MICROANATOMY

Detailed explanation-1: -The apex (the most inferior, anterior, and lateral part as the heart lies in situ) is located on the midclavicular line, in the fifth intercostal space . It is formed by the left ventricle.

Detailed explanation-2: -The base of the heart is located at the level of the third costal cartilage, as seen in Figure 1. The inferior tip of the heart, the apex, lies just to the left of the sternum between the junction of the fourth and fifth ribs near their articulation with the costal cartilages.

Detailed explanation-3: -In a pyramid or cone, the apex is the vertex at the “top” (opposite the base). In a pyramid, the vertex is the point that is part of all the lateral faces, or where all the lateral edges meet.

Detailed explanation-4: -The apex beat or apical impulse is the palpable cardiac impulse farthest away from the sternum and farthest down on the chest wall, usually caused by the LV and located near the midclavicular line (MCL) in the fifth intercostal space.

Detailed explanation-5: -The base of tbe heart (basis cordis), directed upward, backward, and to the right, is separated from the fifth, sixth, seventh, and eighth thoracic vertebræ by the esophagus, aorta, and thoracic duct. It is formed mainly by the left atrium, and, to a small extent, by the back part of the right atrium.