Overview
This lecture introduces the scapula (shoulder blade), highlights its major anatomical landmarks, and explains the importance of understanding these features for muscle identification and joint function.
The Scapula: Introduction and Function
- The scapula, or shoulder blade, is a flat, irregular bone located on the posterior thorax.
- It plays a critical role in shoulder movement and serves as a site for muscle attachment.
Primary Bony Landmarks of the Scapula
- Medial (Vertebral) Border: Closest to the spinal column.
- Lateral (Axillary) Border: Closest to the armpit region.
- Superior Border: Top edge of the scapula.
- Subscapular Fossa: Anterior, concave surface facing the ribs, also called the costal surface.
- Spine of the Scapula: Prominent ridge on the posterior surface; serves as a muscle attachment site.
- Acromion: Highest point of the scapula; articulates with the clavicle at the acromioclavicular joint (AC joint).
- Supraspinous Fossa: Shallow depression above the spine on the posterior scapula.
- Infraspinous Fossa: Shallow depression below the spine on the posterior scapula.
- Glenoid Cavity (Fossa): Shallow socket on the lateral aspect for articulation with the head of the humerus (forms the shoulder joint).
- Supraglenoid Tubercle: Above the glenoid; attachment site for the long head of the biceps brachii.
- Infraglenoid Tubercle: Below the glenoid; attachment for the long head of the triceps brachii.
- Coracoid Process: Bony projection resembling a raven’s beak, important for muscle attachment.
- Suprascapular Notch: Indentation on the superior border; transmits the suprascapular nerve under the suprascapular ligament.
Importance of Scapular Anatomy
- Knowing bony landmarks helps identify where muscles attach and explains the origins of muscle names.
- Understanding scapular anatomy is essential for comprehending shoulder movement and diagnosing joint issues.
Key Terms & Definitions
- Fossa — A shallow depression on a bone.
- Process — A bony projection for muscle or ligament attachment.
- Tubercle — A small, rounded bony prominence.
- Acromion — The highest point, forming part of the shoulder.
- Glenoid Cavity — Shallow socket for head of humerus articulation.
- Coracoid Process — Projection resembling a crow’s beak; muscle attachment site.
- Spine of Scapula — Prominent ridge on posterior surface.
- Suprascapular Notch — Notch at the superior border for nerve passage.
Action Items / Next Steps
- Review all primary bony landmarks of the scapula.
- Practice identifying each landmark on an anatomical diagram or model.
- Memorize key terms and their definitions.