Human Anatomy Vol 1

Groove for radial nerve

Deltoid tuberosity

Medial border Lateral border

Epiphyseal line of

medial epicondyle

Olecranon fossa

Fig.2.14: Features of right humerus seen from behind

Eorders

1 The upper one-third of the anterior border forms the
lateral lip of the intertubercular sulcus. In its middle
part, it forms the anterior margin of the deltoid
tuberosity. The lower half of the anterior border is
smooth and rounded.
2 The lnteral border is prominent only at the lower end
where it forms tlire lateral supracondylar ridge. Lr the
upper part, it is barely traceable up to the posterior
surface of the greater tubercle. In the middle part, it
is interrupted by the radial or spiral groozte (Fig. 2.13).
3 The upper part of the medial border forms the medial
lip of the intertubercular sulcus. About its middle it
presents a rough strip. It is continuous below with
the medial supracondylar ridge.

$urfsees

1 The anterolateral surfnce lies between the anterior and
lateral borders. The upper half of this surface is
covered by the deltoid. A little above the middle it is
marked by a V-shaped deltoid (Greek triangular
shaped) tuberosity. Behind the deltoid tuberosity the
radial groozse runs downwards and forwards across
the surface.
2 The anteromedial surface lies between the anterior and
medial borders. Its upper one-third is narrow and
forms the floor of the intertubercular sulcus. A
nutrient foramen is seen on this surface in its middle,
near the medial border (Fig. 2.13).

BONES OF UPPEB LIMB

3 The posterior surface lies between the medial and

lateral borders. Its upper part is marked by an

oblique ridge. The middle one-third is crossed by

t}ae radial grooae (Fig.2J.a).

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The lower end of the humerus forms the condyle which

is expanded from side to side, and has articular and

nonarticular parts. The articular part includes the

following.

L The capitulum (Latin little head) is a rounded

projection which articulates with the head of the

radius (Fig.2.13).

2 The trochlea (Greek pulley) is apulley-shaped surface.

It articulates with the trochlear notch of the ulna. The

medial edge of the trochlea projects doram 6 mm more

than the lateral edge: This results in the formation of

the carrying angle (Fig.2.1.3).

The nonarticular part includes the following.

1 The medial epicondyle is a prominent bony projection

on the medial side of the lower end. It is

subcutaneous and is easily felt on the medial side of

the elbow (Fig.2.73).

2 The lateral epicondyle is smaller than the medial

epicondyle. Its anterolateral part has a muscular

impression.

3 The sharp lateral margin just above the lower end is

called the lateral supracondylar ridge.

4 The medial supracondylar ridge is a similar ridge on

the medial side.

5 The coronoid fossa is a depression just above the

anterior aspect of the trochlea. It accommodates the

coronoid process of the ulna whenthe elbow is flexed

(Fig.2.13).

5 The radial fossa is a depression present just above the

anterior aspect of the capitulum. It accommodates

the head of the radius when the elbow is flexed.

7 The olecranon (Greek ulna head) fossa lies just above

the posterior aspect of the trochlea. It accommodates

the olecranon process of the ulna when the elbow is

extended (Fig.2.1.q.

ochm@nts

L The multipennate subscapularis is inserted into the

lesser tubercle (Fig. 2.15).

2 The supraspinatzs is inserted into the uppermost

impression on the greater tubercle.

3 The infraspinatzs is inserted into the middle

impression on the greater tubercle (Fig.2.1.6).

4 The teres minor is inserted into the lower impression

on the greater tubercle (Fig.2.76).

5 The pectoralis major is inserted into the lateral lip of

the intertubercular sulcus. The insertion is bilaminar

(Fig. 2.15).

Head covered with

articular cartilage

Capsular line

Surgical neck

Anatomical neck

Epiphyseal line

Morphological

neck

Oblique ridge

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