Mastering A&P Chapter 19 (heart)

The terminal conducting elements in the ventricular myocardium are?

Purkinje fibers (subendocardial branches)

In what ways are Purkinje fibers (subendocardial branches) different from typical cardiac muscle cells?

They are larger in diameter and contain fewer myofilaments.

What is the effect of the parasympathetic fibers carried by the vagus nerve?

They slow the heartbeat

Destruction of which structure will result in electrical signals traveling to only one ventricle?

bundle branch

A penetrating stab wound to the heart wall that causes blood to leak into the pericardial cavity would result in

cardiac tamponade

The accumulation of pericardial fluid due to inflammation or the accumulation of blood in the pericardial cavity can lead to

cardiac tamponade

the fibrous skeleton of the heart functions in all of these ways EXCEPT in __________.

causing direct spread of electrical impulses from the atria to the ventricles

Threadlike structures of the endocardium that prevent prolapse of the atrioventricular valves.

chordae tendinae

the heart strings are

chordae tendinae

The two semilunar valves __________.

close when ventricles relax

Which vessel returns most of the venous blood from the heart to the right atrium?

coronary sinus

the auricles are

earlike flaps on the surface of the atria.

Which statement concerning the pulmonary arteries is FALSE?

The pulmonary arteries carry poorly oxygenated blood. The right ventricle pumps blood into the pulmonary arteries. The pulmonary arteries are part of the pulmonary circuit. The pulmonary arteries carry oxygenated blood back from the lungs to the heart.

Name the inner lining of the heart

endocardium

The cusps of the valves of the heart are covered by

endocardium

The inner endothelial layer that lines the heart is the

endocardium

Which layer of the heart wall is visceral pericardium?

epicardium

Contraction of the heart proceeds first on the right side of the heart and second on the left.

false

Oxygenated blood flows through the right side of the heart.

false

Papillary muscles are horizontal ridges in the walls of the atrium.

false

The base of the heart is located at the bottom of the heart.

false

The correct sequence of heart wall layers from superficial to deep is epicardium, endocardium, and myocardium.

false

The first branch off the arch of the aorta is the brachiocephalic artery in both the sheep and the human.

false

The desmosome-like structures that attach adjacent cardiac muscle cells are called

fasciae adherens

During ventricular systole, blood is

forced from the ventricles into the aorta and pulmonary trunk.

Which surface of the heart is dominated by the left ventricle?

inferior

The atrioventricular node is located in the

inferior part of the interatrial septum.

hich feature is unique to cardiac muscle tissue relative to other types of muscle tissue?

intercalated discs

Serous fluid in the pericardial cavity __________.

is secreted by the epithelial cells of both layers of the serous pericardium

Blood within the pulmonary veins returns to the

left atrium

The heart chamber that receives oxygenated blood from the pulmonary veins.

left atrium

The heart chamber that pumps oxygenated blood around the systemic circuit is the

left ventricle

The heart chamber with the thickest wall is the

left ventricle

The most muscular chamber of the heart

left ventricle

What heart chamber pushes blood through the aortic semilunar valve?

left ventricle

In the pericardial sac, the ________ lies directly deep to the fibrous pericardium.

parietal layer of the serous pericardium

Name the ridged bundles of muscle found projecting inside the right atrium.

pectinate muscles

Which heart chamber has the thickest myocardium?

the left ventricle, because it pumps blood at a higher pressure

The pericardial cavity lies between

the parietal pericardium and the visceral pericardium.

Which of the following structures is not found in the left ventricle?

the pectinate muscles

The right ventricle pumps blood into which vessel?

the pulmonary trunk

The semilunar valves prevent backflow of blood into the _____.

ventricles

rregular ridges of muscle called trabeculae carneae are located within the walls of the__________

ventricles

The semilunar valves are closed when

ventricles are relaxing

During which stage of the heartbeat is the valve shown here closed?

ventricular contraction (ventricular systole)

In common usage, the terms "systole" and "diastole" refer to __________, respectively.

ventricular contraction and ventricular filling

Select the correct partial path below. This path is part of the complete blood flow pathway. You should be able to trace flow starting in any location.

Aorta to smaller systemic arteries to systemic capillaries to systemic veins to right atrium through the tricuspid valve

Which of these statements concerning cardiac muscle tissue is true?

Cardiac muscle tissue exhibits inherent rhythmicity, which is the basis of coordinated heartbeats.

What fibrous structure functions to anchor the atrioventricular valves in a closed position?

Chordae Tendinae

Pericarditis is inflammation of the pericardial lining of the heart, the serous pericardium. One of the conditions associated with pericarditis is called cardiac tamponade. Which of the following statements correctly describes cardiac tamponade?

Excess fluid in the pericardial cavity compresses the heart. Cardiac tamponade can be alleviated by inserting a needle into the pericardial cavity and withdrawing excess fluid. Cardiac tamponade is associated with increased fluid buildup in the pericardial cavity resulting from the inflammatory response.

The moderator band is found on both the right and left side of the heart.

False

Defects of heart valves are common and result from a number of causes. Which of the following statements about valve disorders is correct?

Mitral and aortic valves are most often involved in valve disorders because they are subjected to the greatest pressure associated with left ventricular contraction.

What is the function of the coronary circulation

Provide a blood supply to the heart

Which areas of the heart are innervated by parasympathetic nerve fibers?

SA and AV Nodes

Which of these conduction sequences through the heart is correct?

SA node, AV node, AV bundle, bundle branches, Purkinje fibers

Why is the only path of conduction for impulse transmission from the atria to the ventricles through the AV node and AV bundle?

The atria and ventricles are insulated from each other by the fibrous skeleton of the heart.

A physician determines that the apex of a patient's heart lies at the costal cartilage of the fourth rib two fingers' breadth to the right of the sternum. What can the physician immediately determine about the patient's heart?

The heart is displaced superiorly and to the right

Name the irregular ridges of muscle lining the ventricles.

Trabecular carneae

Blood on the right never mixes with blood on the left, once the heart is fully developed.

True

Parasympathetic impulses to the SA node are transmitted on this cranial nerve.

Vagus Nerve

Pericarditis can lead to all of the following except

a myocardial infarction.

The parietal layer of the serous pericardium __________.

adheres to the inner surface of the fibrous pericardium

During left ventricular systole, blood exits the heart to enter the

aorta

When the ventricles relax, intraventricular pressure falls and __________.

blood is pushed against the semilunar valves, causing them to close

A medical student is listening to a specific valve of a patient's heart in the region of the second intercostal space and the right sternal margin. The student is listening to the __________ valve.

aortic

Blood moves from the left ventricle into what vessel?

ascending aorta

Cells of the conducting system located between the AV node and bundle branches.

atrioventricular bundle

Identify the ear like flaps that are attached to the top chambers of the heart.

auricle

Semilunar valves are located

between the ventricles and the great arteries.

Valve found between the left atrium and left ventricle

bicuspid valve

Purkinje fibers (subendocardial branches) are __________.

long rows of special large-diameter, cardiac cells with few myofilaments that are specialized for conduction

The region between the right and left pleural cavities is the

mediastinum.

The cardiac centers that control heart rate are located in the

medulla oblongata of the brain stem.

Heart valve with two cusps.

mitral valve

Of the three layers of the heart wall, the layer that contains the cardiac muscle is the

myocardium

Which structure anchors the chordae tendinae of the atrioventricular valves?

papillary muscle

Contraction of these structures tightens the chordae tendineae, preventing valve prolapse.

papillary muscles

What structures anchor the chordae tendineae?

papillary muscles

What is the function of the chordae tendineae and papillary muscles of the bicuspid and tricuspid valves?

preventing eversion of the valves into the atria

Stenosis of the mitral valve may cause blood to back up into the

pulmonary circulation

The valve responsible for preventing backflow of blood from the lungs into the heart.

pulmonary semilunar valve

dentfiy the valve located at the exit of the right ventricle.

pulmonary semilunar valve

Most anterior of the heart

pulmonary trunk

Which of the following vessels does not carry oxygen-poor blood to the heart?

pulmonary vein

Which vessel carries oxygenated blood?

pulmonary vein

The left ventricular wall of the heart is thicker than the right ventricular wall so that it can

pump blood with greater pressure

ligamentum arteriosum

remnant of ductus arteriosus

Oxygen-poor blood returns to the heart and enters the

right atrium

The heart chamber that receives blood from the superior vena cava, inferior vena cava, and coronary sinus.

right atrium

Which chamber of the heart exits into the pulmonary trunk?

right ventricle

Large cardiac cells of the conducting system embedded in the ventricular walls between the endocardium and myocardium.

subendocardial conducting network (Purkinje fibers)

Which vessels drain into the right atrium?

superior and inferior vena cava and the coronary sinus

At which corner point of the heart does one listen for the sound of the closing aortic semilunar valve?

superior right

A drop of blood returning to the heart from the head region would enter the heart through which vessel?

superior vena cava

Branches of the vagus nerve __________.

supply parasympathetic innervation to the heart, which slows the heart rate

Identify the right atrioventricular valve.

tricuspid valve

Oxygen-rich blood returning from the lungs enters the left atrium through two right and two left pulmonary veins.

true

Prolapse of the atrioventricular valves is prevented by the chordae tendineae.

true

The epicardium is the same as the

visceral layer of serous pericardium.

The tricuspid valve is closed

when the ventricle is in systole