prevertebral region

Prevertebral

Fascias
Deep

·      underlies subcutaneous fat

·      surrounds neck like collar

·      splits to enclose

·      sternomastoid

·      trapezius

·      meets ligamentum nuchae posteriorly

·      attached to hyoid bone

·      attached superiorly to

·      base of skull to tip of mastoid process

·      lower border of mandible

·      splits to enclose parotid between

·      attached inferiorly to

·      spine of scapula

·      clavicle

·      sternum

·      splits to enclose anterior jugular veins, omohyoid and subclavius

Pretracheal

·      covers trachea

·      lies deep to infrahyoid strap muscles

·      attached superiorly to hyoid

·      splits to enclose thyroid

·      fuses laterally with carotid sheath

·      blends inferiorly with adventitia of aortic arch

Carotid sheath

·      dense feltwork of areolar tissue

·      surrounds

·      common and internal carotid arteries

·      internal jugular vein

·      vagus nerve

·      attached to base of skull at margins of carotid canal

·      continued downwards along vessels to aortic arch

·      attached to deep surface of sternomastoid

·      here pretracheal fascia blends with it

Prevertebral

·      lies in front of prevertebral muscles

·      extends

·      from base of skull (in front of longus capitis and rectus capitis lateralis)

·      down to T3 (lower limit of longus colli)

·      out over scalenus anterior, medius and levator scapulae

·      deep to it are

·      cervical roots

·      3rd part of subclavian artery

·      superficial to it are

·      oesophagus and trachea

·      accessory nerve

·      subclavian vein

·      piercing it are cutaneous branches of cervical plexus

muscles
Recti

·      anterior ramus of C1 passes between and supplies them

Rectus capitis anterior

·      from lateral mass of atlas

·      to front of foramen magnum

Rectus capitis lateralis

·      from lateral mass of atlas

·      to jugular process of occipital bone

Longus capitis

Origin

·      anterior tubercles of C3-C6

·      via 4 tendons

Path

·      ribbon muscle passes upwards and medially

Insertion

·      basiocciput

Nerve supply

·      segmentally by anterior rami of C1-4

Longus colli

Upper fibres

·      from anterior tubercle of atlas

·      to anterior tubercles of C3-5

Lower fibres

·      from bodies of T1-3

·      to anterior tubercles of C5-6

Triangle

·      lateral border makes triangle with medial border of scalenius anterior

·      apex is Chassiagnac’s tubercle

·      base is 1st part of subclavian artery

·      contains

·      vertebral artery

·      cervical sympathetic trunk

·      stellate ganglion

Middle fibres

·      from bodies of C2-4

·      to anterior tubercles of C5-T3

Nerve supply

·      segmentally by anterior rami

Scalenes

·      see below

cervical sympathetic trunk

·      extends upwards

·      across neck of 1st rib (medial to supreme intercostal vein)

·      medial to vertebral artery

·      in front of pretracheal fascia

·      behind carotid sheath

·      to superior cervical gangilon

Ganglia

Superior cervical

·      large (3 cm long)

·      in front of lateral mass of atlas and axis

Middle cervical

·      small and inconstant

·      medial to carotid tubercle

Inferior cervical

·      usually fused to 1st thoracic (see below)

Stellate

·      cervicothoracic

·      fusion of inferior cervical and 1st thoracic

·      large (1 x 0.5 cm)

·      lies in front of neck of 1st rib

·      connected to middle cervical by ansa subclavia

·      passes in front of subclavian artery

Branches

Somatic

·      as grey rami to C1-C8

Visceral

·      to cardiac plexuses

Vascular

·      superior ganglion gives branch to internal carotid artery

·      called internal carotid nerve

·      supplies eyeball (Horner’s syndrome)

Root of neck

muscles
Scalenus anterior

Origin

·      anterior tubercles of C3-6

·      via 4 tendons

·      tendons end-to-end with longus capitis

Path

·      passes forwards and laterally

·      covered by prevertebral fascia

Insertion

·      1st rib

·      on scalene tubercle on inner border

Nerve supply

·      segmentally by anterior rami of C3-C8

Anterior relations

Deep to prevertebral fascia

·      phrenic nerve

·      plastered to front by prevertebral fascia

·      leaves medial border

·      passes between subclavian artery and vein

·      ascending cervical artery

·      branch of thyrocervical trunk

Superficial to prevertebral fascia

·      transverse cervical and suprascapular arteries

·      behind carotid sheath

·      vagus nerve

·      in carotid sheath

·      passes in front of subclavian artery

·      right gives off recurrent laryngeal branch which hooks around artery

·      internal jugular vein

·      subclavian vein

·      lies in groove on 1st rib

·      in front of (medial to) insertion of scalenius anterior

·      joins internal jugular vein at medial border of scalenius anterior

·      at angle of confluence is thoracic duct

Medial relations

Triangle

·      formed by

·      medial edge of scalenius anterior

·      lateral edge of longus colli

·      superior edge of subclavian artery and neck of 1st rib

·      apex is Chassaignac’s tubercle

·      crossed by common carotid artery

·      contains

·      stellate ganglion

·      vertebral artery and vein

·      crossed by

·      inferior thoracic artery

·      thoracic duct

Posterior relations

·      scalenius medius

·      separated from it by

·      2nd part of subclavian artery

·      anterior rami of C5-T1

·      T1 occupies subclavian groove on 1st rib

Lateral relations

·      emerging from lateral border

·      trunks of brachial plexus

·      3rd part of subclavian artery

·      lie behind prevertebral fascia

·      in front of prevertebral fascia

·      axillary and subclavian veins

Scalenius medius

Origin

·      posterior tubercles and intertubercular lamellae of C1-7

Insertion

·      1st rib

·      quadrangular area between neck and subclavian groove

Scalenius posterior

Origin

·      posterior tubercles of C3-7

Path

·      passes across outer border of 1st rib

Insertion

·      2nd rib

Subclavian artery

·      arises from

·      brachiocephalic trunk on right

·      directly from aortic arch on left

First part

·      part from origin to medial border of scalenius anterior

·      arches over suprapleural membrane

·      disappears behind scalenius anterior

Branches

Vertebral artery

·      arises at apex

·      enters triangular space

·      disappears at apex

·      enters foramen transversalis of C6

·      medial to it

·      superiorly is middle cervical ganglion

·      inferiorly is inferior cervical (or stellate) ganglion

·      connected by ansa subclavius in front of subclavian artery

Thyrocervical trunk

·      arises lateral to apex

·      divides into

·      transverse cervical

·      suprascapular

·      inferior thyroid

Internal thoracic artery

·      arise from lower surface

·      enters thorax

Second part

·      part behind scalenius anterior

Branches

Costocervical trunk

·      divides into

·      superior intercostal artery

·      deep cervical artery

Third part

·      part from lateral border of subclavius to outer border of 1st rib