1: Posterior Cervical Triangle Flashcards
order of the deep fascia (outer to inner)
investing pretracheal buccopharyngeal alar prevertebral carotid sheath
investing fascia
surrounds traps, SCM, and infrahyoid mm.
pretracheal fascia
surrounds thyroid, trachea, esophagus, post. surface of infrahyoid mm.
buccopharygeal fascia
surrounds pharynx posteriorly
alar fascia
ant. layer of prevertebral fascia & runs behind buccopharyngeal fascia
prevertebral fascia (Danger Space)
surrounds prevertebral & deep back mm.
carotid sheath
column of fascia that surrounds the CCA, ICA, IJV, & Vagus n.
where is the carotid sheath
btwn SCM & prevertebral mm.
what is carotid sheath made of
condensations of deep cervical fascia
infections in carotid sheath
can spread from skull to middle mediastinum
where does the external carotid leave the sheath
at the bifurcation of the carotid a. the internal carotid stays inside
middle mediastinum
structures btwn the lobes of the lungs (other than the heart)
where does the CCA arise from
middle mediastinum
where is the pretracheal space
btwn trachea & infrahyoid mm., from thyroid cartilage down into anterior medistinum
where is the retropharyngeal space
btwn buccopharyngeal & alar fascia, from skull base down into superior mediastinum
where is the prevertebral “danger” space
btwn alar & prevertebral fascia
at T12 at posterior of thoracic cavity
infections in the danger space
can spread from skull base down into posterior mediastinum
notorious for inferior spread of infections here
zone I of neck
thoracic inlet to cricoid cartilage
zone II of neck
cricoid cartilage to angle of mandible
zone III of neck
angle of mandible to base of skull
PCT boundaries
anterior=SCM
posterior=trapezius m.
inferior=middle 1/3 of clavicle
PCT contents
platysma m. external jugular v. cutaneous nn. motor nn. transverse cervical a. suprascapular a. deep mm.
PCT cutaneous nn.
branches of our cervical plexus, all emerge deep to SCM at Erb’s point
lesser occipital (C2-C3) great auricular (C2-C3) transverse cervical (C2-C3) supraclavicular (C3-C4)
lesser occipital n.
(C2-C3)
runs sup. along post. border of SCM
crosses over portion of occipital a.
supplies skin of scalp at apex of triangle
great auricular n.
(C2-C3)
ascends vertically on surface of SCM
runs with EJV superiorly toward ear
supplies lobe & skin post. to auricle, and angle of mandible to mastoid process
transverse cervical n.
(C2-C3)
runs transversely across middle of SCM
supplies skin of ACT & lateral neck
supraclavicular nn.
(C3-C4)
3 main branches: medial, intermediate, lateral (post.) nn.
superficial to clavicle & deep to platysma
supply skin of clavicular region
PCT motor nn.
accessory n. (CN XI)
phrenic n. (C3-C5)
accessory n.
(CN XI)
emerges from jugular foramen
runs diagonally thru triangle, deep to investing fascia
supplied SCM & trapezius mm.
phrenic n.
(C3-C5)
descends vertically along anterior scalene m.
crossed anteriorly by transverse cervical a. & suprascapular a.
enters thorax btwn subclavian v. & a.
travels along pericardial sack to support diaphragm (both sensory and motor)
external jugular v.
drains into subclavian v.
transverse cervical a.
from thyrocervical trunk
suprascapular a.
from thyrocervical trunk
PCT deep mm.
splenius capitis m.
levator scapulae m.
3 scalene mm.
omohyoid m. (inf. belly)
splenius capitis m.
o: spinous processes of C7-T4 vertebrae
i: occipital bone & mastoid process of skull
a: extend & laterally rotate head & neck
inn: dorsal rami of spinal nn.
levator scapulae m.
o: transverse processes of C1-C4 vertebrae
i: superomedial border of scapula
a: elevate scapula
inn: dorsal scapular n. (C5)
anterior scalene m.
o: transverse processes of C3-C6
i: 1st rib
a: tilt neck laterally
inn: ventral rami C3-C8 nn.
use this to find phrenic n.
middle scalene m.
o: transverse processes of C2-C7
i: 1st rib
a: tilt neck laterally
inn: ventral rami C3-C8 nn.
subclavian a. is in btwn anterior & middle scalene mm.
posterior scalene m.
o: transverse processes of C4-C6
i: 2nd rib
a: tilt neck laterally
inn: ventral rami C3-C8 nn.
interscalene triangle
elongated triangle deep to PCT
formed by ant scalene, mid scalene & 1st rib
brachial plexus & subclavian a. pass thru it
subclavian v. passes anteriorly to ant. scalene m.
