The atrioventricular septum is a
septum
In biology, a septum (Latin language, Latin for ''something that encloses''; septa) is a wall, dividing a Body cavity, cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate.
Examples
Hum ...
of the heart between the
right atrium
The atrium (; : atria) is one of the two upper chambers in the heart that receives blood from the circulatory system. The blood in the atria is pumped into the heart ventricles through the atrioventricular mitral and tricuspid heart valves.
...
(RA) and the
left ventricle
A ventricle is one of two large chambers located toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium, an adjacent chamber in t ...
(LV).
Although the name "atrioventricular septum" implies any septum between an atrium and a ventricle, in practice the divisions from RA to RV and from LA to LV are mediated by valves, not by septa. Also, there is usually no communication between the LA and the RV.
Structure
It has a membranous and muscular part.
When considering only the membranous septum, it is also known as the "atrioventricular component of the membranous septum".
Development
It is formed by the union of the dorsal AV cushion and ventral AV cushion.
This septum divides the atrioventricular canal.
Clinical relevance
In some cases, defects can be identified with an
echocardiogram
Echocardiography, also known as cardiac ultrasound, is the use of ultrasound to examine the heart. It is a type of medical imaging, using standard ultrasound or Doppler ultrasound. The visual image formed using this technique is called an echo ...
.
Incomplete formation of the
endocardial cushions
Endocardial cushions, or atrioventricular cushions, refer to a subset of cells in the development of the heart that play a vital role in the proper formation of the heart septa.
They develop on the atrioventricular canal and conotruncal region of ...
can lead to
atrioventricular septal defect
Atrioventricular septal defect (AVSD) or atrioventricular canal defect (AVCD), also known as "common atrioventricular canal" or "endocardial cushion defect" (ECD), is characterized by a deficiency of the atrioventricular septum of the heart that c ...
s, such as an
ostium primum defect.
See also
References
External links
* https://web.archive.org/web/20091030081540/http://www.acc.org/membership/community/pediatric/opinion_apr03/Slide11.JPG
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Cardiac anatomy