|WikiProject Medicine / Cardiology||(Rated Start-class, Mid-importance)|
I find the following statements more than dubious:
The valve between the left atrium and left ventricle of the heart.
The mitral valve has two cusps/leaflets (the anteromedial leaflet and the posterolateral leaflet) and gaurds an opening that normally admits two fingers.
- A very inaccurate measurement. Even if modified to an opening that in an adult admits two medium sized adult fingers it's not necessarily true.
- No, they don't. Yes, I know it's "common wisdom", but it's not true. Look at any photograph of a specimen and see for yourself.
Thus when the ventricle contracts the chorde pull the two cusps together closing the opening.
- If you look at the orientation of the chordae and papillary muscles you'll see that they pull almost in parallell. They can not pull the cusps toghether. The pressure against the cusps does that. --Ekko 19:07, 29 May 2006 (UTC)
Mitral valve anatomy & chordae
I agree with the dispute. Chordae do not pull on the valve to close, instead they prevent its prolapse, while the motion to closure is due to the pressure increase in the left ventricle. This is well documented in medical and scientific literate.
A current topic of research relates to the structure and function of the valve. The valve is densly innervated by TH (motor) and CgRP (sensory) nerves. These nerves have been tentivly shown to allow the valve to activly contract. It is possible that these small contractions assist in efficiency of blood passage.
Please go ahead and make this change. It is not only more accurate, but more importantly, unchallenged : ) Reid Sullivan 21:15, 17 August 2006 (UTC)
In fact, it is the pressure from the blood flow against the valve that allows it to form during development. The valve begins as a small lump of tissue and as blood passes by it, different areas of the lump detect different flow pressure. The valve then changes morphology to adapt to this flow. —Preceding unsigned comment added by 188.8.131.52 (talk) 03:51, 5 June 2008 (UTC)