Osteology of Ribs | Anatomy Lectures | Medical Video Lectures

The ribs are long, curved bones that form the ribcage, providing protection to the thoracic organs, including the heart and lungs. There are 12 pairs of ribs in the human body, and they can be categorized into three types: true ribs, false ribs, and floating ribs. Here’s an overview of the osteology (structure and anatomy) of ribs:

General Structure of a Rib:

1. Head (Caput):
   • The head of the rib is the posterior end that articulates with the costal facet of the corresponding thoracic vertebra.
   • The head typically has two facets: one for the corresponding vertebral body and one for the intervertebral disc.
2. Neck (Collum):
   • The neck is a short, constricted region located between the head and the tubercle.
3. Tubercle (Tuberculum):
   • The tubercle is a small bump on the rib that articulates with the transverse process of the corresponding thoracic vertebra.
   • It has an articular facet for this articulation.
4. Shaft (Body):
   • The shaft is the long, curved portion of the rib.
   • The external surface is convex, while the internal surface is concave.
5. Costal Angle:
   • The costal angle is the point where the rib starts to curve anteriorly. It is often used as a landmark in clinical examinations.
6. Costal Groove:
   • The costal groove is located on the inferior border of the rib.
   • It contains the intercostal vessels (vein, artery, and nerve), providing protection and support.

Types of Ribs:

1. True Ribs (Vertebrosternal Ribs):
   • The first seven pairs of ribs are true ribs.
   • They articulate directly with the sternum via costal cartilages.
   • Each true rib has its own costal cartilage that attaches to the sternum.
2. False Ribs:
   • a. False Ribs with Cartilaginous Fusion to the Sternum (Vertebrochondral Ribs):
     • Ribs 8 to 10 are false ribs with indirect attachment to the sternum.
     • They do not attach directly to the sternum but have their costal cartilages fused to the cartilage of the rib above.
   • b. False Ribs without Direct Attachment to the Sternum (Vertebral Ribs or Floating Ribs):
     • Ribs 11 and 12 are floating ribs.
     • They do not have any attachment to the sternum or to the costal cartilage of another rib.

Articulations:

1. Costovertebral Joints:
   • The articulation between the head of the rib and the costal facets of the corresponding thoracic vertebra.
2. Costotransverse Joints:
   • The articulation between the tubercle of the rib and the transverse process of the corresponding thoracic vertebra.
3. Costosternal Joints:
   • The articulation between the costal cartilage of true ribs and the sternum.

Function:

• Ribs protect vital organs in the thoracic cavity, including the heart and lungs.
• They assist in the breathing process by providing structural support to the thoracic cavity and attachment points for respiratory muscles.

Understanding the osteology of ribs is essential for medical professionals, particularly in fields such as anatomy, orthopedics, and radiology. It provides a foundation for diagnosing and treating conditions related to the ribcage and thoracic region.