A&P 2: Chapter 19 (Cardiovascular System: Heart)

The shutting of the semilunar valves occurs during which phase?

atrial relaxion/ventricular filling??!

Which action leads to the closure of the right atrioventricular valve?

contraction of the ventricles

At the AV node of the conduction system, the action potential is ----?

delayed due to the cells being small and having few gap junctions.

During ventricular contraction: 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.

e

The heart valves - ?

ensure that blood flow is "one-way"

Which layer (of the pericardium) is made of dense irregular connective tissue?

fibrous pericardium

The atrioventricular (AV) node is located in the -?

floor of the right atrium

The left and right coronary arteries are _________ ____ ________, because the blockage of one of them leads to tissue death in the area it supplies.

functional end arteries

Cardiac output equals the

heart rate multiplied by stroke volume

What are the cell-to-cell contacts of the cardiac muscle fibers called?

intercalated discs

Pectinate muscles are found on the ?

internal walls of the right and left atria

The layer of the heart wall composed of cardiac muscle tissue is the ?

myocardium

Coronary vessels are open when the heart is ?

relaxed

The internal wall surface of each ventricle displays large, smooth, irregular muscular ridges called ?

trabeculae carneae

what are the three main factors influencing stroke volume?

venous return, inotropic agents, afterload

According to the Frank-Starling law, as the volume of blood entering the heart increases, ____________ ____________ become more forceful

ventricular contractions

True/False: Cardiac reserve is greater in a nonathletic individual than in a highly trained athlete.

False

True/False: The hearts nodal cells have a more negative resting potential than neurons do, because nodal cells lack leak channels for sodium and potassium ions.

False

True/False: Arteries carry blood toward the heart, while veins carry blood away from the heart.

False

True/False: Blood flow to the heart wall courses through coronary vessels in a steady stream.

False

True/False: Immediately prior to atrial contraction, blood continues to enter the atria from the venae cavae and pulmonary veins.

True

True/False: Like skeletal muscle cells, cardiac muscle cells have an absolute refractory period prior to repolarization.

True

True/False: Myofibrils within cardiac muscle cells are aligned in sarcomeres.

True

True/False: Nodal cells contain fast voltage-gated calcium channels.

True

True/False: The main functions of the cardiovascular system include the transport and exchange of respiratory gases, nutrients, and wastes throughout the body.

True

True/False: The pericardium helps prevent overfilling of the heart and it lessens the friction of movements during heartbeats.

True

True/False: The receiving chambers of the heart are the atria, and the forcefully pumping chambers of the heart are the ventricles.

True

Vagal tone refers to the -? a: decreasing of the heart rate below its inherent rhythm by parasympathetic stimulation. b: decreasing of the heart rate below its inherent rhythm by sympathetic stimulation. c: increasing of the heart rate above its inherent rhythm by sympathetic stimulation. d: increasing of the heart rate above its inherent rhythm by parasympathetic stimulation.

a

Which correctly describes the heart's apex? a: Projects slightly anteroinferiorly toward the left side of the body b: Projects slightly anteroinferiorly toward the right side of the body c: Projects slightly posteroinferiorly toward the left side of the body d: Projects slightly posteroinferiorly toward the right side of the body e: Projects slightly posteroinferiorly toward the midline of the body

a

The pulmonary trunk receives blood from the right ventricle and conducts it toward the lung. The pulmonary trunk is a(n) _____________

artery

The plateau phase of an action potential -? a: occurs only in skeletal muscle and makes those fibers' contractions most forceful. b: leads to tetanic contractions in smooth and skeletal muscle. c: allows cardiac muscle cells to contract and then relax without locking up. d: allows cardiac muscle cells to exhibit synchronous fibrillation.

c

The atria are separated from the ventricles externally by the ?

coronary sulcus

Which segment of the ECG reflects the plateau phase of ventricular muscle cells' action potentials?

S-T segment

Which carries oxygenated blood from the lungs to the heart?

pulmonary veins

Sympathetic innervation of the heart arises from the ________ segments of the spinal cord.

T1-T5

To initiate a cardiac muscle cell contraction, calcium binds to ______?

troponin

Which 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 carry blood away from the heart. e: Veins carry blood toward the heart.

a,d,e

Cardiac output is usually expressed in

liters per minute

The units for perfusion of blood are typically __________.

mL/min/gram

The pericardial cavity is between the ?

parietal and visceral layers of the serous pericardium

The term "epicardium" is another name for the

visceral layer of serous pericardium

True/False: Cardiac muscle is able to use a variety of fuel types for cellular respiration.

True

True/False: Parasympathetic innervation influences the heart rate, but generally tends to have no direct effect on the force of contractions.

True

True/False: Preload is the stretch of the heart wall as determined by the amount of blood returned by the veins.

True

True/False: SA nodal cells are autorhythmic.

True

An autorhythmic heart cell is one in which _?_ a: action potentials fire spontaneoulsy. b: action potentials are stimulated by internal stores of acetylcholine. c: action potentials always occur at exactly the same frequency. d: all filaments contract and relax with a high degree of synchrony. e: action potentials are initiated by the autonomic nervous system.

a

As blood is pumped out of the heart and into the major arteries leaving the heart, it a: pushes against the semilunar valves and opens them. b: pushes against the semilunar valves and closes them. c: fills the cusps of the semilunar valves, causing them to expand and block the backflow of blood d: pushes against the atrioventricular valves and opens them. d: fills the cusps of the atrioventricular valve causing opening of the bicuspid and closure of the tricuspid.

a

During the S-T segment, what is occurring within cardiac muscle cells? a: Sodium is rapidly diffusing out of atrial muscle cells. b: Sodium channels are beginning to open in ventricular cells and calcium is entering through slow channels in atrial cells. c: Calcium is entering and potassium is leaving ventricular cells. d: Potassium is entering atrial cells and sodium is leaving ventricular cells.

c

Most of the calcium that triggers contraction of cardiac muscle comes -? a: into the cell through leakage channels in the sarcolemma. b: into the cell through voltage-gated channels in the sarcolemma. c: from the sarcoplasmic reticulum of the cell. d: from the Golgi apparatus of the cell.

c

The posterior interventricular sulcus a: is another name for the coronary sulcus. b: contains the great cardiac vein and coronary sinus. c: is a groove between the ventricles on the back of the heart. d: is a valve in the interventricular septum that closes at birth.

c

Which type of muscle cell exhibits a longer refractory period?

cardiac muscle

The papillary muscles attach to the cusps of the atrioventricular valves by means of the ?

chordae tendineae

For the repolarization phase of an SA nodal cell action potential, a: sodium and potassium channels open. b: calcium channels open and sodium channels close. c: calcium and potassium channels close. d: calcium channels close and potassium channels open. e: sodium and chloride channels open.

d

Which feature permits the compression necessary to pump large volumes of blood out of the ventricles? b: a: Negative pressure inside the ventricles c: Absence of oxygenated blood in the atria d: Arrangement of cardiac muscle in the heart wall e: Presence of skeletal muscle tissue in the heart skeleton f: Presence of papillary muscles in the ventricles

d

In an ECG, what does the T wave represent?

repolarization of the ventricles

The fossa ovalis appears just above the opening of the coronary sinus within the __________.

right atrium

Which heart chambers contain deoxygenated blood?

right atrium and right ventricle

Which pair is located more anteriorly in a heart in normal position?

right atrium, right ventricle

Each of the receiving chambers of the heart has a wrinkled flaplike extension; the one that is more visible from an anterior view is the ?

right auricle

The posterior interventricular artery is a branch off of the ?

right coronary artery

Someone with tachyarrhythmia would be expected to show an abnormally -?

small Q-T interval

Which circuit of the cardiovascular system includes the left ventricle and aorta?

systemic circuit

Which circuit of the cardiovascular system is responsible for sending blood to the kidneys, stomach, and pelvic regions?

systemic circuit

Typically, there are __________ papillary muscles that project from the wall of the left ventricle and attach to the tendinous cords that support the left AV valve.

2

How many half-moon shaped, pocketlike cusps are found in each semilunar valve?

3?

The metabolic pathways of cardiac muscle make it a: somewhat susceptible to heart attack, because it relies so exclusively on aerobic metabolism. b: extremely susceptible to heart attack, because it uses such a variety of fuel sources. c: somewhat susceptible to heart attack, because it has so few mitochondria. d: relatively resistant to heart attack, because it uses exclusively anaerobic metabolism. e: relatively resistant to heart attack, because it has a great capacity to accrue oxygen debt.

a

The right border of the heart is supplied by the ?

right marginal artery

During the plateau phase of a cardiac muscle cell's action potential, the membrane stays - ? a: depolarized as potassium exits and calcium enters. b: depolarized as potassium enters and calcium exits. c: repolarized as sodium enters and calcium exits. d: hyperpolarized as sodium and calcium exit. e: hyperpolarized as potassium enters and calcium exits.

a

Which valve prevents the backflow of blood into the left ventricle when the ventricles relax?

aortic semilunar valve

Someone with a heart block would have - ?

a prolonged P-R interval

Norepinephrine is considered a positive chronotropic agent because it causes an ________________ of the firing rate of ____________.

increase, SA nodal cells

The membrane of a contractile cardiac muscle cell contains - ? a: no calcium pumps. b: calcium pumps that move calcium out of the cell. c: calcium pumps that move calcium into the cell. d: calcium pumps that open and allow calcium to diffuse down its concentration gradient to reach equilibrium.

b

Cardiac output is the amount of blood that is pumped

by a single ventricle in one minute

In an EKG, the P wave is generated when the -?

atria depolarize

Which of the following would cause a decrease in cardiac output? a: An increase in venous return b: An increase in afterload c: Addition of positive inotropic agents d: An increase in heart rate

b

Atrial contraction occurs just before: a: isovolumetric relaxation. b: atrial relaxation and ventricular filling. c: ventricular ejection. d: isovolumetric contraction.

d

Large doses of certain stimulants can lead to dangerous increases in heart rates. Such a stimulant is a ?

positive chronotropic agent

From which view is the connection between the pulmonary veins and the heart most visible?

posterior

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 adipose connective tissue f: Has patches of myocardium

a,b,c

Metabolically, cardiac muscle relies on __________metabolism using many ___________ and a rich supply of _________.

aerobic, mitochondria, myoglobin

What would you expect a cardiologist to recommend if there was substantial occlusion to a patient's left coronary artery but not the right coronary artery? a: Because there are multiple alternate paths for blood delivery, the cardiologist would not intervene. b: Because this is a relatively small, unimportant artery, the cardiologist would not intervene. c: Because this is an important artery, and alternate vascular paths are inadequate, the cardiologist would treat the condition. d: Because occlusions require blood to be moved under greater pressure, the cardiologist would prescribe drugs to raise blood pressure.

c

What is the sequence of events in the transmission of an impulse through the heart muscle? a: AV node b: AV bundle c: SA node d: Through the atria e: Through the ventricles f: Bundle branches g: Purkinje fibers

c, d, a, b, f, g, e

During a cardiac cycle, how many of the four chambers contract at any one time?

2

Parasympathetic innervation of the heart occurs via ?

CN X

What part of the cardiac conduction system is located in the posterior wall of the right atrium, adjacent to the entrance of the superior vena cava?

SA node

Blood moves into and then out of a heart chamber because: a: it moves along its pressure gradient, and that gradient depends on contraction and relaxation during the cardiac cycle. b: it is under constant pressure, but its movement is dictated by the control of valve openings and closures. c: the veins and arteries constrict and dilate to propel and attract blood. d: All of the choices are correct.

a

Just prior to atrial contraction, a: all four chambers are at rest and AV valves are open. b: all four chambers are at rest and AV valves are closed. c: all four chambers are contracting and all valves are open. d: both ventricles are contracting and blood is being ejected into the major arteries. d: both atria are contracting and blood is being ejected into the major arteries.

a

Which are functions performed by the fibrous skeleton of the heart? a: Separates the atria and ventricles b: Anchors the heart valves c: Provides electrical insulation between the atria and ventricles d: Provides the framework for the attachment of the myocardium e: None of these are true functions of the fibrous skeleton of the heart

a,b,c,d

Sympathetic innervation of the heart a: increases the heart rate b: decreases the heart rate c: increases the force of contractions d: decreases the force of contractions e: has no effect on contraction force

a,c

Which are differences between cardiac muscle tissue and skeletal muscle tissue? a: The sarcoplasmic reticulum in cardiac muscle is less extensive. b: The sarcoplasmic reticulum in cardiac muscle is more organized. c: Cardiac muscle has intercalated discs; skeletal muscle does not. d: Cardiac muscle has 1 or 2 nuclei per cell; skeletal muscle has multiple nuclei per cell. e: Cardiac muscle has more well-defined terminal cisternae.

a,c,d

As with action potentials in other types of cells, the repolarization of cardiac muscle cells involves the -? a: entrance of calcium through voltage-gated channels. b: exit of potassium through voltage-gated channels. c: entrance of sodium through voltage-gated channels. d: binding of ACh to ACh receptor. e: simultaneous closure of sodium channels and opening of calcium channels.

b

Cardiac reserve is a: the potential increase in stroke volume someone would show if they engaged in athletic training. b: the increase in cardiac output an individual is capable of demonstrating during vigorous exercise. c: the amount of blood left in the heart after the ventricle has contracted during cardiac cycles at rest. d: the blood that the heart uses to nourish its cardiac muscle and does not put into general circulation.

b

Once an SA nodal cell reaches threshold, the depolarization phase occurs during which ----? a: potassium comes in through fast voltage-gated channels. b: calcium comes in through fast voltage-gated channels. c: potassium moves out through fast voltage-gated channels. d: sodium moves out through slow voltage-gated channels. e: calcium moves out through slow voltage-gated channels.

b

The membrane of a contractile cardiac muscle cell contains --? a: fast voltage-gated sodium channels and fast voltage-gated calcium channels. b: fast voltage-gated sodium channels and slow voltage-gated calcium channels. c: slow voltage-gated sodium channels and slow voltage-gated calcium channels. d: slow voltage-gated sodium channels and fast voltage-gated calcium channels.

b

The opening and closing of the heart valves is caused by: a: contraction and relaxation of papillary muscles that pull on heart strings. b: pressure changes of alternating contraction and relaxation during the cardiac cycle. c: contraction of the smooth muscle in the walls of the great vessels leaving the heart. d: action potentials within the cusps of the valves.

b

Occlusion of blood vessels tends to lead to ____________.

inadequate blood supply and damage to body tissues.

The serous fluid within the pericardial cavity works to

lubricate membranes of the pericardium

A drug that decreased calcium levels in a muscle cell and thereby lowered the number of crossbridges formed during the heart's contractions would be a ?

negative inotropic agent

The base of the heart faces in the _____________ directions.

posterior and superior

Which of the cardiovascular system's circuits has deoxygenated blood in its arteries?

pulmonary circuit