Structural and Functional Features of the Sternum

Introduction

The sternum, commonly known as the breastbone, is a flat, elongated bone that lies at the center of the thoracic cavity, providing structural support and protection for vital organs such as the heart and lungs.

Structural Features of the Sternum

The sternum consists of three main parts:

• Manubrium: The uppermost section that articulates with the clavicles and first ribs.
• Body: The longest part, forming the bulk of the sternum and serving as a connection point for ribs.
• Xiphoid Process: The small, cartilaginous extension at the lower end that becomes ossified with age.

Functional Features of the Sternum

• Protects underlying organs, including the heart and lungs.
• Acts as a central attachment site for ribs and pectoral muscles.
• Facilitates respiration by providing structural integrity for thoracic expansion.

Classification of Ribs

The human rib cage comprises 12 pairs of ribs, categorized into three types:

• True Ribs (1-7): Directly attached to the sternum via costal cartilage.
• False Ribs (8-10): Indirectly attached to the sternum by connecting to the cartilage of the seventh rib.
• Floating Ribs (11-12): Not attached to the sternum, providing flexibility and protection for abdominal organs.