chapter 21

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

80-100 beats per minute

________ 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. Serotonin Cholecystokinin Acetylcholine (ACh) Norepinephrine (NE) Dopamine

Acetylcholine (ACh)

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

All of the answers are correct

Which event typically occurs at the start of a cardiac cycle? Ventricular blood pressure drops until reverse blood flow pushes the cusps of the semilunar valves together. The semilunar valves open and blood is ejected. Ventricular contraction pushes the atrioventricular valves closed. Atrial contraction forces a small amount of blood into the relaxed ventricles. 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? Chordae tendineae are loose. The volume of the ventricles changes dramatically. Blood exits from the ventricles. Atrioventricular valves are closed. Semilunar valves are open .

Atrioventricular valves are closed.

________ is the term used to indicate a heart rate that is slower than normal. Angina Coronary ischemia Bradycardia Cardiac tamponade Tachycardia

Bradycardia

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

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

Each cardiac contraction follows a precise sequence. At time=0, atrial activation begins when the AV node depolarizes. True False

False

In the cardiac cycle, as atrial systole ends, ventricular diastole begins and continues until the start of the next cardiac cycle. True False

False

Since the heart is rotated slightly to the left, the anterior surface, consists primarily of both atria. True False

False

The fibrous pericardium lies deep to the serous pericardium. True False

False

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

SA node

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

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

Arteries transport blood away from the heart True False

True

Each atrioventricular valve consists of the following: a ring of connective tissue that attaches to the fibrous skeleton of the heart; connective tissue cusps, which function to close the opening between the heart chambers; and chordae tendineae that attach the margins of the cusps to the papillary muscles of the heart wall. True False

True

Norepinephrine release produces an increase in both the heart rate and force of contraction through the stimulation of beta receptors on nodal cells and contractile cells. True False

True

The cardiac skeleton reinforces the valves and helps prevent overexpansion of the heart. True False

True

The epicardium is another name for the visceral pericardium. True False

True

The heart rate may be influenced or modified by the autonomic nervous system. True False

True

The major branches of the right coronary artery are the atrial branches, which supply the right atrium and a portion of the left atrium; the posterior interventricular branches, which supply the interventricular septum and adjacent portions of the ventricles; and the branches to the conducting system, which supply the SA node and the AV node. True False

True

The myocardium consists of multiple, interlocking layers of cardiac muscle tissue, with associated connective tissue, blood vessels, and nerves. True False

True

When the left ventricle contracts, the distance between the base and apex decreases, and the diameter of the ventricular chamber decreases. True False

True

The pericardial cavity is actually ________. contains 150+ mL of pericardial fluid a large space a potential space filled with mucin 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, b, c a, d, e a, b, c, e a, c, e a, b, d

a, b, c

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. b, c, d, e a, b, e a, c, d, e a, b, c, d, e a, d, e

a, d, e

Which of the following associations is correct? sympathetic nervous system − vagus nerves acetylcholine − muscarinic receptors on nodal cells and contractile cells norepinephrine − alpha receptors on nodal cells and contractile cells baroreceptors − sensitivity to dissolved gas concentration sparasympathetic nervous system − cardiac nerves

acetylcholine − muscarinic receptors on nodal cells and contractile cells

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

activation of the sympathetic nervous system

Cardiac muscle cells obtain energy almost exclusively through ________. aerobic respiration the Krebs cycle glycolysis protein reserves anaerobic pathways

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 ________. anastomoses autorhythmicity prolapse intercalation syncytium

anastomoses

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

anterior cardiac veins

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

aortic

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

apex

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

ascending aorta

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

auricle

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

autorhythmicity

The broad, superior portion of the heart is the ________. sternocostal surface base anterior surface pulmonary surface apex

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? bundle branches SA node internodal pathways Purkinje fibers AV node

bundle branches

The exchange of oxygen and carbon dioxide in the cardiovascular system occurs in which vessels? arteries venules veins arterioles capillaries

capillaries

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

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. intercalated network pulmonary epicardium cardiac skeleton pericardium endocardium

cardiac skeleton

Which element of the fibrous pericardium stabilizes the position of the heart and associated vessels within the mediastinum? elastic fibers reticular fibers collagen fibers cartilage skeletal muscle

collagen fibers

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

conus arteriosus

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

coronary sinus

Which surface feature marks the border between the atria and the ventricles? auricle interatrial groove coronary sulcus anterior interventricular sulcus posterior interventricular sulcus

coronary sulcus

Externally, the posterior and inferior portions of the left and right ventricles form the ________. sternocostal surface left border superior border right border diaphragmatic surface

diaphragmatic surface

During one cardiac cycle, the ventricles spend most of their time in ________. diastole fibrillation depolarization systole contraction

diastole

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

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? fibrous pericardium parietal layer of the epicardium endocardium visceral layer of the epicardium myocardium

endocardium

The visceral pericardium is also called the ________. endocardium parietal pericardium fibrous pericardium myocardium epicardium

epicardium

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

gap junction

Which structures are responsible for creating a direct electrical connection between cardiac muscle cells? maculae adherens intercalated discs fascia adherens desmosomes gap junctions

gap junctions

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

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? fossa ovalis pulmonary trunk superior vena cava inferior vena cava coronary veins

inferior vena cava

Cardiac muscle cells differ from skeletal muscle fibers in that the cardiac muscle cells are uniquely interconnected by (the) ________. Z discs gap junctions Intercalated discs sarcoplasmic reticulum T tubules

intercalated discs

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

internodal pathways

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

isolates atrial and ventricular muscle cells

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

left atrioventriciular (mitral) valve

Which vessel gives rise to a circumflex branch and an anterior interventricular branch? posterior descending artery coronary sinus right coronary artery left marginal branch left coronary artery

left coronary artery

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

left ventricle

The primary function of the pericardial fluid is to provide ________ between the pericardial membranes. friction pressure lubrication impulse stimulation perforation

lubrication

Which of the following associations is correct? tricuspid valve − semilunar valve aortic valve − chordae tendineae pulmonary valve − chordae tendine aemitral valve − atrioventricular pulmonary valve − atrioventricular

mitral valve − atrioventricular

The outermost layer of the serous pericardium is termed the ________. visceral pericardium fibrous pericardium endocardium epicardium parietal pericardium

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? trabeculae carneae chordae tendineae pectinate muscles foramina ovale papillary muscles

pectinate muscles

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

pressure changes

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

pulmonary

The ________ carries blood to and from the gas exchange surfaces of the lungs. infundibular circuit hepatic portal circuit pulmonary circuit systemic circuit arterial circle of Willis

pulmonary circuit

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

pulmonary valve

The left atrium receives oxygen-rich blood from the ________. venae cavae coronary arteries pulmonary veins pulmonary arteries descending aorta

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 ________. nodal depolarization regurgitation ischemia thrombosis automaticity

regurgitation

Oxygen-poor blood travels from the right atrium into the right ventricle through the ________ valve. aortic right atrioventricular (tricuspid) pulmonar bicuspid left atrioventricular (mitral)

right atrioventricular (tricuspid)

Which heart structure receives blood from the systemic circuit? left ventricle right ventricle left atrium right atrium pulmonary veins

right atrium

The right border of the heart is supplied by the ________. right marginal artery great cardiac vein anterior interventricular artery posterior interventricular artery circumflex artery

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? right marginal branch anterior interventricular branch posterior interventricular branch atrial branches circumflex branch

right marginal branch

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

right ventricle

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

right ventricle; anterior papillary muscle

Which coronary vein receives blood from the posterior surfaces of the right atrium and ventricle? anterior cardiac vein posterior vein of left ventricle small cardiac vein middle cardiac vein coronary sinus

small cardiac vein

The ________ of the heart includes the bases of the major vessels. left border right border inferior border diaphragmatic surface superior border

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 ________. inclusion syncytium triad intercalation sulcus

syncytium

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

systemic circuit

During ventricular diastole ________. the semilunar valves close and the AV valves open the semilunar valves open and the AV valves close only the AV valves open only the semilunar valves close only 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. papillary muscles trabeculae carneae moderator bands pectinate muscles chordae tendineae

trabeculae carneae

During the late stages of ventricular diastole, the ________. atria are contracting ventricles are filling pressure in the ventricles does not change AV valves are closed ventricles are contracting

ventricles are filling