Final answer:
The sternal angle is located at the junction between the manubrium and the body of the sternum, corresponding to the second thoracic vertebra (T2) level. It is an essential landmark for identifying rib levels and other anatomical features, such as the bifurcation of the trachea.
Step-by-step explanation:
The sternal angle, also known as the angle of Louis, is located at the junction line between the manubrium and body of the sternum, serving as the site for the attachment of the second rib to the sternum. This anatomical landmark corresponds to the level of the second thoracic vertebra (T2) posteriorly. The sternal angle is an important clinical landmark because it lies at the level where the trachea bifurcates into the primary bronchi, and it also aids in the counting of the ribs, as the first rib is often difficult to palpate due to its position behind the clavicle.
Stemal Anatomy
The sternum is an elongated, flattened bone located at the center of the anterior chest, forming the front of the rib cage and consisting of three parts: the manubrium, body, and xiphoid process. The manubrium, the wider, superior portion, features the jugular notch and clavicular notches, sites for articulation with the clavicles and first ribs. The elongated central portion of the sternum is the body, which receives direct attachments from the costal cartilages of ribs 2-7 and articulates directly with the thoracic vertebrae.