LEFT VENTRICLE OF HEART
The left ventricle forms the left posterior part of the ventricular mass. It is more regularly conical and its wall is much thicker than the right ventricle.
It forms the entire posterior contour of the heart and carries the apex of the heart. The base is continuous with the left atrium and the aorta.
It is circular on cross section. The cavity appears smaller than that of the right ventricle in the dead animal on account of the great contraction of its wall.
- The following features are seen in the interior-
- The endocardium.
- The moderator band commonly two large ones, which are more tendinous and branched.
- Fewer trabeculae carneae.
- Two large muscular papillaris which are compound and one on either side.
- The chordae tendinae are fewer but larger than those of the right ventricle.
- The left atrio-ventricular opening is guarded by the bicuspid or mitral valve consisting of two cusps, anterior and posterior. Of which, the anterior is between the aortic vestibule and left atrio-ventricular opening. The accessory cusps are two or three in number.
- The aortic opening is guarded by the aortic valve, composed of three semi-lunar cusps, one cusp is anterior and the others right and left posterior in position. In bovines visceral bones named os cordis are present at the base of the aortic ring. Two bones, right and left of which the right os cordis is larger than the left.
- The free edge of each cusp contains a small central nodule of fibrous tissue.
- The interventricular septum is placed obliquely, so that the convex surface faces forward and to the right and bulges into the right ventricle; the concave surface, looks backwards, and to the left and faces into the left ventricle. Hence the right ventricle appears crescentic whereas the left is circular in cross section.
