Capsula

== Capsula ==

A capsula (plural: capsulae) is a term used in anatomy and biology to describe a membranous or fibrous structure that encloses an organ, a joint, or other anatomical structures. The term is derived from the Latin word for "small box" or "container."

Types of Capsulae[edit | edit source]

There are several types of capsulae in the human body, each serving different functions:

Joint capsule: This type of capsula surrounds synovial joints, providing stability and containing the synovial fluid that lubricates the joint.
Renal capsule: A tough fibrous layer surrounding the kidney and covered in a layer of perirenal fat.
Glisson's capsule: A layer of connective tissue surrounding the liver.
Bacterial capsule: A polysaccharide layer that lies outside the cell envelope of bacteria, providing protection against phagocytosis.

Functions[edit | edit source]

Capsulae serve several important functions in the body:

**Protection**: They protect the enclosed structures from physical damage and infection.
**Support**: They provide structural support to the organs and joints they enclose.
**Containment**: They help contain fluids, such as synovial fluid in joints, ensuring proper lubrication and function.

Clinical Significance[edit | edit source]

Capsulae can be involved in various medical conditions:

**Capsulitis**: Inflammation of a capsule, often seen in joints such as the shoulder (adhesive capsulitis or "frozen shoulder").
**Capsular contracture**: A complication of breast implants where the capsule around the implant tightens, causing pain and distortion.