Neck Flashcards
What muscle is the landmark for dividing regions of the neck?
What regions is the neck divided?
Sternomastoid (attaches from mastoid process to clavicle) & important for rotation & lateral flexion of neck
Posterior to the sternomastoid is posterior triangle & vertebral region
Sternomastoid region forms the root of the neck
In front of the muscle is the anterior triangle
Describe the layers & components of the superficial fascia
Superficial fascia external layer containing the skin, sub-cutaneous tissue, fat & cutaneous/superficial neurovascular supply
Also contains plasma muscle which blends with the muscles of facial expression
Superficial veins = external jugular and anterior jugular
EJV begins at the angle of the mandible and descents on sternomastoid
AJV descend in the midline (x2)
Describe the layers & components of the deep fascia
4 layers
Investing layer - outer layer that invests the neck, splitting to surround trapezius (posteriorly) and sternomastoid (anteriorly)
Prevertebral layer - invests muscles surrounding vertebral column - extensors of the neck that support the cervical lordosis and head
Pretracheal layer - invests the thyroid and sits anterior to the trachea
Carotid sheet - 2 laterally which invest the common carotid artery, vagus nerve and internal jugular vein
Thin and expansile to accomodate vein. Veins lateral to arteries
What are the features of the cervical spine?
C1-C7
Form a lordosis to support the head upright - reinforced by strong muscles
What are the clinical implications of the fascia?
Allows tracking of infective material and blood along length of the fascia to other structures
Spaces between the facial cylinders communicate with the mediastinum also, can spread infection to the thorax
What are the typical cervical vertebrae and what are there features?
C3 - C6
Hollowed out vertebral bodies - uncinate processes
Lateral masses with anterior & posterior tubercles, joined by a thin bar of bone that creates a transverse foramin
Transverse foramen allows passage of vertebral artery
Bifurcate spinous proces to allow attachment of many muscles
What are the atypical cervical vertebrae and their features?
C1, C2 (atlas & axis) and C7
C7 has a long spinous process
Atlas (C1) - no body, longest transverse process, facet for dens and anterior & posterior arches
ALLOWS FREE MOVEMENT OF HEAD ON C2
Axis (C2) - Dens (developmental body of C1), facets for articulation with arch of atlas
Strong spinous process
What are the posterior/lateral muscles of the neck?
Which in particular is an important landmark in the neck and for what structures?
Scalenous muscles
Anterior - medius - posterior
Attach from anterior & posterior tubercles of cervical spine & insert onto ribs
Located in the PREVERTEBRAL FASCIA
Scalenus anterior important landmark
Phrenic nerve sits and descends on it
Between scalenous anterior and medius the SUBCLAVIAN ARTERY & BRACHIAL PLEXUS are located
What are important cervical vertebrae landmarks for the carotid artery & vertebral artery?
Anterior tubercle (carotid tubercle) @ C6 - common carotid can compress against this
Bifurcation of common carotid @ C4
Vertebral artery in transverse foramina associated with C1 - C6
Which divisions of the common carotid branch within the region of the neck?
What are the branches?
The internal carotid artery is more posteriorly located and DOESN”T branch within the neck
External carotid artery more anterior and DOES branch within the neck
Anterior branches = facial, lingual and superior thyroid artery
Posterior = posterior auricular, occipital arteries
Features of the cervical IV discs
Largest discs relative to the size of body
Sit within the uncinate process of the body & are protected
Prevent forward slip and rotation
What are the 3 compartments of the neck?
Vertebral - posterior compartment - contains back/posture musculature & vertebrae
Visceral compartment - anterior to vertebral column and is related to the trachea & oesophagus. Contains the thymus, parathyroid glands
Vascular compartment - 2 laterally which comprise the carotid sheath
What is a clinically relevant feature of the pretrachial fascia?
Connects to the hyoid bone, therefore moves up and down with swallowing
Invests the thyroid gland so if lump which moves with swallowing know it is on the thyroid gland
What are the anterior muscles of the neck?
Anterior muscles = suprahyoid & infrahyoid (strap) muscles
Suprahyoid attach to the skull & hyoid bone to elevate the hyoid bone and larynx
Infrahyoid attach to the hyoid bone and to sternum, clavicle or scapula to depress the hyoid and larynx
Which cranial nerves are associated with the neck?
CN 9, 10, 11
CN 9 projects antero-inferior to oral cavity
CN 10 descends in the carotid sheath (lateral)
CN 11 descends posteriorly, going through sternomastoid