what is the anatomical name for the large flat bone at the front of the chest

The sternocostal head of the pectoralis major muscle attaches on the lateral sides of its anterior surface. There are smaller facets, known as demifacets, for articulation with parts of the costal cartilage of the 2 nd and 7 th ribs. Its lateral borders or edges are marked by numerous articular facets, which articulate with the costal cartilages of the 3 rd – 6 th ribs.

The anterior surface of the body is convex, whereas its posterior surface is concave. It is flat and elongated, articulating with the manubrium superiorly and the xiphoid process inferiorly, forming the manubriosternal joint and xiphisternal joint, respectively. The body of the sternum, also known as gladiolus, is the largest part of the sternum. The superior sternopericardial ligament connects the heart’s covering, the pericardium, to the manubrium. The second pair of costal cartilage attaches to the sternum at the lower border of the manubrium. However, its posterior surface gives attachment to sternohyoid and sternothyroid muscles. The sternal fibers of sternocleidomastoid and pectoralis major muscle get attached to the anterior surface of the manubrium. It articulates with the body of the sternum, forming the sternal angle or Angle of Louis with a thin layer of cartilage in between.

The inferior portion or lower border of the manubrium is narrow and rough. It also features a demifacet or half-facet for articulation with a part of the costal cartilage of the 2 nd rib. The lateral edges or lateral borders of the manubrium bear facets for articulation with the costal cartilage of the 1 st rib. These fossae articulate with the medial ends of the collar bones, forming the sternoclavicular joints. On either side of the jugular notch, two other large fossae, known as clavicular notches, are present, projected upward and laterally. The top part or superior border of the manubrium is concave, producing a depression called the jugular notch or suprasternal notch. It is large and quadrangular or trapezoid in shape, bearing several important bony landmarks.

What is the anatomical name for the large flat bone at the front of the chest