ANATOMY
Medicine Made Simple
, DEEP NECK
Root of the Neck (Thoracic Outlet)
• Is bounded by the
1. T1 vertebra
2. 1st pair of ribs & costal cartilages
3. Manubrium of the sternum
• It’s the junction of structures and tissue spaces passing to and
from the neck thorax and upper limb. An arbitrary area above the apex of the lungs.
• Structures pass through it between the apices of the lungs.
• The key to the root of the neck is the Scalenus Anterior & its relations.
Scalenus Anterior
Origin – Anterior tubercles of the transverse processes of typical vertebrae (C3-C6)
Insertion – Scalene tubercle & adjacent ridge on 1st rib
Nerve supply – Anterior rami of C4-C6
Anterior relations
1) The Phrenic Nerve,
passes vertically down across the obliquity of the muscle. (plastered to the prevertebral fascia).
The nerve leaves the medial border of the muscle low down.
Crosses in front of the Subclavian Artery and its internal thoracic branch, behind the Subclavian Vein.
Lying on the supra pleural membrane it passes medial to the apex of the lung, in front of the Vagus Nerve,
to enter the superior mediastinum.
2) The Ascending Cervical Artery,
a branch of the inferior thyroid artery of the thyrocervical trunk, runs up medial to the phrenic nerve. (on
the prevertebral fascia)
3) Transverse Cervical & Suprascapular,
In front of the prevertebral fascia, these arteries lie between the scalenus anterior and the carotid sheath
(internal jugular vein).
4) The Vagus Nerve
(in the carotid sheath) passes down in front of the subclavian artery, on the right side giving off its
recurrent laryngeal branch. It hooks around the artery and passes upwards.
The vagus nerve inclines posteriorly and runs on the medial surface of the apex of the lung to enter the
superior mediastinum.
5) The Internal Jugular Vein
is surrounded by the inferior deep cervical lymph nodes.
6) The Subclavian Vein
lies in a groove on the 1st rib; in a lower level than the Scalenus Anterior.
It runs below the clavicle and subclavius and joins the internal jugular vein at the medial border of scalenus
anterior.
The thoracic duct (left) and the right lymphatic duct (right) enter the angle of confluence of the two veins.
Medial relations