The Heart Flashcards
The area between the two pleural cavities is the:
mediastinum
The broad posterior part of the heart is the:
base
The apex is the
inferior left corner
The top of the heart is at the level of the:
second costal cartilage
The fibrous pericardium is composed of:
dense connective tissue
Which layer of pericardium is on the surface of the heart?
visceral
The pericardial cavity is between the __ layers.
parietal and visceral
Severe pericarditis can cause:
cardiac tamponade
Another name for the visceral layer is the:
epicardium
Which layer is composed of endothelium?
endocardium
Which layer is composed of cardiac muscle?
myocardium
Has pectinate muscles
atria
Has thin walls
atria
Has trabeculae carneae
ventricles
Pumping chambers
ventricles
Has thick walls
ventricles
Receiving chambers
atria
The chamber that forms most of the anterior surface.
Right ventricle
The chamber on the posterior side of the heart.
Left atrium
The chamber with the thickest walls.
Left ventricle
The chamber that forms the entire right border of the heart.
Right atrium
Involved in pulmonary circulation.
Right atrium, Right ventricle
Involved in systemic circulation.
Left atrium, Left ventricle
Receives blood from the SVC, IVC and coronary sinus.
Right atrium
Receives blood from the pulmonary veins.
Left atrium
Receives blood from the left atrium.
Left ventricle
Receives blood from the right atrium.
Right ventricle
Strings attached to the AV valve cusps
Chordae tendineae
Wall between the two atria
Interatrial septum
Wall between the two ventricles
Interventricular septum
“Little ear” at medial corner of atria
Auricle
Groove between the atria and ventricles
Coronary sulcus
Muscular ridges in the atria
Pectinate muscles
Muscular ridges in the ventricles
Trabeculae carneae
Bumps of muscle attached to strings
Papillary muscles
Depression in the interatrial septum
Fossa ovalis
Pathway of Blood through the Heart
Superior vena cava, Right atrium, Tricuspid valve, Right ventricle, Pulmonary semilunar valve, Pulmonary trunk, Pulmonary artery, R. lung (arterioles, capillaries, venules), Pulmonary vein, Left atrium, Bicuspid (mitral) valve, Left ventricle, Aortic semilunar valve, Ascending aorta
The part of a heartbeat when the chambers contract is called:
systole
The part of a heartbeat when the chambers relax is called:
diastole
Which chambers contract first?
atria
Chordae tendineae attach to:
atrioventricular valves
The valve between the left atrium and left ventricle is the:
bicuspid
The valve between the right atrium and right ventricle is the:
tricuspid
Valves with pouch-like cusps are the:
semilunar valves
Which valves close when atrial pressure is less than ventricular pressure?
AV
Which valves close when ventricular pressure is less than arterial pressure?
semilunar
Semilunar valves are named for:
the vessel they are in.
Valves function to:
prevent backwards flow of blood
Closing of the semilunar valves causes the:
second heart sound (dup)
Closing of the AV valves causes the:
first heart sound (lub)
The fibrous skeleton surrounds and strengthens the:
heart valves
Intrinsic Conduction System
Sinoatrial node; pacemaker (right atrium near SVC), Atrioventricular node ( interatrial septum above tricuspid valve), Atrioventricular bundle (bottom of interatrial septum), Right and left bundle branches (sides of interventricular septum), Purkinje fibers (throughout myocardia of ventricles).
Which structure provides the only conduction pathway between the atria and ventricles?
AV bundle
Damage to the AV node or AV bundle, as in a heart block, causes:
the ventricles to beat too slowly
Under the microscope, cells of the nodes and AV bundle look like:
small cardiac muscle cells
Where are Purkinji fibers located?
between the endocardium and myocardium
Slows heart rate
parasympathetic
Increases heart rate and force of contractions
sympathetic
Fibers are branches of the vagus nerve
parasympathetic
Fibers come from the cervical and upper thoracic chain ganglia
sympathetic
Innervates SA node, AV node, coronary arteries and cardiac musculature throughout heart
sympathetic
Innervates only the SA node, AV node, and coronary arteries
parasympathetic
Influenced by the cardioinhibitory center of the medulla
parasympathetic
Influenced by the cardioacceleratory center of the medulla
sympathetic
The first vessels to branch off the aorta are the:
coronary arteries
What artery supplies the right atrium?
right coronary
The two branches of the left coronary artery are the:
anterior interventricular and circumflex
What artery supplies the medial portion of the right and left ventricles?
anterior interventricular
What artery supplies the left atrium and posterior part of the left ventricle?
circumflex
Which vessel receives blood from the great, middle and small cardiac veins?
coronary sinus
The coronary sinus empties its blood into the:
right atrium
An accumulation of fatty deposits in the arteries supplying the heart wall
Coronary artery disease
Thoracic pain caused by inadequate oxygenation of heart muscle cells
Angina pectoris
Death of cardiac muscle cells, often caused by blockage of a coronary artery
Myocardial infarction
Condition in which the heart enlarges greatly while its pumping efficiency progressively declines; cause unknown, but may involve a feedback loop of sympathetic stimulation
Congestive heart failure
Enlargement or failure of the right ventricle due to elevated pressure in the pulmonary circuit
Cor pulmonale
An arrhythmia in which the ventricles undergo rapid, random firing of electrical impulses within ventricular cardiac muscle
Ventricular fibrillation
An arrhythemia in which multiple waves of impulses circle within the atrial myocardium, randomly stimulating the AV node
Atrial fibrillation
Inflammation of the inner lining of the heart, usually confined to the heart valves; may be bacterial, fungal or autoimmune.
Endocarditis
a) Explain why the pulmonary arteries are blue and the pulmonary veins are red on charts and models. What does the color indicate about the blood each of these vessels carries?
b) Explain why the pulmonary arteries are arteries even though they are blue and the pulmonary veins are veins even though they are red. What is this telling us about the direction of blood flow?
a) Pulmonary arteries are blue because they carry deoxygenated blood that has just returned from the systemic circulation to the lungs where it will pick up oxygen. The pulmonary veins are red because the blood they carry is rich in oxygen.
b) Pulmonary arteries are arteries because they carry blood away from the heart, which is the definition of an artery. Pulmonary veins, like all other veins, carry blood back towards the heart from a capillary bed.
Both pulmonary arterial hypertension (p. 580) and the congenital heart defect that occurs in tetralogy of Fallot (p. 583) lead to enlargement of the right ventricle. Explain what these two conditions have in common and why this causes the right ventricle to enlarge.
In both these conditions the right ventricle is working against a higher than normal pressure to push blood into the lungs, either because of high pulmonary pressure or because of stenosis (narrowing) of the entry to the pulmonary trunk. Because the right ventricle is working harder, the myocardium enlarges to try to overcome the increased resistance it is working against (like any other muscle that must work harder). Unfortunately, overtime the myocardium of the right ventricle becomes exhausted and eventually fails.
A myocardial infarction will sometimes cause damage to the SA node. Assuming this is the only part of the intrinsic conduction system that is damaged, a) what structure will be the new pacemaker of the heart, and b) would you expect the patient’s resting heart rate to be faster, slower or the same as normal? Why? (p. 577-578)
a) If the SA node is damaged, the AV node will take over as the pacemaker of the heart.
b) In this cause the resting heart rate will tend to be slower because the intrinsic rate of depolarization of the AV node is slower than that of the SA node.
