Human Anatomy Vol 1

c. The anterior branch is accompanied by the posterior

circumflex humeral vessels. It winds round the

surgical neck of the humerus, deep to the deltoid,

reaching almost up to the anterior border of the

muscle. It supplies the deltoid and the skin over its

anteroinferior part.

d. The posterior branch supplies the teres minor and

the posterior part of the deltoid. The nerve to the

teres minor bears a pseudoganglion, i.e. fibrous

tissue and fat without any neurons (Fig. 6.6). The

posterior branch then pierces the deep fascia at the

lower part of the posterior border of the deltoid and

continues as the upper lateral cutaneous nerve of the

arm.

Anostomoses oround ihe Body of the Scopulo

The anastomoses occurs in the three fossae, subscap-
ular, supraspinous and infraspinous. It is formed by:
a. The suprascapular artery, a branch of the
thyrocervical trunk (Fig. 6.13).
b. The deep branch of the transverse cervical attety,
another branch of the thyrocervical trunk.
c. The circumflex scapular artery, a branch of the
subscapular artery which arises from the third part
of the axillary artery.
Note that it is an the anastomoses between branches
of the first part of the subclavian artery and the branches
of the third part of the axillary artery.

SCAPULAB BEGION

Anostomoses over the Acromion Process

It is formed by:

a. The acromial branch of the thoracoacromial artery

(2nd part of axillary).

b. The acromial branch of the suprascapular artery (1st

part of subclavian).

c. The acromial branch of the posterior circumflex

humeral artery (3rd part of axillary).

Note that this is an anastomoses between the first

part of the subclavian artery and the branches of the

second and third parts of the axillary artery (Fig. 6.13).

The arterial anastomosesprovide a collateral circulation

through which blood can flow to the limb when the

distalpart of the subclavianartery,or the proximalpart

of the axillary artery is blocked (Fig. 6.13).

Mnemonics

Rotatory cuff muscles "SITS"

Supraspinatus

lnfraspinatus

Teres minor

Subscapularis

Suprascapular nerve and artery

Army (artery) goes over the bridge

Navy (nerve) goes under the bridge

Artery - suprascapular

Nerve- suprascapular

Bridge-superior transverse scapular ligament.

It

E

=o

CL

CL

f

co

.E

oo)

a

From thyrocervical

trunk of 1st part of

subclavian artery

Anastomoses between

suprascapular, deep branch

of transverse cervical and

circumfl ex scapular branches

Acromial process with

thoracoacromial artery from

2nd parl of axillary artery

Teres minor

Long head of

triceps brachii

Fig.6.13; Anastomoses around the scapula (dorsal aspect)