self study: cervical plexus Flashcards
what is cervical plexus formed by?
anterior primary rami of C1-C4 nerves
where is the cervical plexus?
lies on surface of scalene (lateral neck) and levator scapulae muscles (superior scapula)
deep to IJV
within posterior triangle + prevertebral fascia
(muscular branches deep to sensory branches - think superficial cutaneous)
what do the sensory branches of cervical plexus supply?
skin of neck, part of scalp, ear
superior thorax
where do the sensory nerves enter the skin?
in the middle of posterior border of SCM at Erb’s point
cervical plexus block
what are the cutaneous branches of the cervical plexus?
greater auricular nerve (C2-C3) transverse cervical nerve (C2-C3) lesser occipital nerve (C2) supraclavicular nerves (C3-C4) (GaTcLcS)
what does the greater auricular nerve supply?
C2-C3
sensation to external ear + skin over parotid gland
(communicates with auricular branch of vagus + posterior auricular nerve (CN VII) - ear innervation)
what does transverse cervical nerve supply?
C2-C3
anterior neck
what does lesser occipital nerve supply?
C2
posterosuperior scalp
communicates with posterior branch of greater auricular nerve
what does supraclavicular nerve supply?
C3-C4
skin over supra-scapular fossa, upper thoracic region, sternoclavicular joint
what do the muscular branches of the cervical plexus form? supply?
loop = ansa cervicalis (C1-C3)
supplying most of the infrahyoid muscles (omohyoid, sternothyroid, sternohyoid)
(thyrohyoid supplied by hypoglossal)
action of ansa cervicalis innervation?
depress hyoid bone - for swallowing and speech
what is an important motor branch of cervical plexus?
phrenic nerve (C3+C4, some C5)
keeps the diaphragm alive
motor innervation to diaphragm
function of glenohyoid (suprahyoid) muscle?
moves hyoid bone anterior and upward, expanding airway (larynx) - phonation (?)
function of thyrohyoid (suprahyoid) muscle?
depress hyoid bone and elevates larynx (+ thyroid) - swallowing
