The pericardial cavity is located between:

a. The parietal pericardium and the fibrous pericardium.

b. The fibrous pericardium and the myocardium.

c. The parietal pericardium and the visceral pericardium.

d. The epicardium and the endocardium.

Which of the following statements is true?

a. The tricuspid valve is located between the right atrium and the right ventricle.

b. The mitral valve is located between the pulmonary veins and the left atrium.

c. The pulmonary valve is located between the pulmonary artery and the pulmonary veins.

d. The aortic valve is located between the right ventricle and the aorta.

Match the following terms with the correct definition.

____ Auricle      

____ Aorta      

____ Coronary sinus       

____ Papillary muscle      

____ Fossa ovalis     

____ Pectinate muscle      

____ Venae cavae      

____ Pulmonary trunk      

____ Chordae tendineae      

____ Pulmonary veins 

a. Drainage point for the coronary veins

b. Extensions that attach papillary muscles to valves

c. Remnant of a hole present in the fetal interatrial septum

d. Two largest veins of the systemic circuit

e. Flaplike extension from the right or left atrium

f. Finger-like projections of ventricular muscle

g. Main artery of the pulmonary circuit

h. Veins that drain the pulmonary circuit

i. Largest artery of the systemic circuit

j. Ridges of muscle in the atria

Fill in the blanks: The coronary arteries are the first branches off the ________. The right coronary artery becomes the ________ on the posterior side of the heart. The left coronary artery branches into the ________ and the ________.

How do pacemaker cardiac muscle cells differ from contractile cardiac muscle cells? What is autorhythmicity?

Cardiac muscle cells are joined by structures called:

a. T-tubules.

b. tight junctions.

c. sarcoplasmic reticulum.

d. intercalated discs.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

The rapid depolarization phase of the contractile cell action potential is due to the opening of voltage-gated potassium ion channels.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Pacemaker cells lack a distinct plateau phase.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

The plateau phase in contractile cells is due to the influx of calcium ions through calcium ion channels.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

The repolarization phase of the contractile cell is due to the potassium ions rushing into the cell through potassium ion channels.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Open sodium ion channels cause hyperpolarization in pacemaker cells, which triggers HCN channels to open and begins a new action potential.

What are the effects of the plateau phase of the contractile cell action potential?

The ______ is the primary pacemaker of the heart.

a. Atrioventricular node

b. sinoatrial node

c. Purkinje fiber system

d. Atrioventricular bundle

Explain what each of the following terms represents on an electrocardiogram (ECG).

a. P wave

b. QRS complex

c. T wave

d. P-R interval

e. S-T segment

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Systole is the contraction portion of the cardiac cycle and diastole is the relaxation portion.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Atrial systole is responsible for ejecting most of the blood into the ventricles during the ventricular filling phase of the cardiac cycle.