Tubercle

A small, rounded projection or nodule found in various biological contexts

A tubercle is a small, rounded projection or nodule that can be found in various biological contexts. The term is used in anatomy, botany, and pathology to describe different structures that share a similar appearance.

Anatomy

In anatomy, a tubercle is a small, rounded prominence on a bone, often serving as an attachment point for muscles or ligaments. For example, the greater tubercle and lesser tubercle are found on the humerus bone of the upper arm, providing attachment sites for the rotator cuff muscles.

Botany

In botany, tubercles are small, wart-like projections found on the surface of certain plants. They can be seen on the surface of some cacti, such as those in the genus Mammillaria. These tubercles can help in identifying species and may play a role in water storage or protection.

Mammillaria marksiana showing prominent tubercles.

Pathology

In pathology, a tubercle refers to a small, nodular lesion, especially one associated with tuberculosis. These lesions are formed by the aggregation of immune cells attempting to wall off the infection caused by the bacterium Mycobacterium tuberculosis.

Zoology

In zoology, tubercles can refer to small, rounded protuberances on the skin or shell of an animal. For example, some dinosaurs had skin with tubercles, which are sometimes preserved in fossilized skin impressions.

Fossilized skin impression of Edmontosaurus showing tubercles.

Marine Biology

In marine biology, tubercles can be found on the surface of certain marine organisms, such as the nudibranch Phyllidia. These structures can serve various functions, including protection and sensory perception.

Phyllidia nudibranch with visible tubercles.

Related pages

• Tuberculosis
• Cactus
• Bone anatomy