Scapula

Definition

A flat triangular bone

Belongs to shoulder girdle

Situation

Lies on the posterior chest wall superficial to the ribs and separated from them by muscles

Features

At the lateral angle a shallow articular surface - the glenoid cavity

It articulates with the head of humerus ® shoulder joint

Posteriorly there is an oblique ridge called spinous process

Spinous process at the lateral angle projects to form the acromion process

Acromion process articulates medially with the clavicle to form the acromioclavicular joint.

A projection from the upper border of the bone called coracoid process gives attachments to muscles : coracobrachialis, short head of biceps brachii

On the dorsum : supraspinatus and infraspinatus muscels take origin

On the ventral surface : subscapularis muscle originates

The other muscles that are attached to the scapula are as in the pictures shown below