Term
| septal papillary muscle (of right ventricle) |
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Definition
connects to the septal cusp of tricuspid valve.
Can be confused with: posterior papillary muscle and anterior papillary muscle.
To identify: septal papillary muscle is the most superior of the papillary muscles in the right ventricle,and it attaches to the interventricular septum
Attachments: Attaches to chordae tendonae of the septal cusp of the tricuspid valve and to the interventricular septum
contract before the ventricle itself contracts, tightening the chordae tendinea and drawing the cusps of the valve together to prevent backflow of blood into the right atrium
Innervation: Purkinje fibers from the right bundle innervate the anterior papillary muscle of the right ventricle via the septomarginal trabecula or moderator band, to coordinate the timing of the contraction of the papillary muscles
Formation: papillary muscles form inwardly from the heart wall at the same time as the muscular interventricular septum, from mesodermal tissue
Blood supply: Coronary arteries, mostly the right coronary artery but also the LAD |
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Term
| septal cusp of tricuspid valve |
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Definition
connects to the anterior and posterior cusps of the tricuspid valve and chordae tendineae attached to the septal papillary muscle
Can be confused with: posterior or anterior cusp of tricuspid valve.
To identify: septal cusp is located between the septal papillary muscle and posterior papillary muscle. If you consider the valve as a clock, it runs from approximately 1 o'clock - o'clock when viewed from the right ventricle.
Attachments: attaches to the chordae tendineae (of the septal papillary muscle) and to the anterior and posterior cusps of the tricuspid valve.
Purpose of valve: to prevent backflow of blood into the right atrium during systole, they open during
Formation: right side of the atrial canal, formed by the presence of the septum intermedium, eventually becomes the tricuspid valve, mesodermal tissue
Special: auscultation of tricuspid valve can be conducted between the 5th and 6th rib near the sternum. The "first" heart sound in the lub-dub is the closing of the tricuspid and bicuspid valves.
pathology:Tricuspid regurgitation is not uncommon in the tricuspid valve.
It is a common valve to be infected (endocarditis) in IV drug users. Patients who inject narcotics or other drugs intravenously may introduce infection, which will travel to the right side of the heart, most often caused by S. aureus. In other patients without a history of intravenous exposure, endocarditis is more frequently left-sided (bicuspid).
The tricuspid valve can be affected by rheumatic fever, which can cause tricuspid stenosis or tricuspid insufficiency (also called tricuspid regurgitation). Some patients are born with congenital abnormalities of the tricuspid valve. Congenital apical displacement of the tricuspid valve is called Ebstein's anomaly and typically causes significant tricuspid regurgitation. |
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Term
| snterior cusp, pulmonary valve |
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Definition
portion of the pulmonary valve which separates the right ventricle from the pulmonary trunk.
Can be confused with: right or left pulmonary cusps
To identify: when looking from above, first identify the pulmonary trunk (vessel coming out of right ventricle). Assume anterior side is the one furthest from the heart. This is the anterior valve. It also lines up with the posterior valve of the aorta.
Attachments: right and left pulmonary cusps
Purpose of valve:to prevent backflow of blood into the right ventricle during diastole
Special: auscultation of the pulmonary valve can be detected between the left 2nd and 3rd rib near the sternum
Systolic contraction results in the forceful ejection of blood from the ventricles into the pulmonary or systemic circulation; the AV valves are closed and the aortic and pulmonary valves are opened.
The "second" heart sound in the lub-dub is the closing of the aortic and pulmonary valves.
pathology:
Stenosis or narrowing of the aortic or pulmonary valves causes the associated ventricle to hypertrophy; valvular incompetence produces a characteristic heart murmur |
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Term
| right cusp, pulmonary valve |
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Definition
portion of the pulmonary valve which separates the right ventricle from the pulmonary trunk.
Can be confused with: anterior or left pulmonary cusps
To identify: when looking from above, first identify the pulmonary trunk (vessel coming out of right ventricle). Assume anterior side is the one furthest from the heart. This is the anterior valve. Behind it and to the anatomical right is the right cusp.
Attachments: anterior and left pulmonary cusps
Purpose of valve:to prevent backflow of blood into the right ventricle during diastole
Special: auscultation of the pulmonary valve can be detected between the left 2nd and 3rd rib near the sternum
Systolic contraction results in the forceful ejection of blood from the ventricles into the pulmonary or systemic circulation; the AV valves are closed and the aortic and pulmonary valves are opened.
The "second" heart sound in the lub-dub is the closing of the aortic and pulmonary valves.
pathology:
Stenosis or narrowing of the aortic or pulmonary valves causes the associated ventricle to hypertrophy; valvular incompetence produces a characteristic heart murmur |
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Term
| left cusp, pulmonary valve |
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Definition
portion of the pulmonary valve which separates the right ventricle from the pulmonary trunk.
Can be confused with: right or anterior pulmonary cusps
To identify: when looking from above, first identify the pulmonary trunk (vessel coming out of right ventricle). Assume anterior side is the one furthest from the heart. This is the anterior valve. Behind it and to the anatomical left is the left cusp.
Attachments: right and anterior pulmonary cusps
Purpose of valve:to prevent backflow of blood into the right ventricle during diastole
Special: auscultation of the pulmonary valve can be detected between the 2nd and 3rd rib near the sternum
Systolic contraction results in the forceful ejection of blood from the ventricles into the pulmonary or systemic circulation; the AV valves are closed and the aortic and pulmonary valves are opened.
The "second" heart sound in the lub-dub is the closing of the aortic and pulmonary valves.
pathology:
Stenosis or narrowing of the aortic or pulmonary valves causes the associated ventricle to hypertrophy; valvular incompetence produces a characteristic heart murmur |
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Term
| interventricular septum (of right ventricle) |
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Definition
divides the right and left ventricles, made of a membranous part and muscular part
To identify: The interventricular septum is located posterior to the septal papillary muscle
Purpose:to separate the right and left ventricles
Formation: The muscular interventricular septum grows superiorly from the floor of the common ventricle. After the aorticopulmonary septum is complete, the inferior portion of the aorticopulmonary septum fuses with the muscular interventricular septum, thereby forming the superior membranous portion of the interventricular septum (D), thus completing the partitioning of the ventricle. muscular portion=mesoderm, membranous portion=neural crest derived
pathology: Ventricular Septal Defects (VSD) are the most common type of congenital cardiac malformation. They may occur subsequent to defective formation of the aorticopulmonary septum; consequently the membranous portion of the interventricular septum is absent. Alternatively, the muscular portion
of the interventricular septum may fail to form properly.
The communication between the right and left ventricles alters the amount of blood contained in each and there is a mixing of oxygenated and deoxygenated blood. Because the systemic pressure is greater than the pulmonary pressure, blood flows from the left to the right ventricle; this results in pulmonary hypertension. If the situation is left uncorrected, congestive heart failure as well as pulmonary edema may ensue. Ultimately, both ventricles hypertrophy since they receive increased amounts of blood.
Tetralogy of Fallot is a series of four congenital defects that occur together: pulmonary stenosis, a ventricular septal defect, an overriding (enlarged) aorta and right ventricular hypertrophy. An infant with this condition is noticeably cyanotic at birth (“blue baby”). Early corrective surgery involving repair of both the pulmonary stenosis and the ventricular septal defect usually results in a good outcome.
The incomplete division of the aorta and pulmonary trunk, a persistent truncus arteriosus, is accompanied by an interventricular septal defect since the partitioning of these two major vessels and the completion of the interventricular septum are interdependent. There is a substantial amount of deoxygenated blood in the systemic circulation. The overall efficiency of the lungs is reduced due to the amount of oxygenated blood that flows into the pulmonary trunk. Untreated infants fail to thrive and usually do not live longer than
two years. |
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Term
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Definition
a muscular pouch connected to the left atrium of the heart.
Can be confused with: right auricle
To identify: observe the exterior of the left atrium and try to visualize a small appendage protruding from it.
Purpose: Functions as a reservoir for the left atrium
Formation: the smooth wall of the definitive left atrium is formed by the developing pulmonary venous system. The single pulmonary vein that initially arises on the posterior aspect
of the left atrium branches into four vessels that find their way to the developing lungs.
The proximal portions of these veins become incorporated in the atrial wall; the left auricle is all that remains of the original primitive atrial chamber.
Pathology:In atrial fibrillation, blood clots arise from the left atrial appendage in more than 90% of cases. They may dislodge (forming emboli), which may lead to ischemic damage to the brain, kidneys, or other organs supplied by the systemic circulation |
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Term
| orifices of pulmonary veins |
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Definition
the holes of the pulmonary veins as they enter the left atrium.
Can be confused with: pulmonary trunk
To identify: observe the exterior of the left atrium and visualize 2 pairs of vessels entering it.
Purpose: supply oxygenated blood to the left atrium
Formation: the smooth wall of the definitive left atrium is formed by the developing pulmonary venous system. The single pulmonary vein that initially arises on the posterior aspect
of the left atrium branches into four vessels that find their way to the developing lungs.
The proximal portions of these veins become incorporated in the atrial wall; the left auricle is all that remains of the original primitive atrial chamber. |
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Term
| mitral or bicuspid valve (of left atrium) |
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Definition
valve located in the left ventricle that prevents backward blood flow into the left atrium.
Can be confused with: tricuspid valve.
To identify: the clearly defined valve within the left ventricle is the bicuspid valve. You can tell it has 2 cusps by the number of attachments to papillary muscles (2)
Attachments: anterior and posterior papillary muscles
Purpose of valve: to prevent backflow of blood into the left atrium during systole, they open during diastole
Formation: left side of the atrial canal, formed by the presence of the septum intermedium, eventually becomes the bicuspid valve, mesodermal tissue
Special: auscultation of bicuspid valve can be conducted between the 5th and 6th rib near the costal cartilage. The "first" heart sound in the lub-dub is the closing of the tricuspid and bicuspid valves.
Pathology: The bicuspid valve often is affected by infections such as rheumatic fever. Subsequent scarring produces shrinkage and an increase in the thickness of its leaflets and of the chordae tendineae. This results in incomplete closure of the valve, atrioventricular valvular incompetence.
As a consequence, blood regurgitates into the left atrium during systole causing the heart to beat more rapidly and more forcefully. Pulmonary congestion results from the incomplete emptying of the left atrium. |
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Term
| trabeculae carnae (of left ventricle) |
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Definition
rounded or irregular muscular columns which project from the inner surface of the right and left ventricles of the heart
Can be confused with: pectinate muscles of the right and left atrium
To identify: if left ventricle has been opened, the trabeculae carnae are the muscles on the inside of the posterior surface of the ventricle.
Innervation: The Cardiac Plexus contains sympathetic, parasympathetic and visceral afferent fibers. The preganglionic sympathetic neurons originate in the intermediolateral cell column at spinal levels T1 – T5. Some of the preganglionic fibers synapse in sympathetic chain ganglia; the postganglionic fibers travel directly to the cardiac plexus. The majority of preganglionic fibers destined to be part of the cardiac plexus enter the sympathetic chain and travel to the cervical ganglia where they synapse; the long postganglionic fibers that join the cardiac plexus are the cervical cardiac nerves. Sympathetic fibers accelerate the heart rate and increase the force of the heart beat.
The preganglionic parasympathetic fibers are part of the Vagus nerve. Once synapses have occurred in microscopic ganglia within and around the myocardium, the postganglionic fibers act to slow the heart rate and to decrease the force of the heart beat.
The visceral afferent fibers that are part of the Vagus nerve monitor cardiac output, blood pressure and blood chemistry. The visceral afferent fibers that are stimulated by disturbances in cardiac metabolism travel with the sympathetic fibers. Their cell bodies are in the dorsal root ganglia at spinal levels T1 – T5.
Formation: Occurs along with the muscular interventricular septum, which grow superiorly from the floor of the common ventricles; mesodermal in origin
Blood supply: Left Anterior Descending branch of the left coronary artery |
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Term
| anterior papillary muscle (of left ventricle) |
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Definition
connects to the anterior cusp of bicuspid valve.
Can be confused with: posterior papillary muscle.
To identify: anterior papillary muscle is the one that appears closest to the anterior wall of the ventricle
Attachments: Attaches to chordae tendonae of the anterior cusp of the bicuspid valve
contract before the ventricle itself contracts, tightening the chordae tendinea and drawing the cusps of the valve together to prevent backflow of blood into the left atrium
Innervation: Purkinje fibers from the left bundle innervate the anterior papillary muscle of the left ventricle
Formation: papillary muscles form inwardly from the heart wall at the same time as the muscular interventricular septum, from mesodermal tissue
Blood supply: mostly the left anterior descending branch of the left coronary artery but also the circumflex branch |
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Term
| anterior cusp of mitral/bicuspid valve |
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Definition
portion of bicuspid valve located in left ventricle
Can be confused with: posterior cusp of mitral valve.
To identify: the anterior cusp of the mitral valve is located towards the anterior portion of the organism (side closest to aorta)
Attachments: chordae tendineae which attach to the anterior papillary muscle
Purpose of valve: to prevent backflow of blood into the left atrium during systole, they open during diastole
Formation: left side of the atrial canal, formed by the presence of the septum intermedium, eventually becomes the bicuspid valve, mesodermal tissue
Special: auscultation of bicuspid valve can be conducted between the 5th and 6th rib near the costal cartilage. The "first" heart sound in the lub-dub is the closing of the tricuspid and bicuspid valves.
Pathology: The bicuspid valve often is affected by infections such as rheumatic fever. Subsequent scarring produces shrinkage and an increase in the thickness of its leaflets and of the chordae tendineae. This results in incomplete closure of the valve, atrioventricular valvular incompetence.
As a consequence, blood regurgitates into the left atrium during systole causing the heart to beat more rapidly and more forcefully. Pulmonary congestion results from the incomplete emptying of the left atrium. |
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Term
| posterior papillary muscle (of left ventricle) |
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Definition
connects to the posterior cusp of bicuspid valve.
Can be confused with: anterior papillary muscle.
To identify: posterior papillary muscle is the one that appears closest to the posterior wall of the ventricle
Attachments: Attaches to chordae tendonae of the posterior cusp of the bicuspid valve
contract before the ventricle itself contracts, tightening the chordae tendinea and drawing the cusps of the valve together to prevent backflow of blood into the left atrium
Innervation: Purkinje fibers from the left bundle innervate the anterior papillary muscle of the left ventricle
Formation: papillary muscles form inwardly from the heart wall at the same time as the muscular interventricular septum, from mesodermal tissue
Blood supply: mostly the left anterior descending branch of the left coronary artery but also the circumflex branch |
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Term
| posterior cusp of mitral/bicuspid valve |
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Definition
portion of bicuspid valve located in left ventricle
Can be confused with: anterior cusp of mitral valve.
To identify: the posterior cusp of the mitral valve is located towards the posterior portion of the organism
Attachments: chordae tendineae which attach to the posterior papillary muscle
Purpose of valve: to prevent backflow of blood into the left atrium during systole, they open during diastole
Formation: left side of the atrial canal, formed by the presence of the septum intermedium, eventually becomes the bicuspid valve, mesodermal tissue
Special: auscultation of bicuspid valve can be conducted between the 5th and 6th rib near the costal cartilage. The "first" heart sound in the lub-dub is the closing of the tricuspid and bicuspid valves.
Pathology: The bicuspid valve often is affected by infections such as rheumatic fever. Subsequent scarring produces shrinkage and an increase in the thickness of its leaflets and of the chordae tendineae. This results in incomplete closure of the valve, atrioventricular valvular incompetence.
As a consequence, blood regurgitates into the left atrium during systole causing the heart to beat more rapidly and more forcefully. Pulmonary congestion results from the incomplete emptying of the left atrium. |
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Term
| chordae tendineae (of left ventricle) |
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Definition
connective tissue attaching the papillary muscles to the cusps of the mitral valve.
Can be confused with: cusp of mitral valve.
To identify: the stringy part of the connective tissue closest to the papillary muscles are the chordae tendineae; the cusps are more substantial in size.
Attachments: to papillary muscles and to the cusps of the bicuspid
Formation: occurs with the cusps (after the formation of atrial canals)
Pathology: rupture of chordae tendineae can lead to heart murmurs. |
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Term
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Definition
valve responsible for preventing backflow into the left ventricle.
Can be confused with: pulmonary valve
To identify: identify the left ventricle; aortic valve is in the vessel protruding from it.
Purpose of valve:to prevent backflow of blood into the left ventricle during diastole
Special: auscultation of the aortic valve can be detected between the right 2nd and 3rd rib near the sternum
Systolic contraction results in the forceful ejection of blood from the ventricles into the pulmonary or systemic circulation; the AV valves are closed and the aortic and pulmonary valves are opened.
The "second" heart sound in the lub-dub is the closing of the aortic and pulmonary valves.
pathology:
Stenosis or narrowing of the aortic or pulmonary valves causes the associated ventricle to hypertrophy; valvular incompetence produces a characteristic heart murmur |
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Term
| posterior cusp, aortic valve |
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Definition
portion of aortic valve, responsible for preventing backflow into the left ventricle.
Can be confused with: right and left cusp of the aortic valve
To identify: from the top of the heart, locate the aorta. The posterior cusp is the cusp located towards the posterior side of the aorta (is in line with the anterior cusp of the pulmonary valve)
Purpose of valve:to prevent backflow of blood into the left ventricle during diastole
Special: auscultation of the aortic valve can be detected between the right 2nd and 3rd rib near the sternum
Systolic contraction results in the forceful ejection of blood from the ventricles into the pulmonary or systemic circulation; the AV valves are closed and the aortic and pulmonary valves are opened.
The "second" heart sound in the lub-dub is the closing of the aortic and pulmonary valves.
pathology:
Stenosis or narrowing of the aortic or pulmonary valves causes the associated ventricle to hypertrophy; valvular incompetence produces a characteristic heart murmur |
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Term
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Definition
portion of aortic valve, responsible for preventing backflow into the left ventricle.
Can be confused with: left and posterior cusps of the aortic valve
To identify: from the top of the heart, locate the aorta. The posterior cusp is the cusp located towards the posterior side of the aorta. The right cusp is located anteriorly and to the right of the posterior cusp.
Purpose of valve:to prevent backflow of blood into the left ventricle during diastole
Special: auscultation of the aortic valve can be detected between the right 2nd and 3rd rib near the sternum
Systolic contraction results in the forceful ejection of blood from the ventricles into the pulmonary or systemic circulation; the AV valves are closed and the aortic and pulmonary valves are opened.
The "second" heart sound in the lub-dub is the closing of the aortic and pulmonary valves.
pathology:
Stenosis or narrowing of the aortic or pulmonary valves causes the associated ventricle to hypertrophy; valvular incompetence produces a characteristic heart murmur |
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Term
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Definition
portion of aortic valve, responsible for preventing backflow into the left ventricle.
Can be confused with: right and posterior cusps of the aortic valve
To identify: from the top of the heart, locate the aorta. The posterior cusp is the cusp located towards the posterior side of the aorta. The left cusp is located anteriorly and to the left of the posterior cusp.
Purpose of valve:to prevent backflow of blood into the left ventricle during diastole
Special: auscultation of the aortic valve can be detected between the right 2nd and 3rd rib near the sternum
Systolic contraction results in the forceful ejection of blood from the ventricles into the pulmonary or systemic circulation; the AV valves are closed and the aortic and pulmonary valves are opened.
The "second" heart sound in the lub-dub is the closing of the aortic and pulmonary valves.
pathology:
Stenosis or narrowing of the aortic or pulmonary valves causes the associated ventricle to hypertrophy; valvular incompetence produces a characteristic heart murmur |
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