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AAAC63 21/5/05 11:02 AM Page 140
63 The root of the neck

Middle cervical ganglion
Scalenus medius
Vertebral artery
Scalenus anterior Sympathetic trunk
Phrenic nerve Inferior thyroid artery
Upper trunk of brachial plexus
Superficial cervical artery
Vagus
Suprascapular artery, nerve
Subclavian artery
Dorsal scapular artery
Subclavian vein
Carotid sheath
Internal thoracic artery Inferior cervical ganglion

Thoracic duct
Fig.63.1
The deep structures at the root of the neck and in the thoracic outlet.
The curved arrow on the right side of the diagram indicates the course of the thoracic duct

Sympathetic trunk
Scalenus posterior
Superior intercostal artery
Attachment of scalenus medius
1st thoracic nerve
Serratus anterior
8th cervical nerve
(first digitation)
Lower trunk of brachial plexus Scalene tubercle,
Subclavian artery for attachment of
Subclavian vein scalenus anterior

Subclavius
Costoclavicular ligament
Fig.63.2
The structures related to the upper surface of the first rib

The area defined by the first thoracic vertebra, the first ribs and the • Scalenus medius: is behind scalenus anterior and is inserted by mus-
manubrium sterni is called the thoracic inlet (or outlet) (Fig. 63.1). cular fibres into a large area of the 1st rib. The subclavian artery and the
Through this relatively confined space pass the trachea and oesopha- trunks of the brachial plexus are between the two muscles and the sub-
gus, the carotid and subclavian arteries and the corresponding large clavian vein is in front of scalenus anterior. The gap between the two
veins as well as the apices of the lungs and important nerves. muscles may be narrow and the tough tendon of scalenus anterior may
compress the lower trunk of the brachial plexus and/or the subclavian
The scalene muscles artery, giving rise to one form of the thoracic outlet syndrome (see also
• Scalenus anterior: passes down from the transverse processes of cervical rib, p. 7).
some of the cervical vertebrae and is inserted by means of a narrow ten-
don into the scalene tubercle on the medial border of the 1st rib.

140 Head and neck