What is "enthesis"

n. (context anatomy English) The point at which a tendon, ligament, or muscle inserts into a bone.

The enthesis (plural: entheses) is the connective tissue between tendon or ligament and bone.

There are two types of entheses: Fibrous entheses and fibrocartilaginous entheses.

In a fibrous enthesis, the collagenous tendon or ligament directly attaches to the bone, whereas the fibrocartilaginous interface encompasses four transition zones:

1. Tendinous area displaying longitudinally oriented fibroblasts and a parallel arrangement of collagen fibres
2. Fibrocartilaginous region of variable thickness where the structure of the cells changes to chondrocytes
3. Abrupt transition from cartilaginous to calcified fibrocartilage—often called 'tidemark' or 'blue line'
4. Bone