6.3 Prevertebral Region

Prevertebral Neck Muscles (25)

Weak flexors from front of vertebral column skull ¨ superior mediastinum

Covered by strong prevertebral fascia

Rectus capitis anterior

Front of foramen magnum ¨ lateral mass of atlas.

Rectus capitis lateralis

Edge to edge with anterior; jugular process of occipital bone ¨ transverse process of atlas

Anterior ramus of C1

Forwards lateral to atlanto-occipital jt ¨ supplies above 2 then ¨ into longus capitis overlying.

-           branch goes with XII ¨ meningeal branch, superior root of ansa cervicalis, branches to thyrohyoid and geniohyoid.

Longus Capitis

From basiocciput (in front of rectus capitis anterior) ¨ four tendons to C3-6 transverse processes

-           lies behind nasopharynx, bulging its wall slightly forward

Innervation: anterior rami C1-4;   Action: Flexes head

Longus Colli

Anterior tubercle of atlas ¨ superior mediastinum

-           triangular shape due to upper lower and central fibres converging together

-           picks up fibres from front of C2-7 and T1-3 and ant tubercles trans processes C3-6

Innervation: segmentally by anterior rami spinal nerves;  Action: flexes head.

Cervical Sympathetic Trunk

Ascends from thorax across neck of 1st rib (medial to highest intercostal vein) ¨ medial to vert a.

-           lies in front of prevertebral fascia, behind carotid sheath, medial to vagus

Ends at superior cervical ganglion: 3cm long in front of C2,3 vertebrae.

Middle cervical ganglion: small, inconsistent, medial to carotid tubercle of C6

-           in front of inferior thyroid artery

Inferior cervical ganglion: behind commencement of vertebral artery;

-           often fused with T1 ganglion ¨ stellate (cervicothoracic) ganglion in front of neck of 1st rib

-           connection to middle partly via ansa subclavia; passes in front of subclavian artery.

Distribution

No white rami from cervical nerves

Grey rami ¨ all 8 cervical nerves; superior ¨ C1-4, middle ¨ C5,6, inferior ¨ C7,8 (ie brach plexus)

Each ganglion also ¨ cardiac branch:

-           all pass to deep cardiac plexus apart from upper left ganglion ¨ superficial

-           all 6 pass behind CCA and subclavian to superior mediastinum.

Vascular branches follow arteries:

-           internal carotid nerve with ICA ¨ internal carotid plexus ¨ all branches + pterygopalatine ganglion + eyeball (latter including motor supply of dilator pupillae of iris).

-           Plexus on ECA ¨ all branches + pharyngeal plexus + submandibular + otic ganglia.

-           Middle cervical ganglion ¨ inferior thyroid artery

-           Inferior cervical ganglion ¨ branches to subclavian and to vertebral artery (vertebral plexus)

Interruption of cervical sympathetics ¨ HornerŐs syndrome.