Scapula
- The scapula is a flat triangular bone on the posterolateral thoracic wall, usually spanning ribs 2 through 7.
- Its borders are superior, medial, and lateral, and its angles are superior, inferior, and lateral.
- The anterior costal surface contains the subscapular fossa.
- The posterior spine divides the bone into supraspinous and infraspinous fossae.
- A fossa is a shallow depression; the supraspinous fossa lies above the scapular spine and the infraspinous fossa lies below it, giving broad surfaces for rotator-cuff muscle attachment.
- The spine expands laterally into the acromion, which articulates with the clavicle and overhangs the shoulder.
- The lateral angle contains the glenoid cavity for the humeral head.
- The glenoid cavity is the shallow shoulder socket; its shallowness allows wide arm movement but means the labrum, capsule, ligaments, and rotator cuff must add stability.
- The supraglenoid tubercle gives origin to the long head of biceps brachii.
- The infraglenoid tubercle gives origin to the long head of triceps brachii.
- The coracoid process projects anteriorly and anchors coracobrachialis, the short head of biceps brachii, pectoralis minor, and several ligaments.
- A process is a bony projection; the coracoid process acts like an anterior hook where muscles and ligaments attach to move or stabilize the scapula and shoulder.
- The suprascapular notch transmits the suprascapular nerve beneath the superior transverse scapular ligament.
- The suprascapular artery usually passes superior to that ligament.
- At the suprascapular notch, the suprascapular nerve usually travels under the superior transverse scapular ligament, while the artery usually travels over it.
Use Hide Bold Terms to cover authored terms, or Hide Every Word to cover every word in the block. Show One reveals the next hidden term or word in reading order without expanding the whole block. In Hide Main, hover a visible term to preview the full bullet.