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 1^st 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 1^st 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 ® Horner’s syndrome.