Human Anatomy Vol 1

(mdmrcog) #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


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.


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).


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).

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
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
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
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.

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

Oblique ridge


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