Posterior triangle of the neck Flashcards
what are the attachments of platysma
from fascia above pectoralis major and clavicle to lateral neck and onto mandible
what is the innervation of platysma
facial nerve CN VII
what is the anterior border of the posterior triangle
posterior border of sternocleidomastoid
what is the base of the posterior triangle
clavicle
what is the posterior boundary of the posterior triangle
anterior border of trapezius
what are the contents of the posterior triangle
- external jugular vein
- roots of brachial plexus
- accessory nerve
- some sensory nerves of cervical plexus
- cervical and supraclavicular lymph nodes
describe the floor of the posterior triangle
muscular
what nerve passes from beneath SCM to ascend the neck towards the suboccipital region
lesser occipital
what is the path of the lesser occipital nerve
passes from beneath SCM to ascend the neck towards the suboccipital region
what nerves supply the skin on the lateral side of the neck and clavicle
supraclavicular nerves
what do the supraclavicular nerves supply
the skin on the lateral side of the neck and clavicle
what nerve passes from beneath SCM to cross anterior surface of this muscle
greater auricular nerve
what is the path of the greater auricular nerve
passes from beneath SCM to cross anterior surface of this muscle
what does the greater auricular nerve accompany
external jugular vein
what is the route of the lesser occipital nerve
C2
what is the route of the greater auricular nerve
C2 C3
what are the 3 supraclavicular nerves
lateral
intermediate and medial
what is the route of the lateral supraclavicular nerve
C3 4
what is the route of the intermediate supraclavicular nerve
C3 4
what is the route of the medial supraclavicular nerve
C3 4
what is the route of the transverse cervical nerve
C2 3
what nerve supplies cutaneous innervation to back of the head
greater occipital
what nerve supplies cutaneous innervation to back of the neck
posterior rami of C3-5
what nerve supplies cutaneous innervation to behind the ear
lesser occipital
what nerve supplies cutaneous innervation to lobe of ear and below ear
greater auricular
what nerve supplies cutaneous innervation to lateral neck and clavicle
supra-clavicular
what nerve supplies cutaneous innervation to anterolateral neck
transverse cutaneous nerves of neck (C2 3)
the external jugular vein is formed by the union of
posterior auricular vein and posterior division of the retromandibular vein
the external jugular vein crosses anterior surface of ___ to pass into the posterior triangle
crosses anterior surface of SCM to pass into the posterior triangle
the external jugular vein crosses the anterior surface of SCM to pass into the posterior triangle and cross ___ surface of ___ to reach the ___ vein deep in the root of the neck
cross anterior surface of posterior belly of omohyoid to reach the subclavian vein deep in the root of the neck
what is the route of the external jugular vein
crosses anterior surface of SCM to pass into the posterior triangle and cross anterior surface of posterior belly of omohyoid to reach the subclavian vein deep in the root of the neck
the internal jugular vein lies _____ to SCM in what triangle
posterior to SCM in anterior triangle
what vein may be in the midline or may be absent
anterior jugular midline
what nerve can be seen near the posterior boundary of the posterior triangle passing between SCM and trapezius
spinal accessory nerve CN XI
what does spinal accessory nerve supply
trapezius and sternocleidomastoid with motor innervation
where does the external jugular vein start and stop
angle of mandible to subclavian vein
what muscle is found crossing the posterior triangle deep
posterior belly of omohyoid
what small vessels cross the posterior triangle immediately posterior to omohyoid
transverse cervical and suprascapular vessels
what else is found deep in the posterior triangle
roots of the brachial plexus and phrenic nerve
what are the roots of the phrenic nerve
C3 4 5
the phrenic nerve crosses the anterior surface of what muscle
anterior scalene in the root of the neck
what are the roots of the brachial plexus
C5-T1
what is the path of the roots of the brachial plexus
arise from C5-T1 and cross through the posterior triangle to pass under the clavicle and into axilla
what triangle does SCM lie in
neither - forms boundary between
what are the attachments of SCM
mastoid process of temporal bone and superior nuchal line, clavicle and sternum (clavicular head and sternal head)
what gives motor innervation to SCM
spinal accessory nerve (CN XI)
what gives proprioceptive innervation to SCM
cervical plexus C2 C3
what structures cross SCM
external jugular vein and the greater auricular nerve
lateral flexion brings the head in what direction
closer to the shoulder
extension pulls the head in what direction
backwards
flexion brings the head in what direction
chin to chest
what movements can SCM create
- lateral flexion with rotation
- extension at atlanto-occipital joints
- flexion of cervical vertebrae
what are the 3 parts of trapezius
superior part - descending part
middle part - transverse part
inferior part - ascending part
what is the function of the descending (superior) part of trapezius
elevate scapular, rotate glenoid cavity
what is the function of the transverse part of the trapezius
retract scapula
what is the function of the ascending (inferior) part of trapezius
depress scapula
what is the motor innervation of trapezius
spinal accessory nerve (CN XI)
what is the proprioceptive innervation of trapezius
cervical plexus C3 C4
what is the function of trapezius
holds scapula in place - weightlifting
what are the attachments of trapezius
Superior nuchal line, nuchal ligament, spinous processes of C7-T12 to lateral third of clavicle, acromion and spine of scapula
the posterior belly of what muscle passes through the posterior triangle
omohyoid
what forms the floor of the posterior triangle of the neck
splenius capitis
levator scapulae
middle scalene
anterior scalene
what is the function of omohyoid
depress hyoid bone
what innervates the omohyoid bone
ansa cervicalis
what is the function of splenius capitis
extend and rotate neck
what is the inneration of splenius capitis
dorsal rami of middle cervical nerves
what are the attachments of levator scapulae
Transverse processes of atlas and axis, 3rd and 4th Cervical vertebrae to medial scapular border between superior angle and medial end of scapular spine
what is the function of levator scapulae
help control scapular position
elevate shoulder (with trapezius)
when shoulder is fixed levator scapulae can laterally flex the neck to the same side
when the shoulder is fixed what can levator scapulae do
laterally flex the neck to same side
what is the innervation of the levator scapulae
direct C3 4 5 via dorsal scapular nerve
what is the function of the scalene muscles
flex neck (bilateral)
tilt head to same side (unilateral)
elevate upper ribs
what are the attachments of the scalenes as a whole
transverse processes of cervical vertebra to ribs 1 and 2
what are the attachments of anterior scalene
transverse processes of C3-6 to scalene tubercle on rib 1
what are the attachments of middle scalene
transverse processes of C2-7 to rib 1 behind subclavian artery groove
what are the attachments of posterior scalene
transverse processes of C4-6 to rib 2
what is the innervation of anterior scalene
anterior rami C4-7
what is the innervation of middle scalene
anterior rami C3-7
what is the innervation of posterior scalene
anterior rami C5-7
where do the roots of the brachial plexus lie in the posterior triangle
between anterior and middle scalene
why is posterior scalene harder to see in dissection
partially obscured by middle scalene
what crosses anterior scalene
phrenic nerve