ANAT 315 Lecture Notes - Lecture 8: Glenoid Labrum, Coracohumeral Ligament, Levator Scapulae Muscle
2 Oct 2017
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Classified as synovial, triaxial, ball and socket flexion/extension, abduction/adduction, medial/lateral rotation. Glenoid fossa makes a shallow, pear-shaped depression at the scapula. Fossa is anterolaterally and provides a socket that"s smaller than the ball of the head of the humerus (1/3 of a sphere; covered in hyaline cartilage) Articular contact is enhanced by a lip of fibrocartilage surrounding the perimeter of the glenoid fossa - the glenoid labrum. Humerus has a little contact with the scapula => hella weak but hella mobile glenoid labrum. Flexors: anterior deltoid, clavicular head of pec major. Abductors: lateral head of deltoid and all of deltoid, supraspinatus. Medial rotation: pec major, lats, teres major, Medial rotation: pec major, lats, teres major, subscapularis. Capsule is extremely loose; ligaments are very weak except the coracohumeral ligament. Greatest contribution to the strength are the rotator cuff muscles coracohumeral pec minor. Most of the arteries supplying the joint with blood come from the axillary artery.
