Septal leaflet of right atrioventricular valve
Cuspis septalis valvae atrioventricularis dextrae
The leaflet of the tricuspid valve attached along the interventricular septum, on the medial side of the right atrioventricular opening.
At a glance
- English
- Septal leaflet of right atrioventricular valve
- Latin (TA2)
- Cuspis septalis valvae atrioventricularis dextrae
- System
- Heart
- Region
- Trunk
- Side
- Single, on the midline
About the septal leaflet of right atrioventricular valve
The septal leaflet is one of the three cusps of the right atrioventricular (tricuspid) valve, which separates the right atrium from the right ventricle. As its name suggests, it lies against the interventricular septum, on the medial side of the opening, with the anterior leaflet in front and the inferior leaflet below.
Its base is fixed partly to the fibrous ring and partly directly to the septum itself. A distinctive feature of the tricuspid valve is that this attachment sits a little nearer the apex of the heart than the attachment of the anterior leaflet of the mitral valve on the other side of the septum. The wall between the two lines is the atrioventricular septum, partly membranous and partly muscular, which separates the right atrium from the left ventricle. The leaflet is usually shorter from base to edge than the anterior leaflet and its movement is restricted by its many short cords.
Chordae tendineae reach it from small septal papillary muscles and from the septal wall directly, and also from the inferior papillary muscle. In systole the leaflets meet and seal the orifice so that blood leaves the ventricle only through the pulmonary valve.
The septal leaflet has important neighbours. The atrioventricular node lies in the triangle of Koch just above its attachment, and the bundle of His runs close beneath it. Surgery to the leaflet, or closure of nearby septal defects, therefore carries a risk of heart block. In Ebstein anomaly, a congenital disorder, the septal and inferior leaflets are attached far down inside the ventricle, so part of the ventricle behaves as if it were atrium.
Function and supply
- Begins at
- The septal part of the right fibrous ring and the adjoining interventricular septum, slightly apical to the mitral attachment.
- Ends at
- Its free edge and ventricular surface are held by chordae tendineae from the septal and inferior papillary muscles and from the septal wall.
- Function
- Closes against the anterior and inferior leaflets in ventricular systole to prevent backflow into the right atrium; opens in diastole.
Anthromica
See the septal leaflet of right atrioventricular valve where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
