VIDEO
CONTENT
QUIZ
MATERIALS
Quick Facts
Key Features
Ossification
Variations
Surface Anatomy
Clinical Correlates
Quick Facts about the Humerus
- Location: Arm
- Bone Type: Long bone
- Key Features: Head, anatomical neck, greater and lesser tubercles, body, and condyle
- Articulation Points: Scapula, radius, and ulna
- Arterial Supply: Brachial artery, anterior circumflex humeral artery, deep brachial artery
Key Features & Anatomical Relations of the Humerus
- General Structure: The humerus is the sole bone in the arm and the largest bone in the upper limb.
- Classification: It is a long bone.
- Parts: The bone includes the head, anatomical neck, greater and lesser tubercles, body, and condyle.
- Surfaces: Anterolateral, anteromedial, and posterior surfaces are present, along with anterior, medial, and lateral borders.
- Landmarks: Notable landmarks are the capitulum, trochlea, intertubercular sulcus, deltoid tuberosity, olecranon fossa, and coronoid fossa.
Location and Articulation
- Position: The humerus is found distal to the pectoral girdle and proximal to the radius and ulna.
- Joints: It forms the glenohumeral (shoulder) joint with the scapula, the humeroulnar joint with the ulna, and the humeroradial joint with the radius as part of the elbow joint.
Ossification of the Humerus
- Ossification Centers: The humerus develops from eight ossification centers:
- Body: Appears around the eighth week in utero.
- Head: Emerges before birth or within the first six months post-birth.
- Greater Tubercle: Appears within the first two years.
- Lesser Tubercle: Forms around the fifth year.
- Capitulum: Becomes visible within the first year.
- Trochlea: Appears between the ninth and tenth years.
- Medial Epicondyle: Develops during the fourth to sixth years.
- Lateral Epicondyle: Materializes during the twelfth year.
- Fusion: The ossification centers merge at different stages of adolescence and early adulthood, with full fusion by the age of twenty.
Variations in Humerus Anatomy
- Intertubercular Sulcus: This feature is usually more prominent in males.
- Uncommon Formations:
- A supracondylar process can appear on the anteromedial surface due to ossification of the ligament of Struthers.
- A supratrochlear foramen may exist above the capitulum and trochlea.
Surface Anatomy of the Humerus
- Palpation Points:
- Head: Detectable through deep palpation in the axillary fossa.
- Greater Tubercle: Felt beneath the deltoid muscle just below the acromion.
- Lesser Tubercle: Found beneath the deltoid muscle near the coracoid process.
- Medial and Lateral Epicondyles: These are subcutaneous and easily palpable.
Clinical Correlates
- Humerus fractures
- Glenohumeral joint dislocation
- Elbow joint dislocation