Heart

In what order would excitation move through the conducting system of the heart? 1. Purkinje fibers 2. AV bundle 3. AV node 4. SA node 5. bundle branches A) 4, 3, 2, 5, 1 B) 3, 5, 4, 2, 1 C) 1, 4, 3, 2, 5 D) 4, 2, 3, 5, 1 E) 3, 2, 4, 5, 1

A) 4, 3, 2, 5, 1

A patient has an end-diastolic volume of 125 ml. A heart attack has weakened her left ventricle so it can pump a stroke volume of only 40 ml. Calculate her end-systolic volume. A) 85 ml B) 3.1 ml C) 5000 ml D) 165 ml E) There is not enough data given to calculate the end-systolic volume

A) 85 ml

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

Artery is to ______ as vein is to ______. A) efferent; afferent B) afferent; efferent C) toward; away D) afferent; away E) efferent; away

A) efferent; afferent

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

Excess fluid in the _____ causes cardiac tamponade. A) pericardial cavity B) visceral pericardium C) apex of the heart D) left ventricle E) both atria

A) pericardial cavity

The right ventricle pumps blood to the A) right and left lungs B) left ventricle C) left atrium D) aorta E) right atrium

A) right and left lungs

Cardiac output is increased by A) sympathetic stimulation B) increased end systolic volume C) decreased end diastolic volume D) decreased venous return E) inhibiting the atrial reflex

A) sympathetic stimulation

The first heart sound is heard when the A) AV valves open B) AV valves close C) semilunar valves close D) atria contract E) blood enters the aora

B) AV valves close

At a heart rate of 60 bpm, a cardiac cycle lasts A) 60 seconds B) 60 milliseconds C) 1 second D) 370 milliseconds E) 630 milliseconds

C) 1 second

Calculate cardiac output if the heart rate is 125 bpm, the end-diastolic volume is 130 ml, and the end-systolic volume is 40 ml A) 21,250 ml/min B) 16,250 ml/min C) 11,250 ml/min D) 195 ml/min E) 200 ml/min

C) 11, 250 ml/min

The following are structural components of the conduction system of the heart. 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

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 above

Which of the following would increase heart rate? A) increased sympathetic stimulation of SA node B) decreased parasympathetic stimulation of nodal fibers C) increased levels of epinephrine D) faster depolarization of the pacemaker potential E) All of answers are correct

E) All of the answers are correct

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

The right pulmonary veins carry ____ blood to the _____. A) deoxygenated; left atrium B) oxygenated; right lung C) deoxygenated; superior vena cava D) deoxygenated; right atrium E) oxygenated; left atrium

E) oxygenated; left atrium

The long plateau phase of the cardiac muscle action potential is due to A) movement of fewer sodium ions across the cell membrane B) calcium channels remaining open C) increased membrane permeability to potassium ion D) decrease in the amount of calcium diffusing across the membrane E) increased membrane permeability to sodium ions

B) calcium channels remaining open

Pacemaker cells in the SA node A) have a well-defined resting potential B) can spontaneously depolarize C) also contract with the rest of the cells in the heart wall D) are special neurons that convey signals from the brain to the heart E) All of the answers are correct

B) can spontaneously depolarize

The first blood vessels to branch from the aorta are the ____ arteries A) pulmonary B) coronary C) circumflex D) carotid E) subclavian

B) coronary

The pulmonary arteries carry blood to the A) heart B) lungs C) brain D) intestines E) liver

B) lungs

When the semilunar valves close, the AV valves then A) close B) open C) make the third heart sound D) contract E) prolapse

B) open

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

If the connection between the SA node and the AV node becomes blocked, A) the ventricles will beat faster B) the ventricles will beat more slowly C) the ventricular beat will remain unchanged D) cardiac output will increase E) the atria will contract more forcefully

B) the ventricles will beat more slowly

The following is a list of vessels and structures that are associated with the heart. 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

During ventricular systole, the A) atria are contracting B) blood is entering the ventricle C) AV valves are closed D) pressure in the ventricular 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 _____ valve prevents backward flow into the left atrium A) semicaval B) semilunar C) bicuspid D) tricuspid E) pulmonic

C) bicuspid

The cusps (leaflets) of atrioventricular valves attach directly to A) papillary muscles B) trabeculae carneae C) chordae tendinae D) interatrial septa E) coronary sulci

C) chordae tendinae

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

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

In the middle of the thoracic cavity is a region occupied by the heart, great vessels, thymus, esophagus, and trachea called the A) pleural space B) pericardial space C) mediastinum D) cardiac notch E) ventral cavity

C) mediastinum

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

Coronary veins empty into the A) left atrium B) left ventricle C) right atrium D) right ventricle E) conus arteriosus

C) right atrium

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

As a result of the long refractory period in the cardiac action potential, cardiac muscle cannot exhibit A) tonus B) treppe C) tetany D) recruitment E) fatigue

C) tetany

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

Considering the left ventricle, why does the 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 ventricle must pressurize the blood to open the aortic valve

Depolarization of the ventricles is represented on an electrocardiogram by the A) P wave B) T wave C) S wave D) QRS complex E) PR complex

D) QRS complex

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