The Humerus

• Forensic Anthropology: A Comprehensive Introduction, p. 4333
• Imaging Anatomy: Bones, Joints, Vessels and Nerves, p. 2159

Proximal End

Fig. Proximal End of Right Humerus - anterior, lateral, and posterior views (Gray's Anatomy for Students)

Head

• Half-spherical; projects medially and slightly superiorly.
• Articulates with the glenoid cavity of the scapula at the glenohumeral (shoulder) joint.

Anatomical Neck

• Narrow constriction immediately distal to the head.
• Lies between the head and the tubercles laterally, and between the head and shaft medially.
• Fractures here are rare because the bone is thickest at this level.

Greater Tubercle (lateral)

Lesser Tubercle (anterior)

• Has a large smooth impression for subscapularis attachment.

Intertubercular Sulcus (Bicipital Groove)

• Deep groove separating the greater and lesser tubercles; continues inferiorly on the proximal shaft.
• Carries the tendon of the long head of biceps brachii.
• The lateral lip gives attachment to pectoralis major; the floor to latissimus dorsi; the medial lip to teres major.

Surgical Neck

• Horizontal constriction between the expanded proximal end and the narrower shaft.
• The axillary nerve and posterior circumflex humeral artery pass immediately posterior to it.
• The most common fracture site in the proximal humerus. Axillary nerve injury can occur.
• Gray's Anatomy for Students, p. 823

Shaft

• Cylindrical proximally, flattening distally.
• Deltoid tuberosity: V-shaped roughening on the lateral surface at the mid-shaft; the deltoid muscle inserts here.
• Coracobrachialis attachment: thin vertical roughening on the medial surface at a similar level.
• Posterior spiral groove (radial groove): runs obliquely from proximal-medial to distal-lateral on the posterior shaft. The radial nerve and profunda brachii artery lie in this groove. The radial nerve enters it ~20 cm proximal to the medial epicondyle (approximately 74% of the total humeral length).
  • Shaft fractures at this level commonly cause radial nerve palsy (wrist drop).
• Nutrient foramen: opens distally, toward the elbow ("away from the knee, toward the elbow").
• Miller's Review of Orthopaedics 9th Edition, p. 9682
• Rockwood and Green's Fractures in Adults 10th ed, p. 1873

Distal End

Fig. Osseous anatomy of the distal humerus/elbow joint - anterior and posterior views (Imaging Anatomy: Bones, Joints, Vessels and Nerves)

• Coronoid fossa (anterior): receives the coronoid process of the ulna during flexion.
• Radial fossa (anterolateral): accommodates the radial head during flexion.
• Olecranon fossa (posterior): receives the olecranon of the ulna during full extension. May be perforated, forming a septal aperture (normal variant - not to be confused with trauma).

• Imaging Anatomy: Bones, Joints, Vessels and Nerves, p. 3193
• Forensic Anthropology: A Comprehensive Introduction, p. 4342

Key Clinical Summary

Siding the Humerus (Forensic/Anatomical Note)

• The head is medial
• The olecranon fossa is posterior
• The deltoid tuberosity is lateral
• The nutrient foramen opens distally (toward the elbow)
• Forensic Anthropology: A Comprehensive Introduction, p. 4346

Swaras (स्वर)

The 7 Swaras - Saptaka (सप्तक)

In Carnatic music, Re is called Ri and the system of variants differs slightly from Hindustani.

Achal vs Vikrit Swaras

The 12 Swaras (Full Chromatic Scale)

• Komal (कोमल) = soft/flat (lowered by a semitone)
• Tivra (तीव्र) = sharp (raised by a semitone; only applies to Ma)
• Shuddha (शुद्ध) = pure/natural

Types of Swaras

1. Shuddha Swara - The pure, natural form of the note (e.g., Shuddha Re, Shuddha Ga)
2. Komal Swara - Flattened form; applies to Re, Ga, Dha, Ni
3. Tivra Swara - Sharpened form; applies only to Ma (Tivra Ma = F#)
4. Achal Swara - Fixed notes that never change: Sa and Pa

Animal/Bird Origins (Traditional Belief)

Swaras in Ragas

• Komal Ga and Komal Ni give a raga a melancholic, devotional quality (e.g., Raga Bhairavi)
• Tivra Ma gives a bright, mysterious quality (e.g., Raga Yaman)