Describe the arteries of the posterior triangle of the neck.
The arteries in the lateral cervical region are:
1.Cervicodorsal trunk (transverse cervical artery) 2.Suprascapular artery
3.Third part of the subclavian artery, and
4. Part of the occipital artery
The cervicodorsal trunk originates from the thyrocervical trunk, a branch of the subclavian artery, and divides into the superficial cervical and dorsal scapular arteries. The cervicodorsal trunk runs superficially and laterally across the phrenic nerve and anterior scalene muscle, 2 to 3 cm superior to the clavicle. It then crosses (passes through) the trunks of the brachial plexus, supplying branches to their vasa nervorum (blood vessels of nerves) and passing deep to the trapezius.
The superficial cervical artery accompanies CN XI along the anterior (deep) surface of the trapezius. The dorsal scapular artery runs anterior to the rhomboid muscles, accompanying the dorsal scapular nerve. The dorsal scapular artery may arise independently, directly from the subclavian artery.
The suprascapular artery, from the cervicodorsal trunk, a branch of the thyrocervical trunk, or from the subclavian artery, passes inferolaterally across the anterior scalene muscle and phrenic nerve. It crosses the subclavian artery (third part) and the cords of the brachial plexus. It then passes posterior to the clavicle to supply muscles on the posterior aspect of the scapula. The suprascapular artery may arise directly from the subclavian artery.
The occipital artery, a branch of the external carotid artery (Fig. 8.5A), crosses the lateral cervical region at its apex and ascends to supply the posterior half of the scalp.
The third part of the subclavian artery supplies blood to the upper limb. It begins approximately a finger's breadth superior to the clavicle, opposite the lateral border of the anterior scalene muscle. It lies posterosuperior to the subclavian vein in the inferior part of the lateral cervical region (Fig. 8.4E). The pulsations of the artery can be felt
on deep pressure in the omoclavicular triangle just superior to the clavicle (Fig. 8.3). The artery is in contact with the first rib as it passes posterior to the anterior scalene muscle; consequently, compression of the artery against this rib can control bleeding in the upper limb.