internal features (left ventricle, anatomy)

Last reviewed 01/2018

Usually, the inside of the left ventricle demonstrates features corresponding to the different embryological origins of the chamber:

• part derived from the primitive ventricle:
• forms the more muscular, thick-walled and rough part of the ventricle that lie inferiorly and to the left
• trabeculae carneae: particularly prominent and form a reticular network that is very prominent towards the apex
• muscular part of interventricular septum anteriorly and medially
• two papillary muscles very prominent
• part derived from absorbed truncus arteriosus of development:
• forms the section to the right and superiorly that is smooth-walled
• includes:
• smooth part of interventricular septum
• aortic vestibule
• aortic valve lying superiorly
• mitral valve lying posteriorly and to the right

In terms of the the topography of the chamber:

• the inflow - mitral - and outflow - aortic - valves are in close apposition in the superior 'basal' part of the chamber:
• they are separated only by the anterior cusp of the mitral valve and the fibrous subaortic curtain
• therefore, the anterior leaflet of the mitral valve is modified to permit the flow of blood over both its atrial and ventricular surfaces - see submenu
• the arrangement should be contrasted with the right ventricle - there is almost a complete reversal of the direction of blood flow within the left ventricle between diastole and systole
• in cross section, the chamber is approximately circular