Diagram of the humerus

General
1

diagram of the humerus

2

Diagram of the Humerus

The humerus is the long bone in the upper arm that runs from the shoulder to the elbow. It is a crucial part of the skeletal system and plays a vital role in arm movement and function. Here, we will provide a detailed description and diagram of the humerus, explaining its anatomy and key features.

Anatomy of the Humerus

The humerus can be divided into three main parts: the proximal end, the shaft, and the distal end. Each part has distinct anatomical features.

  1. Proximal End:

    • Head: The rounded, ball-like structure that fits into the glenoid cavity of the scapula, forming the shoulder joint.
    • Anatomical Neck: A slight constriction immediately below the head.
    • Greater Tubercle: A large, prominent projection lateral to the head, providing attachment for the rotator cuff muscles.
    • Lesser Tubercle: A smaller projection on the anterior side, also serving as an attachment point for muscles.
    • Intertubercular Groove (Bicipital Groove): A groove between the greater and lesser tubercles that houses the tendon of the biceps brachii muscle.
    • Surgical Neck: A common fracture site, located just below the tubercles.

  2. Shaft:

    • Deltoid Tuberosity: A roughened area on the lateral surface of the shaft where the deltoid muscle attaches.
    • Radial Groove (Spiral Groove): A shallow groove running obliquely down the posterior aspect of the shaft, accommodating the radial nerve and deep brachial artery.

  3. Distal End:

    • Medial and Lateral Epicondyles: Bony projections on either side of the distal humerus, providing attachment points for forearm muscles.
    • Capitulum: A rounded knob on the lateral side that articulates with the head of the radius.
    • Trochlea: A spool-shaped structure on the medial side that articulates with the ulna.
    • Coronoid Fossa: A depression above the trochlea on the anterior surface, accommodating the coronoid process of the ulna during elbow flexion.
    • Olecranon Fossa: A large depression on the posterior surface, accommodating the olecranon process of the ulna during elbow extension.

Diagram of the Humerus

Below is a detailed diagram of the humerus, highlighting its major anatomical features:

Diagram of the Humerus

Key Features Labeled in the Diagram:

  1. Head: The top rounded part that fits into the shoulder socket.
  2. Anatomical Neck: Just below the head.
  3. Greater Tubercle: The larger bump on the outside.
  4. Lesser Tubercle: The smaller bump on the inside.
  5. Intertubercular Groove: The groove between the tubercles.
  6. Surgical Neck: Below the tubercles, common fracture site.
  7. Deltoid Tuberosity: The rough area where the deltoid muscle attaches.
  8. Radial Groove: The groove on the back of the shaft.
  9. Medial Epicondyle: The bump on the inner side of the elbow.
  10. Lateral Epicondyle: The bump on the outer side of the elbow.
  11. Capitulum: The outer knob that connects with the radius.
  12. Trochlea: The inner spool-shaped part that connects with the ulna.
  13. Coronoid Fossa: The front depression above the trochlea.
  14. Olecranon Fossa: The back depression above the trochlea.

Conclusion

Understanding the anatomy of the humerus is essential for students of medicine, physical therapy, and related fields. The humerus plays a critical role in the movement and functionality of the arm, and its detailed study helps in diagnosing and treating various injuries and conditions related to the upper limb.

For further detailed study, students are encouraged to refer to anatomical textbooks and resources that provide comprehensive information and illustrations of the humerus and its associated structures.