The sternal region refers to the central area of the chest, encompassing the sternum, commonly known as the breastbone. This anatomical feature is a recognizable part of the human torso, forming a protective structure in the upper body.
Understanding Its Location
The sternal region is centrally located on the front of the thorax, in the midline of the chest. It extends vertically from just below the neck to the upper abdomen. Individuals can easily locate this flat bone by feeling the hard structure in the middle of their chest. It sits between the ribs, which connect to it, and also has a relationship with the clavicles, or collarbones, at its upper portion.
The sternum forms the front part of the rib cage, creating a prominent bony structure. Its position makes it a superficial landmark, easily identifiable and palpable. This central placement ensures its involvement in the overall structure of the chest, connecting various components of the thoracic skeleton.
Anatomy of the Sternum
The sternum is a flat, T-shaped bone divided into three distinct segments. The uppermost part is the manubrium, which is broad and somewhat quadrangular in shape. Below the manubrium lies the body of the sternum, which is the longest and most flattened section. The smallest and most inferior segment is the xiphoid process.
A notable anatomical landmark is the sternal angle, or Angle of Louis, which is the projection formed where the manubrium joins the body of the sternum. This angle is palpable as a transverse ridge on the anterior chest wall. It serves as a reference point for identifying the second pair of ribs, which articulate at this specific location. The xiphoid process is largely cartilaginous in structure, especially in younger individuals, and gradually ossifies into bone with age.
Vital Role in the Body
The sternum performs several functions. Its primary role is to shield the heart, lungs, and major blood vessels from external physical impact and injury.
The sternum also serves as a central attachment point for the ribs. This connection is made via costal cartilages, which allow for a degree of flexibility in the chest wall. Various muscles of the chest, neck, and abdomen, including parts of the diaphragm, also attach to the sternum, contributing to overall body movement and stability. The flexibility provided by the costal cartilages, where the ribs meet the sternum, contributes to the expansion and contraction of the chest cavity during the process of breathing.