Chapter 20 Mock Exam - The Heart

If a patient's resting cardiac output is 5.6 l/min and on a stress test she elevated her heart rate to a maximum of 176 beats/min with a stroke volume of 115 ml/beat, what is her cardiac reserve? Show your work.

Cardiac reserve = Max CO - rest CO Max CO = HR x SV Max CO = 176 x .115 = 20.2 CR = 20.2 - 5.6

Cardiac Output =

HR x (EDV-ESV)

A patient's ECG recording shows a very long P-R interval. What is the cause of this abnormal wave pattern?

The P wave marks the time of atrial depolarization and the QRS complex signals ventricular depolarization. Between those two events the AV node was excited and the action potential was spread through the conducting tissue to the ventricular myocardium. A prolonged P-R interval signifies an usually slow conduction through the AV node and conducting system, possibly due to insufficient blood flow (ischemia).

Most of the middle layer in the heart wall is composed of... a. cardiac muscle cells. b. chondrocytes. c. epitheliocytes. d. fibrocytes. e. smooth muscle cells.

a. cardiac muscle cells.

The ________ deliver(s) blood to the myocardium. a. coronary arteries b. cardiac veins c. superior vena cava d. carotid arteries e. coronary sinus

a. coronary arteries

What structure is between the right atrium and right ventricle? a. cusp of tricuspid valve b. pulmonary semilunar valve c. aortic semilunar valve d. bicuspid valve e. ligamentum arteriosum

a. cusp of tricuspid valve

Cardiac output can be increased by all of the following except... a. decreasing ejection fraction. b. decreasing end systolic volume. c. increasing stroke volume. d. increasing ejection fraction. e. increasing heart rate.

a. decreasing ejection fraction.

The structure that permits blood flow from the right atrium to the left atrium in the fetal circulation is the... a. foramen ovale b. interatrial septum c. coronary sinus d. fossa ovalis e. ligamentum arteriosus

a. foramen ovale

The pulmonary veins carry blood to the... a. heart. b. lungs. c. brain. d. intestines. e. liver.

a. heart.

The atrioventricular valves permit blood flow... a. in one direction only. b. in both directions. c. in many directions. d. in opposite directions on the right and left. e. from a ventricle to an atrium.

a. in one direction only.

In cardiac muscle, the fast depolarization phase of the action potential is the result of... a. increased membrane permeability to sodium ions. b. increased membrane permeability to potassium ions. c. decreased membrane permeability to calcium ions. d. decreased membrane permeability to sodium ions. e. increased membrane permeability to chloride ions.

a. increased membrane permeability to sodium ions.

Blood returning to the heart from the systemic circuit first enters the... a. right atrium b. right ventricle c. left atrium d. left ventricle e. conus arteriosus

a. right atrium

The adult heart is roughly the size of... a. the liver b. a man's clenched fist c. the gallbladder d. the hand of a 10-year-old e. the brain

b. a man's clenched fist

The first blood vessels to branch from the aorta are the ________ arteries. a. pulmonary b. coronary c. circumflex d. carotid e. subclavian

b. coronary

When the left ventricle contracts, the distance from the apex to the base... a. increases. b. decreases. c. remains unchanged.

b. decreases.

The pulmonary arteries carry blood to the... a. heart. b. lungs. c. brain. d. intestines. e. liver.

b. lungs.

Each of the following factors will increase cardiac output except increased... a. venous return. b. parasympathetic stimulation. c. sympathetic stimulation. d. heart rate. e. force of contraction.

b. parasympathetic stimulation.

What structure is in the tube that leaves the right ventricle to go to the lungs? a. tricuspid valve b. pulmonary semilunar valve c. aortic semilunar valve d. bicuspid valve e. ligamentum arteriosum

b. pulmonary semilunar valve

Blood leaves the right ventricle by passing through the... a. aortic valve b. pulmonary valve c. mitral valve d. tricuspid valve e. bicuspid valve.

b. pulmonary valve

The normal pacemaker of the heart is located in... a. the Purkinje fibers. b. the sinoatrial node. c. the atrioventricular node. d. the wall of the left ventricle. e. both the left and right ventricles.

b. the sinoatrial node.

What is the correct order for the flow of blood entering from the systemic circulation? 1. right atrium 2. left atrium 3. right ventricle 4. left ventricle 5. venae cavae 6. aorta 7. pulmonary trunk 8. pulmonary veins a. 1, 2, 7, 8, 3, 4, 6, 5 b. 1, 7, 3, 8, 2, 4, 6, 5 c. 5, 1, 3, 7, 8, 2, 4, 6 d. 5, 3, 1, 7, 8, 4, 2, 6 e. 5, 1, 3, 8, 7, 2, 4, 6

c. 5, 1, 3, 7, 8, 2, 4, 6

Pacemaker cells isolated from the SA node generate action potentials at ________ beats per minute. a. 20-40 b. 40-60 c. 80-100 d. 100-140 e. 140-180

c. 80-100

During ventricular systole, the... a. atria are contracting. b. blood is entering the ventricles. c. AV valves are closed. d. pressure in the ventricles remains constant. e. pressure in the aorta remains constant.

c. AV valves are closed.

Abnormally slow depolarization of the ventricles would most change the shape of the ________ in an ECG tracing. a. P wave b. T wave c. QRS complex d. P-R interval e. R-T interval

c. QRS complex

The heart is innervated by ________ nerves. a. parasympathetic b. sympathetic c. both parasympathetic and sympathetic d. neither parasympathetic nor sympathetic e. somatomotor

c. both parasympathetic and sympathetic

The cusps (leaflets) of atrioventricular valves attach directly to... a. papillary muscles. b. trabeculae carneae. c. chordae tendineae. d. interatrial septa. e. coronary sulci.

c. chordae tendineae.

The P wave of the electrocardiogram is a signal from... a. the SA node. b. depolarization of the AV node. c. depolarization of the atria. d. repolarization of the atria. e. depolarization of the ventricles.

c. depolarization of the atria.

The visceral pericardium is the same as the... a. mediastinum. b. parietal pericardium. c. epicardium. d. myocardium. e. endocardium.

c. epicardium.

Blood returning to the heart from the pulmonary circuit first enters the... a. right atrium. b. right ventricle. c. left atrium. d. left ventricle. e. conus arteriosus

c. left atrium.

Heart rate is controlled by neurons of the cardiovascular center located in the... a. pons. b. thalamus. c. medulla oblongata. d. hypothalamus. e. higher centers.

c. medulla oblongata.

What structure is connected to the heart wall and the chordae tendineae? a. moderator band b. pectinate muscles c. papillary muscles d. trabeculae carneae e. chordae tendineae

c. papillary muscles

Compared to the right ventricle, the left ventricle has all the following characteristics except... a. has a thicker wall. b. is round in cross section. c. pumps a greater volume. d. works harder. e. produces about four to six times more pressure when it contracts.

c. pumps a greater volume.

Which of the following are involved in the pulmonary circuit? a. superior vena cava, right atrium, left ventricle b. right ventricle, pulmonary veins, aorta c. right ventricle, pulmonary trunk, left atrium d. inferior vena cava, right atrium, aorta e. left ventricle, pulmonary veins, right atrium

c. right ventricle, pulmonary trunk, left atrium

The volume of blood ejected from each ventricle during a contraction is called the a. end-diastolic volume. b. end-systolic volume. c. stroke volume. d. cardiac output. e. cardiac reserve.

c. stroke volume.

Blood flowing into the heart from the venae cavae flows next through the ________ valve. a. mitral b. bicuspid c. tricuspid d. pulmonary semilunar e. aortic semilunar

c. tricuspid

1. Purkinje fibers 2. AV bundle 3. AV node 4. SA node 5. bundle branches The sequence in which excitation would move through this system is... a. 1, 4, 3, 2, 5. b. 3, 2, 4, 5, 1. c. 3, 5, 4, 2, 1. d. 4, 3, 2, 5, 1. e. 4, 2, 3, 5, 1.

d. 4, 3, 2, 5, 1.

Considering the left ventricle, why does isovolumetric ventricular contraction occur during ventricular systole? a. The ventricle needs to pressurize the blood to close the aortic valve. b. Ventricular pressure is greater than atrial pressure so the ventricle cannot eject blood. c. The bicuspid valve needs time to shut before the ventricle can eject blood. d. Aortic pressure is higher than ventricular pressure and the ventricle must pressurize the blood to open the aortic valve. e. The ventricle is still filling with blood and therefore cannot eject blood during this time.

d. Aortic pressure is higher than ventricular pressure and the ventricle must pressurize the blood to open the aortic valve.

End-systolic volume is defined as the... a. amount of blood a ventricle ejects per cycle. b. amount of blood which backflows into a ventricle. c. amount of blood remaining in an atrium after atrial systole. d. amount of blood remaining in a ventricle after contraction. e. stroke volume multiplied by the heart rate.

d. amount of blood remaining in a ventricle after contraction.

The earlike extension of the atrium is the... a. ventricle. b. coronary sinus. c. coronary sulcus. d. auricle. e. atricle.

d. auricle.

An increase in the rate of action potentials from baroreceptors will trigger a reflex to... a. increase heart rate. b. decrease heart rate. c. decrease blood pressure. d. both decrease heart rate and decrease pressure. e. both increase heart rate and increase pressure

d. both decrease heart rate and decrease pressure.

What tiny structure connects the aorta and the pulmonary trunk? a. bicuspid valve b. pulmonary semilunar valve c. aortic semilunar valve d. ligamentum arteriosum e. tricuspid valve

d. ligamentum arteriosum

Contractions of the papillary muscles... a. close the atrioventricular valves. b. close the semilunar valves. c. eject blood from the ventricles. d. prevent the atrioventricular valves from reversing into the atria. e. eject blood from the atria into the ventricles.

d. prevent the atrioventricular valves from reversing into the atria.

The pulmonary semilunar valve prevents backward flow into the... a. aorta. b. pulmonary trunk. c. pulmonary veins. d. right ventricle. e. left atrium.

d. right ventricle.

The T wave on an ECG tracing represents... a. atrial depolarization. b. atrial repolarization. c. ventricular depolarization. d. ventricular repolarization. e. ventricular contraction.

d. ventricular repolarization.

Intercalated discs serve to transfer ________ from cell to cell. a. ionic currents b. action potentials c. the force of contraction d. electrical signals e. All of the answers are correct

e. All of the answers are correct

A heart murmur might be caused by... a. aortic valve insufficiency. b. mitral valve insufficiency. c. pulmonic valve insufficiency. d. swirling of blood in the ventricle. e. All of the answers are correct.

e. All of the answers are correct.

Stroke volume depends on... a. end diastolic volume. b. the contractility of the ventricle. c. the pressure required to pump blood into the aorta. d. venous return of blood to the heart. e. All of the answers are correct.

e. All of the answers are correct.

The right atrium receives blood from the... a. coronary sinus. b. superior vena cava. c. inferior vena cava. d. systemic circuit. e. All of the answers are correct.

e. All of the answers are correct.

Cardiac muscle cells and skeletal muscle cells differ in a few ways. Which of the following is not one of them? a. Cardiac muscle cells are smaller in size. b. Cardiac muscle cells have a single, centered nucleus. c. Cardiac muscle cells branch. d. Skeletal muscle cells lack intercalated discs. e. Cardiac muscle cells lack transverse tubules.

e. Cardiac muscle cells lack transverse tubules.

The bicuspid or mitral valve is located... a. in the opening of the aorta. b. in the opening of the pulmonary trunk. c. where the venae cavae join the right atrium. d. between the right atrium and right ventricle. e. between the left atrium and left ventricle.

e. between the left atrium and left ventricle.

With each ventricular systole... a. blood pressure remains steady. b. the ventricles fill with blood. c. blood pressure decreases. d. cardiac output decreases. e. blood pressure increases.

e. blood pressure increases.

If the pacemaker cells in the SA node become more permeable to potassium ions, the a. heart rate will increase. b. heart rate will decrease. c. cells will depolarize. d. cells will hyperpolarize. e. heart rate will decrease and cells will hyperpolarize.

e. heart rate will decrease and cells will hyperpolarize.