Human Anatomy Vol 1

BONES OF UPPER LIMB

Pectoralis minor

Conoid and trapezoid parts

of coracoclavicular ligament

Suprascapular notch and ligament

Omohyoid (inferior belly)

Coracobrachialis and

short head of biceps brachii

Coracoacromial ligament

Coracohumeral ligament

Biceps brachii, long head

Coracoacromial ligament

Capsule of acromioclavicular

joint

Glenoid cavity

Spinoglenoid notch

Deltoid

Superior angle

Supraspinatus

Trapezius Spine

Fig.2.10: Right scapula: Superior aspect

16 The inferior belly of the omohy oid arises from the upper
border near the suprascapular notch (Fig. 2.8).
17 The margin of the glenoid cavity gives attachment
to the capsule of the shoulder joint and to the
glenoidal labrum (Latin lip) (Fig.2.8).
f8fle margin of the facet on the medial aspect of the
-acromion gives attachment to the cnpsule of the
scromioclnoicular joint (Fig. 2.10).
19 The coracoacromial ligament is attached (a) to the
lateral border of the coracoid process, and (b) to the
medial side of the tip of the acromion process (Figs
2.10 and 6.7).
20 The coracohumeral ligament is attached to the root of
the coracoid process (Fig. 2.10).
21 The coracoclavicular ligament is attached to the
coracoid process: The trapezoid part on the superior
aspect, and the conoid part near the root (Fig. 2.10).
22 The transaerse ligament bridges across the
suprascapular notch and converts it into a foramen
which transmits the suprascapular nerve. The
suprascapular vessels lie above the ligament (Fig. 2.10).
23 The spinoglenoid ligament may bridge the
spinoglenoid notch. The suprascapular vessels and
nerve pass deep to it (Fig. 10.3).

The scapula ossifies from one primary centre and

seven secondary centres. The primary centre appears

near the glenoid cavity during the eighth week of

development. The first secondary centre appears in

the middle of the coracoid process during the first

year and fuses by the 15th year. The subcoracoid

centre appears in the root of the coracoid process

during the 10th year and fuses by the 16th to l8th

years (Fig. 2.11). The other centres, including two for

the acromion, one for the lower two-thirds of the

margin of the glenoid cavity, one for the medial

border and one for the inferior angle, appear at

puberty and fuse by the 25thyear.

The fact of practical importance is concerned with

the acromion. If the two centres appearing for

acromion fail to unite, it may be interpreted as a

fracture on radiological examination. In such cases,

a radiograph of the opposite acromion will mostly

reveal similar failure of union.

r Paralysis of the serrafus anterior causes 'winging'

of the scapula. The medial border of the bone

becomes unduly prominent, and the arm cannot

be abducted beyond 90 degrees (Fi9,2.12).

. The scaphoid scapula is a developmental anomaly,
in which the medial border is concave.

The humerus is the bone of the arm. It is the longest

bone of the upper limb. It has an upper end, a lower

end and a shaft (Figs 2.13 and2.1.4).

Side Determinotion

1 The upper end is rounded to form the head. The

lower end is expanded from side to side and flattened

from before backwards.

2 The head is directed medially, upwards and

backwards.

3 The lesser tubercle projects from the front of the

upper end and is limited laterally by the

intertubercular sulcus or bicipital groove.

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