Tendon sheaths . Tendon sheaths . are lined with dense irregular connective tissue help anchor the tendon to the muscle are extensions of periosteum act as friction-reducing structures

Tendon sheaths act as friction-reducing structures.

Explanation:

Tendon sheaths are fibrous tissue that is around tendons to protect and make the movements of these smoother. For example, they reduce the friction of the flexors and extensors tendons of the hand. These are tendons that we constantly use to open and close our hands when we want to grab objects. Without the sheath, the tendons will not move easily, and due to the excessive use, there can be inflammation.

The sheats have two layers, one internal, which is a synovial one that produces synovial fluid to lubricate the tendon, and the external, which is a fibrous layer.

that is true   : ) hope this you

not too sure but maybe in the hot springs.