Anatomy 21

The chambers of the heart empty during: A) diastole. B) atrial systole. C) ventricular systole. D) maximum contraction. E) None of the answers are correct.

c

The heart wall is composed of ________ layers of tissues. A) 1 B) 2 C) 3 D) 4 E) 5

c

Pulmonary arteries carry oxygen-deprived blood.

true

The SA node is located in the upper wall of the right atrium.

true

Blood vessels traveling away from the heart are: A) arterioles. B) venules. C) arteries. D) capillaries. E) All of the answers are correct.

c

The bicuspid valve is the exit of the right ventricle.

false

The pulmonary veins bring blood from the lungs back to the heart.

true

Cardiac muscle cells do not need ________ to contract. A) calcium B) potassium C) nervous stimulation D) ATP E) sodium

c

Blood that is transported to and from all of the tissues of the body with the exception of the lungs is in the A) systemic circuit. B) venous circuit. C) portal circuit. D) pulmonary circuit. E) arterial circuit.

a

During most of ventricular diastole, the: A) the ventricles are filling. B) ventricles are contracting. C) atria are contracting. D) pressure in the ventricles does not change. E) AV valves are closed.

a

During one cardiac cycle the ventricles spend most of their time in: A) diastole. B) contraction. C) fibrillation. D) systole. E) None of the answers are correct.

a

During their period of systole, the inner volume of the atrial chambers: A) decreases. B) does not change. C) remains the same, but the auricles enlarge rapidly. D) increases, as does the volume in the auricles. E) None of the answers are correct.

a

How would the heart rate be affected if there were a blockage of the AV node? A) The electrical stimuli from the SA node would be normal, but the rate of contraction would slow or be irregular. B) The heart rate would slow dramatically, and become extremely irregular, contracting only when the ventricles became overfilled. C) The heart rate would be unaffected. D) The heart would cease to contract. E) The heart rate would increase.

a

If a small blood clot passes through the heart and heart vessels, where is it most likely to cause damage if it becomes immobilized? A) the left coronary artery B) the right atrial chamber C) the left ventricle D) the aorta E) Severe damage could occur if a small blood clot became immobilized at any of these positions.

a

Nodal activity of the heart may be influenced or modified by A) the autonomic nervous system. B) the somatomotor cortex. C) hormones secreted by the lungs. D) enzymes released from the kidney. E) either the SA node or the AV node, but no other system.

a

The ability of the blood to supply oxygen and remove carbon dioxide from the tissues depends upon A) the ability of the blood to remain in constant motion. B) the number of white blood cells in the circulation. C) the rate at which platelets are manufactured. D) the osmotic balance, as controlled by the kidneys. E) the diameter of the capillaries.

a

The broad, superior portion of the heart is the: A) base. B) apex. C) anterior surface. D) pulmonary surface. E) sternocostal surface.

a

The contraction of any one cardiac muscle fiber: A) will cause the contraction of several others. B) will immediately trigger an all-or-none response in all other cardiac fibers. C) will cause the rate of heart muscle contraction to increase. D) will stimulate the electrical conduction system of the heart. E) None of the answers are correct.

a

The heart has the unique ability to change its workload. On average the heart can pump between ________ and ________ liters of blood per minute. A) 5; 30 B) 1; 3 C) 5; 50 D) 2; 20 E) 10; 20

a

The left atrium receives blood from the: A) pulmonary veins. B) aorta. C) pulmonary trunk. D) coronary arteries. E) mitral valve.

a

The main pacemaker region of the heart is: A) in the wall of the right atrium. B) in the interventricular septum. C) electrically active nodal tissue located in the wall of the left ventricle. D) able to cause the muscle to begin to contract at the apex. E) able to cause the atria and ventricles to contract simultaneously.

a

The moderator band is located in the: A) right ventricle. B) left ventricle. C) right atrium. D) interventricular sulcus. E) left atrium.

a

The most serious place for a blockage of a coronary artery is A) the left coronary artery. B) the posterior interventricular artery. C) left anterior descending artery. D) the circumflex branch of the left coronary artery. E) the right marginal branch of the right coronary artery.

a

The serous membrane lining the pericardial cavity is the A) pericardium. B) pleura. C) myocardium. D) mediastinum. E) endocardium.

a

In terms of time, at rest one cardiac cycle lasts A) about a half second. B) a little under 1 second. C) about 1.5 seconds. D) 5 seconds. E) None of the answers are correct.

b

Papillary muscles of the right ventricle receive a signal to contract from (the): A) bundle branches. B) moderator band. C) Purkinje fibers. D) AV node. E) None of the answers are correct.

b

Prominent muscular ridges that run along the inner surface of the auricle and across the adjacent atrial wall are the A) papillary muscles. B) pectinate muscles. C) chordae tendineae. D) trabeculae carneae. E) foramen ovale.

b

The innermost layer of the heart wall is the: A) myocardium. B) endocardium C) connective tissue. D) fibrous pericardium. E) parietal and visceral layers of the epicardium.

b

The reinforcing layer of the pericardium is the ________ layer. A) parietal B) fibrous C) epicardial D) sutural E) visceral

b

The superior end of the right ventricle near the pulmonary valve is called (the): A) auricle. B) conus arteriosus. C) ligamentum arteriosum. D) pulmonary trunk. E) All of the answers are correct.

b

The tough structure that surrounds the heart and helps reinforce and maintain position of the heart is the A) aorta. B) pericardial sac. C) mediastinum. D) pleural cavity. E) epicardium.

b

When a clot forms in a coronary vessel and obstructs blood flow to the muscle, the condition is referred to as a(n) A) angina pectoris. B) coronary thrombosis. C) pulmonary embolism. D) myocardial infarction. E) None of the answers are correct.

b

Which of the following conditions would cause the amount of blood entering the ascending aorta with each contraction of the heart to increase? A) Stimulation by the sympathetic nervous system would accompany this change. B) The amount of blood entering the right atrium of the heart was increased. C) The atrioventricular valves would not close. D) The amount of blood sent to the lungs for oxygenation would decrease. E) The heartbeat would be speeded up by the parasympathetic nervous system.

b

Which of the following is a major component of the conduction system located in the interventricular septum? A) Purkinje fibers B) bundle branches C) SA node D) AV node E) None of the answers are correct.

b

Which of the following is an incorrect association? A) semilunar—pulmonary valve B) atrioventricular—aortic valve C) atrioventricular—tricuspid valve D) atrioventricular—mitral valve E) None of the answers are correct.

b

Which of the following is true of the contraction of the heart? A) The contractions do not occur in any specific repeatable sequence each time. B) Cardiac contractions are coordinated by specialized conductive cardiac muscle fibers. C) The ventricles contract first, followed by the atria. D) The muscle obtains the beat from the pacemaker region exclusively. E) None of the answers are correct.

b

Externally the posterior and inferior portions of the left ventricle form the: A) sternocostal surface. B) left border. C) diaphragmatic surface. D) right border. E) superior border.

c

The connective tissues of the heart: A) do not join the muscle fibers to the fibrous skeleton of the heart. B) consist only of many dense collagen fibers. C) provide a strong fibrous cross-linkage system wrapping adjacent muscle cells together. D) All of the answers are correct. E) None of the answers are correct.

c

The coronary artery found under the right atrium is (the) A) posterior interventricular artery. B) LAD. C) right coronary artery. D) circumflex artery. E) None of the answers are correct.

c

The most important factor in ensuring that blood moves in correct order through the heart is (the): A) location of the main electrical conduction node. B) coordination of the timing of atrial and ventricular systole. C) pressure of blood in each of the chambers at any given time. D) strength of the contraction of the different parts of the myocardium. E) None of the answers are correct.

c

The thick muscular partition that separates the two ventricles entire heart is the: A) left ventricle. B) right ventricle. C) interventricular septum. D) right atrium. E) left atrium.

c

Valves of the heart open and close due to: A) timing sequences. B) contraction of papillary muscles. C) pressure changes. D) electrical signals. E) None of the answers are correct.

c

Which of the chambers of the heart can generate the greatest pressure? A) the right ventricle B) the left atrium C) the left ventricle D) the right atrium E) Both ventricles create greater pressures simultaneously than do the atria.

c

Which of the following is supplied with blood by the left anterior descending artery? A) right atrium B) right ventricle C) left ventricle D) posterior heart wall E) the conducting system

c

Which of the following is true of the coronary arteries? A) They open and close in pulsation with the contraction and relaxation of the heart ventricles. B) Together they supply part of the heart muscle with oxygen. C) They originate at the base of the aorta and are the first branches off this vessel. D) They branch off the pulmonary veins. E) None of the answers are correct.

c

At rest the heart rate is usually ________ by parasympathetic control. A) increased B) unchanged C) shut down D) decreased E) None of the answers are correct.

d

Cardiac muscle cells obtain energy almost exclusively through: A) glycolysis. B) protein stores. C) anaerobic pathways. D) aerobic respiration. E) the Krebs cycle.

d

Cardiac muscle differs from other muscle tissue in: A) having larger sized fibers than other striated muscles. B) having striations. C) having fewer mitochondria. D) having fibers connected to one another at intercalated discs. E) no ways; it is not unusual.

d

Grooves on the external surface of the heart that divide the right and left ventricles include the 20) A) atrioventricular sulcus. B) coronary fissure. C) lateral sulcus. D) anterior interventricular sulcus. E) interventricular septum.

d

Pacemaker cells of the SA node depolarize about: A) 120-140 times per minute. B) 40-50 times per minute. C) 60-70 times per minute. D) 80-100 times per minute. E) None of the answers are correct.

d

Structures in the heart that carry electrical signals from the SA node to the AV node are called A) the chordae tendineae. B) bundle branches. C) Purkinje fibers. D) internodal pathways. E) None of the answers are correct.

d

The fibrous skeleton of the heart is located: A) forming the atria and ventricles of the heart. B) in the wall of the pericardial sac. C) covering the outer surface of the heart. D) surrounding the heart valves. E) All of the answers are correct.

d

The phase of the cardiac cycle during which each chamber contracts and pushes blood into the next structure is A) relaxation. B) diastole. C) ejection. D) systole. E) None of the answers are correct.

d

The visceral pericardium is also called the: A) fibrous pericardium. B) pericardial sac. C) parietal pericardium. D) epicardium. E) pericardial cavity.

d

Which of the following empty directly into the right atrium? A) middle cardiac vein B) great cardiac vein C) small cardiac vein D) anterior cardiac veins E) None of the answers are correct.

d

Blood is supplied to the muscle of the heart through the: A) pulmonary arteries. B) cardiac sinus. C) interventricular septum. D) conus arteriosus. E) coronary arteries.

e

Blood travels from the left atrium to the left ventricle through the: A) semilunar valve. B) tricuspid valve. C) conus arteriosus. D) fossa ovalis. E) mitral valve.

e

One of the major differences between skeletal muscle and cardiac muscle is that cardiac muscle A) needs Ca2+ to contract. B) has myosin and actin. C) has a very large sarcoplasmic reticulum. D) is striated. E) lacks triads.

e

The anterior and posterior interventricular sulci on the outside of the heart contain A) grooves. B) fat. C) coronary arteries. D) cardiac veins. E) All of the answers are correct.

e

The fibrous skeleton of the heart functions to: A) maintain the shape of the heart. B) help distribute the force of contraction of the heart. C) physically isolating the atrial muscle cells from the ventricular muscle cells. D) reinforcing the heart valves. E) All of the answers are correct.

e

The left ventricle pumps blood into the: A) vena cava. B) pulmonary arteries. C) pulmonary veins. D) pulmonary semilunar valves. E) aorta.

e

The right ventricle is associated exclusively with which of the following? A) aorta B) mitral valve C) trabeculae carneae D) papillary muscles E) pulmonary trunk

e

The right ventricle: A) sends blood out through the aortic semilunar valve. B) pumps blood out of the heart to the systemic circuit. C) is connected to the pulmonary veins. D) receives blood from the left atrium through the tricuspid valve. E) has thinner muscular walls than does the left ventricle.

e

The wall between the atria is called the: A) coronary sulcus. B) cardiac septum. C) interchamber septum. D) interventricular septum. E) interatrial septum.

e

Which of the following valves is assisted in functioning by the papillary muscles? A) mitral valve B) right atrioventricular valve C) bicuspid valve D) tricuspid valve E) All of the answers are correct.

e

The Purkinje cells are tightly bound together to form the AV bundle.

false

The pacemaker of the heart is the AV node.

false

The pulmonary trunk carries blood to the body cells.

false