Ch. 21: The Cardiovascular System: The Heart

Cardiac pacemaker cells of the SA node depolarize and theoretically generate a resting heart rate of approximately ________. A) 60-70 beats per minute B) 55-65 beats per minute C) 80-100 beats per minute D) 45-55 beats per minute E) 110-120 beats per minute

80-100 beats per minute

The cardiac skeleton of the heart functions to ________. A) provide elasticity that helps return the heart to its original shape after each contraction B) physically isolating the atrial muscle cells from the ventricular muscle cells C) help distribute the force of contraction of the heart D) reinforcing the heart valves E) All of the answers are correct.

A) provide elasticity that helps return the heart to its original shape after each contraction B) physically isolating the atrial muscle cells from the ventricular muscle cells C) help distribute the force of contraction of the heart D) reinforcing the heart valves ALL THE ABOVE

________ release produces a decrease in both the heart rate and force of contraction through the stimulation of muscarinic receptors on nodal cells and contractile cells. A) Dopamine B) Acetylcholine (ACh) C) Serotonin D) Norepinephrine (NE) E) Cholecystokinin

Acetylcholine (ACh)

Which event typically occurs at the start of a cardiac cycle? A) Ventricular blood pressure drops until reverse blood flow pushes the cusps of the semilunar valves together. B) Atrial contraction forces a small amount of blood into the relaxed ventricles. C) The semilunar valves open and blood is ejected. D) Ventricular contraction pushes the atrioventricular valves closed. E) The ventricles fully contract.

Atrial contraction forces a small amount of blood into the relaxed ventricles.

Which event occurs during the first phase of ventricular systole? A) Chordae tendineae are loose. B) Semilunar valves are open . C) The volume of the ventricles changes dramatically. D) Blood exits from the ventricles. E) Atrioventricular valves are closed.

Atrioventricular valves are closed

________ is the term used to indicate a heart rate that is slower than normal. A) Cardiac tamponade B) Bradycardia C) Angina D) Tachycardia E) Coronary ischemia

Bradycardia

The exchange of oxygen and carbon dioxide in the cardiovascular system occurs in which vessels? A) veins B) arteries C) capillaries D) venules E) arterioles

Capillaries

Which of the following is TRUE regarding contractions of the heart? A) The ventricles contract first, followed by the atria. B) The contractions do not occur in any specific or precise sequence each time. C) Cardiac muscle tissue contracts under neural stimulation. D) The rate of cardiac contractions are established by the conducting fibers. E) Cardiac contractions are coordinated by specialized conducting cells that distribute the stimulus to cardiac muscle cells.

Cardiac contractions are coordinated by specialized conducting cells that distribute the stimulus to cardiac muscle cells.

Which element of the fibrous pericardium stabilizes the position of the heart and associated vessels within the mediastinum? A) reticular fibers B) collagen fibers C) skeletal muscle D) elastic fibers E) cartilage

Collagen fibers

The visceral pericardium is also called the ________. A) endocardium B) parietal pericardium C) epicardium D) myocardium E) fibrous pericardium

Epicardium

Cardiac muscle cells differ from skeletal muscle fibers in that the cardiac muscle cells are uniquely interconnected by (the) ________. A) sarcoplasmic reticulum B) Z discs C) gap junctions D) intercalated discs E) T tubules

Intercalated discs

The primary function of the pericardial fluid is to provide ________ between the pericardial membranes. A) friction B) impulse stimulation C) pressure D) perforation E) lubrication

Lubrication

The ________ carries blood to and from the gas exchange surfaces of the lungs. A) arterial circle of Willis B) pulmonary circuit C) infundibular circuit D) systemic circuit E) hepatic portal circuit

Pulmonary circuit

Which heart structure receives blood from the systemic circuit? A) left ventricle B) pulmonary veins C) right ventricle D) left atrium E) right atrium

Right Atrium

The rapidly depolarizing cells, called pacemaker cells, are found in the ________, which is embedded in the posterior wall of the right atrium. A) right bundle branch B) AV node C) left bundle branch D) intermodal pathways E) SA node

SA node

Blood that is moved to and from all of the tissues of the body (with the EXCEPTION of the lungs) is transported in the ________. A) infundibular circuit B) pulmonary circuit C) systemic circuit D) hepatic portal circuit E) arterial circle of Willis

Systemic circuit

Which of the following is TRUE of the coronary arteries? A) They drain into the right atrium inferior to the opening of the inferior vena cava. B) Together they supply a small portion of the cardiac muscle with oxygen. C) They originate at the base of the ascending aorta and are the first branches off this vessel. D) They transport blood directly into the ascending aorta. E) Blood pressure in these vessels is the lowest found anywhere in the systemic circuit.

They originate at the base of the ascending aorta and are the first branches off this vessel.

The pericardial cavity is actually ________. A) a potential space B) a large space C) filled with mucin D) contains 150+ mL of pericardial fluid E) increases friction between opposing membranes

a potential space

Which describes the endocardium? a. Has single layer of epithelium b. Has layer of areolar connective tissue c. Epithelial cells are squamous d. Epithelial cells are cuboidal e. Has layer of smooth muscle tissue A) a, b, c B) a, b, d C) a, d, e D) a, b, c, e E) a, c, e

a- has single layer of epithelium b- has layer of areolar connective tissue c- epithelial cells are squamous

Which of these statements can be used to characterize blood flow in the human body? a. There is a unidirectional blood flow. b. Arteries always carry oxygenated blood. c. Veins always carry deoxygenated blood. d. Arteries always carry blood away from the heart. e. Veins always carry blood toward the heart. A) a, c, d, e B) a, b, c, d, e C) a, d, e D) b, c, d, e E) a, b, e

a- there is unidirectional blood flow d- arteries always carry blood away from the heart e- veins always carry blood toward the heart

Which of the following associations is correct? A) baroreceptors-sensitivity to dissolved gas concentrations B) acetylcholine-muscarinic receptors on nodal cells and contractile cells C) parasympathetic nervous system-cardiac nerves D) norepinephrine-alpha receptors on nodal cells and contractile cells E) sympathetic nervous system-vagus nerves

acetylcholine-muscarinic receptors on nodal cells and contractile cells

Which of the following conditions would cause an increase in the heart rate? A) activation of the parasympathetic nervous system B) acetylcholine stimulation of nodal cells and contractile cells C) activation of the sympathetic nervous system D) decreased blood concentration of carbon dioxide and increased blood pressure E) decreased blood concentration of oxygen and increased blood pressure

activation of the sympathetic nervous system

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

aerobic respiration

There are many interconnections between the arterial branches of the coronary circulation, which function to maintain a constant blood supply to the muscle of the heart. These connections are called ________. A) syncytium B) intercalation C) anastomoses D) prolapse E) autorhythmicity

anastomoses

Which of the following vessels drains the anterior surface of the right ventricle and empties directly into the right atrium? A) middle cardiac vein B) great cardiac vein C) anterior cardiac veins D) small cardiac vein E) posterior veins of left ventricle

anterior cardiac veins

Blood exiting the left ventricle must pass through the ________ valve. A) left atrioventricular (mitral) B) pulmonary C) right atrioventricular (tricuspid) D) bicuspid E) aortic

aortic

The diaphragm is attached to the inferior, pointed tip of the heart, called the ________, which points laterally. A) base B) inferior border C) apex D) diaphragmatic surface E) left border

apex

The left ventricle pumps blood into the systemic circuit through the ________. A) left atrioventricular (mitral) valve B) pulmonary veins C) pulmonary trunk D) ascending aorta E) venae cavae

ascending aorta

When not filled with blood the anterior portion of each atrium deflates and becomes a rather lumpy and wrinkled flap called the________. A) atrial sinus B) coronary sulcus C) atrial apex D) interatrial groove E) auricle

auricle

The inherent ability of cardiac muscle tissue to contract in the absence of neural or hormonal stimulation is called ________. A) threshold B) systole C) diastole D) autorhythmicity E) a cardiac pacemaker

autorhythmicity

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

base

Which of the following is a major component of the cardiac conduction system located in the interventricular septum, and extends toward the apex of the heart? A) SA node B) bundle branches C) AV node D) Purkinje fibers E) internodal pathways

bundle branches

A complete heartbeat is referred to as a(n) ________. A) cardiac cycle B) arrhythmia C) diastole D) internodal pathway E) systole

cardiac cycle

The extensive connective tissue network, which encircles the bases of the pulmonary trunk and aorta and the valves of the heart, is called the ________ of the heart. A) cardiac skeleton B) endocardium C) intercalated network D) pericardium E) pulmonary epicardium

cardiac skeleton

The superior end of the right ventricle, which tapers to a smooth-walled pouch and ends at the pulmonary valve is called (the) ________. A) auricle B) conus arteriosus C) aortic sinus D) ligamentum arteriosum E) fossa ovalis

conus arteriosus

Which of the following structures is a large, thin-walled vein that lies in the posterior portion of the coronary sulcus? A) posterior veins of left ventricle B) middle veins of left ventricle C) aortic sinus D) great cardiac vein E) coronary sinus

coronary sinus

Which surface feature marks the border between the atria and the ventricles? A) coronary sulcus B) interatrial groove C) posterior interventricular sulcus D) anterior interventricular sulcus E) auricle

coronary sulcus

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

diaphragmatic surface

During one cardiac cycle, the ventricles spend most of their time in ________. A) systole B) contraction C) fibrillation D) diastole E) depolarization

diastole

The sinoatrial node, or cardiac pacemaker, is ________. A) electrically active nodal tissue located in the wall of the left ventricle B) embedded in the anterior two-thirds of the interventricular septum C) able to cause the atria and ventricles to contract simultaneously D) able to cause the cardiac muscle to begin to contract at the apex E) embedded in the posterior wall of the right atrium, near the entrance of the superior vena cava

embedded in the posterior wall of the right atrium, near the entrance of the superior vena cava

Which is the layer that lines the internal surface of the heart wall? A) parietal layer of the epicardium B) endocardium C) myocardium D) fibrous pericardium E) visceral layer of the epicardium

endocardium

The intercalated disc of cardiac muscle cells possess a specialized form of communicating junction termed a(n) ________. A) desmosome B) macula adherens C) gap junction D) fascia adherens E) CAM

gap junction

Which structures are responsible for creating a direct electrical connection between cardiac muscle cells? A) gap junctions B) maculae adherens C) intercalated discs D) desmosomes E) fascia adherens

gap junctions

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

has thinner muscular walls than does the left ventricle

Which vessel delivers venous blood from the tissues and organs of the abdominal and pelvic cavities, and from the lower limbs? A) coronary veins B) pulmonary trunk C) superior vena cava D) fossa ovalis E) inferior vena cava

inferior vena cava

Structures in the heart that carry electrical signals from the SA node to the AV node are called ________. A) internodal pathways B) bundle branches C) Purkinje fibers D) chordae tendineae E) moderator bands

internodal pathways

Which of the following is a function of the cardiac skeleton of the heart? A) isolates atrial and ventricular muscle cells B) provides instructions for cardiac muscle cells to contract C) maintains the energy reserves in the form of glycogen and lipid inclusions D) provides full range mobility to the valves of the heart E) physically connects the atrial muscle cells to the ventricular muscle cells

isolates atrial and ventricular muscle cells

Which of the following is a feature that is unique to the left atrium? A) left atrioventriciular (mitral) valve B) fossa ovalis C) right atrioventricular (tricuspid) valve D) foramen ovale E) conus arteriosus

left atrioventricular (mitral) valve

Which vessel gives rise to a circumflex branch and an anterior interventricular branch? A) left marginal branch B) coronary sinus C) left coronary artery D) posterior descending artery E) right coronary artery

left coronary artery

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

left ventricle

Which of the following associations is correct? A) mitral valve-atrioventricular B) pulmonary valve-atrioventricular C) aortic valve-chordae tendineae D) tricuspid valve-semilunar valve E) pulmonary valve-chordae tendineae

mitral valve-atrioventricular

The outermost layer of the serous pericardium is termed the ________. A) parietal pericardium B) fibrous pericardium C) visceral pericardium D) endocardium E) epicardium

parietal pericardium

Which features are described as prominent muscular ridges that extend along the inner surface of the right auricle and across the adjacent anterior wall of the right atrium? A) chordae tendineae B) foramina ovale C) papillary muscles D) pectinate muscles E) trabeculae carneae

pectinate muscles

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

pressure changes

Blood leaves the right ventricle through the ________ valve to reach the capillaries supplying the lungs. A) aortic B) left atrioventricular (mitral) C) pulmonary D) right atrioventricular (tricuspid) E) bicuspid

pulmonary

Which of the following is a unique feature of the right ventricle? A) left atrioventricular (mitral) valve B) papillary muscles C) aortic valve D) pulmonary valve E) trabeculae carneae

pulmonary valve

The left atrium receives oxygen-rich blood from the ________. A) coronary arteries B) venae cavae C) pulmonary veins D) descending aorta E) pulmonary arteries

pulmonary veins

If the cusps of an atrioventricular valve are damaged or functionally impaired so that they do not close completely during the normal point in the cardiac cycle, blood may flow backwards. This is called ________. A) ischemia B) regurgitation C) thrombosis D) automaticity E) nodal depolarization

regurgitation

Oxygen-poor blood travels from the right atrium into the right ventricle through the ________ valve. A) bicuspid B) aortic C) left atrioventricular (mitral) D) right atrioventricular (tricuspid) E) pulmonary

right atrioventricular (tricuspid)

The right border of the heart is supplied by the ________. A) circumflex artery B) posterior interventricular artery C) anterior interventricular artery D) right marginal artery E) great cardiac vein

right marginal artery

Which branch(es) of the right coronary artery extends toward the apex along the anterior surface of the right ventricle of the heart? A) circumflex branch B) posterior interventricular branch C) atrial branches D) right marginal branch E) anterior interventricular branch

right marginal branch

Which structure makes up a large percentage of the anterior (sternocostal) surface of the heart? A) right atrium B) left atrium C) right ventricle D) left ventricle E) pulmonary trunk

right ventricle

The moderator band is located in the ________ and connects to the ________. A) left ventricle; anterior papillary muscle B) right atrium; pectinate muscles C) right ventricle; anterior papillary muscle D) left atrium; pectinate muscle E) interatrial sulcus; cardiac skeleton

right ventricle; anterior papillary muscle

Which coronary vein receives blood from the posterior surfaces of the right atrium and ventricle? A) small cardiac vein B) middle cardiac vein C) coronary sinus D) anterior cardiac vein E) posterior vein of left ventricle

small cardiac vein

The ________ of the heart includes the bases of the major vessels. A) right border B) inferior border C) left border D) superior border E) diaphragmatic surface

superior border

Because cardiac muscles are mechanically, chemically, and electrically connected to one another, cardiac muscle tissue functions like a single enormous muscle cell. For this reason, it is called a functional ________. A) sulcus B) inclusion C) syncytium D) intercalation E) triad

syncytium

During ventricular diastole ________. A) only the AV valves open B) only the AV valves close C) only the semilunar valves close D) the semilunar valves close and the AV valves open E) the semilunar valves open and the AV valves close

the semilunar valves close and the AV valves open

The ________ are a series of irregular muscular folds formed on the internal surface of the ventricles. A) trabeculae carneae B) papillary muscles C) chordae tendineae D) moderator bands E) pectinate muscles

trabecular carneae

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

ventricles are filling