Structural and Functional Features of the Sternum

The sternum, or breastbone, is a vital component of the thoracic skeleton, providing protection to essential thoracic organs while serving as an anchor for the ribs and clavicles.

Anatomical Overview

The sternum consists of three distinct sections:

• Manubrium: The uppermost part, articulating with the clavicles and the first ribs.
• Body: The central, elongated portion to which most ribs are attached.
• Xiphoid Process: The smallest, inferior segment, varying in shape among individuals.

Functional Importance

The sternum serves several physiological roles, including:

• Protection of vital organs such as the heart and lungs.
• Structural support for the ribcage and thoracic cavity.
• Attachment site for muscles involved in respiration and upper limb movement.

Typical and Atypical Rib Features

Ribs are categorized based on their structural and functional attachments:

Typical Ribs

• Include ribs 3-9.
• Consist of a head, neck, tubercle, and shaft.
• Articulate with the vertebrae at two points.

Atypical Ribs

The first, second, tenth, eleventh, and twelfth ribs exhibit distinct anatomical characteristics:

• First rib: Broader and shorter, with a single articulation.
• Second rib: Thinner and longer than the first, with notable tuberosities.
• Floating ribs (11th & 12th): Lack anterior attachments.

Clinical Relevance

Disorders related to the sternum and ribs include:

• Pectus excavatum (concave chest deformity).
• Pectus carinatum (protruding sternum).
• Rib fractures impacting respiratory efficiency.

Understanding the sternum and rib anatomy helps in diagnosing and managing thoracic injuries efficiently.