• HUMERUS
  • Head
  • Anatomical neck
  • Surgical neck
  • Greater tubercle
  • Lesser tubecle
  • Intertubercular sulcus; bicipital groove
  • Crest of greater tubercle; lateral lip
  • Crest of lesser tubercle; medial lip
  • Shaft of humerus; body of humerus
    • Anteromedial surface
    • Anterolateral surface
    • Posterior surface
      • Radial groove; groove for radial nerve
    • Medial border
      • Medial supraepicondylar ridge; medial supracondylar ridge
      • (Supracondylar process)
    • Lateral margin
      • Lateral supraepicondylar ridge; lateral supracondylar ridge
    • Deltoid tuberosity
  • Condyle of humerus
    • Capitulum
    • Trochlea
    • Olecranon fossa
    • Coronoid fossa
    • Radial fossa
  • Medial epicondyle
    • Groove for ulnar nerve
  • Lateral epicondyle

Humerus (statue- satyr) is the statue of the arm zone which is a part of upper limb zone.

Upper end of the statue

• Head of humerus (Neck of satyr/goat): imagine a statue in which the head of the goat statue is the scapula and from the neck region to the legs , the rest of the body is humerus.To study the body of the goat the head has to be separated so it leaves a closed end at the front of neck.
• Orientation of the neck of goat statue : it is directed medially and backwards and upwards . Imagine this as a bent neck. This neck along with the head forms the shoulder joint.
• Imagine a statue with both the hands amputated and shoulders looking like boulders closed. Between the two shoulders is the depression which we call the (intertubercular sulcus).
• So this statue does not have arms so it's whole body appears like a rod so there are two necks one is above shoulders and the other one is below shoulders.

• Anatomical neck - the uppermost neck above the shoulders
• Surgical neck - it is the neck present just below the shoulders where a ring road is present and a message wire called axillary nerve is present which supplies a rubber band called deltoid .
• Morphological neck - situated 0.5 cm above the surgical neck crossing the shoulders which determines the epiphyseal plates of hyaline cartilage.

Shaft (body of the satyr / goat statue)

Borders

• Backbone coming from between shoulders - anterior border
• Medial flank line - medial border
• Lateral flank line - lateral border

The backbone continues down as the anterior border and ends by separating two pits called as pillar pit and screw pit .

In the lower end the medial flank line starts from the leg and continues upwards to join the medial shoulder on the lateral side or the medial lip of intertubercular sulcus .

In the lower end lateral flank line is present but as it goes upwards it fades away along the line of spiral groove and then above it continues along greater tuberosity finally ending behind the lateral shoulder.

Surfaces

• Between back bone and medial flank line is the anteromedial surface
• Between backbone and lateral flank line is anterolateral surface. In the anterolateral surface deltoid tuberosity is present.
• Between medial flank line and lateral flank line is the posterior surface.

Lower end

Then there are rough areas

Deltoid tuberosity

Imagine a statue in a condition in which it's both legs are fused together with no gaps between them , even the ankles are fused but infront and behind the ankles there are spaces adjacent to the lateral leg is the pillar fossa , where as adjacent to the medial leg is the screw fossa

Medial shoulder - lesser tuberosity Lateral shoulder - greater tuberosity Medial leg - medial epicondyle Lateral leg - lateral epicondyle

Structures passing between two shoulders …

1. Two shoulders are attached by a transverse humeral ligament . 2. Tendon of long head of biceps brachii 3. Pectoralis major inserts on lateral lip , teres major inserts lf medial lip , floor for the lattissimus dorsi muscle. 4. Ascending branch of anterior circumflex humeral artery 5.

Medial flank line there is a rough ridge , it receives insertion of coracobrachialis muscle ( beaked rubber )

Brachioradialis muscle origin = lower half of anteromedial surface + anterior border + lower half of anterolateral surface

Along the medial flank line medial intermuscular septum is present and which is pierced by screw artery entering the posterior compartment of statue

Medial flank line - lowermost part ( medial supracondylar ridge ) anteriorly to medial intermuscular septum provides attachment to pronator teres muscle.