Intermediate - Heart Valves: Difference between revisions

From Embryology
No edit summary
No edit summary
Line 8: Line 8:




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.
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]]
[[Image:HeartILP_draft_adultvalves.jpg|thumb|center|upright=2.5|Adult Heart Valves]]
Line 26: Line 26:




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 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).





Revision as of 12:55, 6 November 2009

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


Cardiac Embryology     Begin Basic     Begin Intermediate     Begin Advanced  


HeartILP draft itimeline.jpg


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).

Back to Outflow Tract Division Next: Developmental Abnormalities
Go to this section in the advanced level