(From bursa, a purse). Called also bursts tendinibus subjects, and sacculi mucosi.

It is said that Bellini first observed these bags, but Douglas first described them. Their office is to facilitate the motion of the tendons, where they play upon one another, or upon a bone, and for this purpose they contain a lubricating mucus.

Bell's Surgery, vol. v. 479. Monro's Description of the Burse Mucosa, and their diseases.

Mr. Gooch, in his Observations, takes notice of a wound in one of these bags on the side of the knee, which, from the discharge, he concluded to have been from the bursal ligament, but it healed kindly, and led him to suspect that these bags may be the scat of disorders not yet noticed. He hath also given the following list of them.

1. Deltoides. A large one situated under this muscle, upon the acromion scapulae.

2. Biceps brachii. A small one investing the tubercle of the radius, both on the side where the tendon is fixed, and also on the other side where there is no tendon. It adheres strongly to the whole tubercle, and loosely to part of the supinator brevis, under which it lies, as well as under the tendon of the biceps.

3. Iliacus internus et psoas. A large thin pliable one is found upon the ischium, beneath the tendons of the iliacus internus and psoas, as they pass down to their insertions in the os femoris. It is attached to these tendons, and to the anterior surface of the capsular ligament; and this sacculus sometimes communicates with the joint.

4. Latissimus dorsi et teres major. One is situated between the extremities of the tendons of these muscles, adhering strongly to them.

5. Gluteus maximus. A large thin one, firmly connected by a small part of it to the back of the trochanter, immediately under the termination of the gluteus medius, and loosely attached to the rest of the trochanter and the tendon of the gluteus maximus.

6. Gluteus medius. A small one situated between the termination of its tendon and that of the pyriformis, adhering to both.

7. Glute us MIni Mus. A small thin one, attached to its tendon and the trochanter major.

8. Gemini. A small one between them and the termination of the obturator internus, connected to both, and to that part of the capsula of the joint which lies under the gemini.

9. Biceps cruris. One is situated between the end of its tendon exteriorly, and the capsular ligament of the knee, adhering to both.

10. Semimembranous. A small one lies between its tendon, which runs between the inner condyle of the tibia, and the capsular ligament of the joint.

11. Cruralis et vasti. Behind the tendons of the cruralis and vasti there is a thin but large one, connected to those tendons before they join, and, after their junction, it is fixed to the patella. It also adheres to the capsula of the joint that expands itself over the bone.

12. Gracilis, sartorius, and semitendinosus. Under the extremities of the tendons of these muscles is a large one, adhering to them on one side, and on the other to the capsular ligament of the knee, and on the side where these tendons play.

13. Gemellus. A large one lies under its inner head, firmly attached to its tendinous origin, also to the extremity of the semitendinosus, and the capsula of the knee near the anterior condyle.

14. Soleus. The tendon of the soleus passes over the upper part of the os calcis, between which and the bone lies a large sacculus, and near that is found a glandular body which furnishes a mucous fluid for the more effectual lubrication of these parts, that are in such constant motion in walking.

15. Tibialis anticus. A small one is fixed to the tendon a little before its termination, where it plays on the top of the foot.

16. Peroneus Longus. One lies under the tendon of this muscle, where it plays over the os cuneiforme, on the outside of the foot.