Tubercle (bone)

A small, rounded projection on a bone

Tubercle is a term used in anatomy to describe a small, rounded projection or protuberance on a bone. Tubercles serve as attachment points for muscles and ligaments, playing a crucial role in the musculoskeletal system.

Structure

Tubercles are typically found on the surface of bones and vary in size and shape depending on their location and function. They are composed of compact bone and are often located near joints, where they provide leverage and support for muscle attachment.

Function

The primary function of a tubercle is to serve as an attachment site for muscles and ligaments. This allows for the transmission of force from muscles to bones, facilitating movement. Tubercles also contribute to the stability of joints by providing additional surface area for ligament attachment.

Examples

Several bones in the human body feature prominent tubercles:

• The humerus has the greater and lesser tubercles, which serve as attachment points for the muscles of the rotator cuff.
• The femur has the adductor tubercle, which is the attachment site for the adductor magnus muscle.
• The ribs have tubercles that articulate with the transverse processes of the vertebrae.

Clinical significance

Tubercles can be involved in various medical conditions. For example, the greater tubercle of the humerus is a common site for rotator cuff tears. Additionally, fractures involving tubercles, such as the tuberosity of the fifth metatarsal, can occur due to trauma or overuse.

X-ray showing a fracture of the tuberosity of the fifth metatarsal.

Related pages

• Bone
• Muscle
• Ligament
• Joint

References

• Gray, Henry. Gray's Anatomy: The Anatomical Basis of Clinical Practice. 41st edition. Elsevier.
• Moore, Keith L., et al. Clinically Oriented Anatomy. 7th edition. Lippincott Williams & Wilkins.