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