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