Posterior Triangle of the Neck Flashcards
Palpable structures in the neck
hyoid bone
cricoid cartilage
thyroid cartilage
laryngeal prominence (Adam’s apple)
What attaches to lesser horn of hyoid bone?
Stylohyoid ligament.
Runs from the styloid process to the lesser horn of the hyoid bone.
C1-C7 pass ____ correspondingly numbered vertebrae
above
C8 passes ____ correspondingly numbered vertebrae
below
Atlanto-occipital joint
flexion/extension/lateral bending of skull on C1
Atlanto-axial joint
rotation w/ some flexion/extension, lateral bending of C1 on C2
alar ligaments
prevent excessive side-to-side motion of the skull on the cervical column
cruciate ligament components
- transverse ligament of the atlas
- superior longitudinal ligament
- inferior longitudinal ligament
posterior longitudinal ligament
prevents hyper flexion of cervical column
nuchal ligament
forms septum in posterior neck and prevents hyperflexion
anterior longitudinal ligament
prevents hyperextension of cervical column
Posterior atlanto-occipital membrane
Closes space between base of skull and C1.
Hangman’s fracture
bilateral fracture posterior arch of C2 w/ anterior subluxation of C2 on C3
(pars interarticularis fractures)
hyperextension/distraction injury
Clay shoveler’s fracture
tip of spinous process C6-T1 shears off
Jefferson fracture
compression fracture of C1 anterior and/or posterior arch
lateral masses split
transverse ligament tears
hyoid bone - which vertebral level?`
~C3
Contents of 2 lateral neuromuscular compartments of the neck (carotid sheath)
carotid a.
IJV
vagus n.
^within carotid sheath
Prevertebral fascia covers which m.?
surrounds all m. that attach to cervical vertebrae including…
scalenes
levator scapulae
suboccipital muscles
Fascial layers of the neck
investing fascia
alar fascia
pretracheal fascia
carotid sheath
Investing fascia covers which m.?
trapezius
sternocleidomastoids
mental process
2 halves of mandible joining
platysma m. nerve supply
cervical branch of facial nerve (CN VII)
trapezius m. nerve supply
spinal accessory n. (CN XI)
sternocleidomastoid m. nerve supply
spinal pt of accessory n. (motor) and ventral rami of C2-3 (proprioceptive)
contraction of one st sternocleidomastoid m. moves face to same/opposite side?
opposite
torticollis
“twisted neck” or “wry neck”
can be acquired or congenital (labor/positioning issues)
one SCM becomes shorter than opposite side
posterior triangle of neck boundaries
Posterior: anterior side of trapezius m.
Anterior: posterior side of SCM
Inferior: middle 1/3 of clavicle
Roof: skin, superficial fascia, platysma, investing layer of deep fascia
Floor: muscles covered by prevertebral fascia
Lesser Occipital n. (C2)
follows posterior border of SCM to innervate the scalp behind and above the ear
Great Auricular n. (C2,3)
crosses superficial to SCM
innervates the skin over the parotid gland, angle of the jaw and the posterior ear
Transverse Cervical Nerves (C2,3)
crosses SCM superficially
sensation for the skin of the front and side of the neck (anterior triangle)
Supraclavicular Nerves (C3,4)
medial, intermediate, and lateral branches
supply sensation over the shoulder (from the sternoclavicular joint to the acromion process), lateral neck and anterior upper thoracic wall.
cervical plexus
connections between ventral primary rami of C1-C4
great auricular n. (C2,C3)
lesser occipital n. (C2, C3)
transverse cervical n. (C2,C3)
supraclavicular n.s (C3,C4)
sensory nerves of the cervical plexus supply sensation to which area of the neck?
area of the neck below the mandible
Sensation from the posterior part of the neck and scalp is supplied by dorsal primary rami from
C2 – C4
CN XI path
emerges through jugular foramen to innervate SCM
then crosses posterior triangle to supply trapezius
divisions of Trigeminal CN V
ophthalmic n. (V1)
maxillary n. (V2)
mandibular n. (V3)
supply cutaneous sensation of head
posterior portion of scalp and neck is supplied by
dorsal rami of cervical spinal n. from C2-C4
scalene m. nerve supply
motor branches of cervical and brachial plexus
The middle and anterior scalene insert on ____, while the posterior scalene inserts on ____.
The middle and anterior scalene insert on rib 1, while the posterior scalene inserts on rib 2.
splenius captius nerve supply
dorsal rami of cervical n.
levator scapulae nerve supply
dorsal scapular n.
scalene compression syndrome
a type of Thoracic Outlet Syndrome
brachial plexus and subclavian artery can be compressed
sx: pain, muscle weakness, low BP in upper limb
Central line catheterization
entry to venous system via R subclavian v.
Inability to elevate shoulder on R. side –> possible damage to which n.?
spinal accessory (CN XI)
semispinalis capitus nerve supply
dorsal rami of cervical n.
suboccipital muscles
obliquius capitus (superior and inferior)
rectus captius posterior (minor and major)
- deepest group
- supplied by br. of dorsal primary rami of occipital n.
suboccipital n.
C1 dorsal ramus
supplies muscles of the suboccipital triangle
greater occipital n.
C2 dorsal ramus
supplies sensation around vertex of head
Angle of the mandible - which vertebral level?`
C2
Thyroid cartilage - which vertebral level?`
C4-C5
Cricoid cartilage - which vertebral level?`
C6
Atlanto-Axial instability
any issue w/ C1-C2
______ separates the anterior and middle scalenes
brachial plexus
Which vessel descends across the SCM and pierces the deep investing fascia?
external jugular v.
