Intermediate - Heart Valves: Difference between revisions

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There are four valves in the adult heart, depicted below.  There are ''two'' AV valves which comprise leaflets as well as the structures that tether these leaflets to the ventricular walls.  The '''aortic''' and '''pulmonary''' valves, termed the '''semilunar valves''' are located in the aorta and pulmonary trunk respectively.  They are each made of ''three'' cusps.
[[Image:HeartILP_draft_adultvalves.jpg|thumb|center|upright=2.5|Adult Heart Valves]]


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|[[Image:HeartILP_draft_semilunarlongitudinal.jpg|thumb|upright=2|Development of the semilunar cusps]]
|[[Image:HeartILP_draft_semilunarlongitudinal.jpg|thumb|upright=2|Development of the semilunar cusps]]
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The AV valves begin to form between the fifth and eighth weeks of development.  The valve leaflets are attached to the ventricular walls by thin fibrous chords, the chordae tendineae, which insert into small muscles attached to the ventricle wall, the papillary muscles.  These structures are sculpted from the ventricular wall.  The left AV valve has anterior and posterior leaflets and is termed the bicuspid or mitral valve.  The right AV valve has a third, small, septal cusp and thus is called the tricuspid valve.  These concepts are depicted on the left.




The aortic and pulmonary valves, termed the semilunar valves, are formed from the bulbar ridges and subendocardial valve tissue.  The primordial semilunar valve consists of a mesenchymal core covered by endocardiumExcavation occurs, thinning the valve tissue thus creating its final shape (see right).  These valves form the four valves of the adult heart, depicted below.
The AV valves begin to form between the fifth and eighth weeks of development.  The left AV valve has ''anterior'' and ''posterior'' leaflets and is termed the '''bicuspid''' or '''mitral''' valve.  The right AV valve has a third, small, ''septal'' cusp and thus is called the '''tricuspid''' valve.  The '''valve leaflets''' are attached to the ventricular walls by thin fibrous chords, the '''chordae tendineae''', which insert into small muscles attached to the ventricle wall, the '''papillary muscles'''These structures are sculpted from the ventricular wall (see left).


[[Image:HeartILP_draft_adultvalves.jpg|thumb|center|upright=2.5|Adult Heart Valves]]


The semilunar valves are formed from the '''bulbar ridges''' and subendocardial valve tissue.  The primordial semilunar valve consists of a mesenchymal core covered by endocardium.  Excavation occurs, thinning the valve tissue thus creating its final shape (see right).


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Revision as of 10:25, 3 November 2009

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Begin Intermediate: Primordial Heart Tube  Heart Tube Looping  Atrial Ventricular Septation  Outflow Tract  Heart Valves  Cardiac Abnormalities  Vascular Overview


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There are four valves in the adult heart, depicted below. There are two AV valves which comprise leaflets as well as the structures that tether these leaflets to the ventricular walls. The aortic and pulmonary valves, termed the semilunar valves are located in the aorta and pulmonary trunk respectively. They are each made of three cusps.

HeartILP draft avvalves.jpg
Development of the mitral and tricuspid valves
Development of the semilunar valves
Development of the semilunar cusps


The AV valves begin to form between the fifth and eighth weeks of development. The left AV valve has anterior and posterior leaflets and is termed the bicuspid or mitral valve. The right AV valve has a third, small, septal cusp and thus is called the tricuspid valve. The valve leaflets are attached to the ventricular walls by thin fibrous chords, the chordae tendineae, which insert into small muscles attached to the ventricle wall, the papillary muscles. These structures are sculpted from the ventricular wall (see left).


The semilunar valves are formed from the bulbar ridges and subendocardial valve tissue. The primordial semilunar valve consists of a mesenchymal core covered by endocardium. Excavation occurs, thinning the valve tissue thus creating its final shape (see right).

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