Overview
This lecture covers the anatomical features, orientation, and major landmarks of the scapula (shoulder blade), a key bone in the pectoral girdle.
Orientation and Sides of the Scapula
- The scapula, or shoulder blade, is a flat bone located on the back (posterior) side of the shoulder.
- The spine of the scapula is the largest ridge and is always on the posterior (back) side.
- The acromion process flares out from the spine and is always lateral (towards the shoulder’s outer edge).
- The coracoid process, a beak-like structure, is always on the superior (upper) end.
- The suprascapular notch is also found on the superior border.
- Knowing the positions of the spine, acromion, and coracoid process helps identify left versus right scapula.
Major Structures and Markings
- The glenoid fossa is a thumbprint-like depression that articulates with the humerus (upper arm bone).
- Above the glenoid fossa is the supraglenoid tubercle; below it is the infraglenoid tubercle.
- The supraspinous fossa is a shallow groove above the spine; the infraspinous fossa is below the spine.
- The subscapular fossa is a broad shallow depression on the anterior (front) surface.
- The superior angle is the uppermost tip of the scapula; the inferior angle is the lowermost tip.
- The scapula has three borders: medial (closer to the spine), lateral (toward the arm), and superior.
Key Terms & Definitions
- Scapula — Flat, triangular bone of the shoulder, also known as the shoulder blade.
- Spine of the scapula — Prominent ridge on the posterior surface.
- Acromion — Lateral, flared extension of the spine forming the tip of the shoulder.
- Coracoid process — Superior, hook-like projection on the scapula.
- Glenoid fossa — Socket that articulates with the head of the humerus.
- Supraspinous fossa — Shallow depression above the spine.
- Infraspinous fossa — Shallow depression below the spine.
- Subscapular fossa — Anterior surface groove.
- Supraglenoid tubercle — Bump above the glenoid fossa.
- Infraglenoid tubercle — Bump below the glenoid fossa.
- Superior angle — Top tip of the scapula.
- Inferior angle — Bottom tip of the scapula.
- Medial border — Edge closest to the spine.
- Lateral border — Edge closest to the arm.
- Superior border — Top edge.
- Suprascapular notch — Indentation along the superior border for nerve passage.
Action Items / Next Steps
- Review labeled diagrams of the scapula and practice identifying the key landmarks discussed.
- Memorize the orientation markers to distinguish left from right scapula.
- Prepare for further study of muscle attachments and functional anatomy.