Anatomy of Head and Neck (GS) Quiz 2

anterior (ventral) root

motor/efferent fibers from cell bodies in the anterior horn

posterior (dorsal) root

sensory (afferent) fibers that convey neural impulses to the posterior horn

spinal nerve and rami

the anterior and posterior roots unite at the intervertebral foramen to form a spinal nerve

spinal nerves divide into

• posterior (dorsal) primary rami

• anterior (ventral) primary rami

where do the anterior and posterior roots unite?

intervertebral foramen

spinal nerves are… (sensory, motor, or mixed/both?)

mixed!

dorsal nerves go to…

the back

central nerves go to the…

cervical plexus

function of the posterior (dorsal) primary rami

innervate the deep muscles of the back and the skin of the posterior head, neck, and trunk

what makes up the anterior (ventral) primary rami

• cervical plexus C1-C4

• brachial plexus C5-T1

• thoracic spinal nerves T1-T12

• lumbar plexus T12-L4

• sacral plexus L4-S4

how many pairs of spinal nerves?

31

what is the cervical plexus formed by?

the ventral (anterior) rami of spinal nerves C1-C4

muscular branches of the cervical plexus

• longus capitis

• longus colli

• scalenes

• geniohyoid

• thyrohyoid

• ansa cervicalis

  • omohyoid, sternothyroid, sternohyoid

• phrenic nerve (C3, 4, 5)

function of muscular branches of cervical plexus

control neck muscles

phrenic nerve function

primary nerve for controlling diaphragm

C5 is part of…

• the brachial plexus

• branches from cervical plexus

• and its mixed!

the phrenic nerve travels to the…

• pericardium and the diaphragm via the anterior of the anterior scalene muscle

the phrenic nerves make their way…

across the anterior scalene, deep to the transverse cervical artery and suprascapular artery, travel down into the chest cavity to innervate the diaphragm

of a nerve is damaged above the diaphragm but below C5 will you still be able to breath?

yes! the phrenic nerve is C3-C5 and it innervates the diaphragm meaning breathing will be unaffected

ansa cervicalis superior root

C1 and C2

ansa cervicalis inferior root

C2 and C3

the shape of the ansa cervicalis is a…

loop!

cutaneous branches location

emerge around the middle of the posterior border of the SCM

Erb’s point

nerve point of the cutaneous branches of the cervical plexus

cutaneous branches of the cervical plexus

• lesser occipital nerve

• greater auricular nerve

• transverse cervical nerve

• supraclavicular nerves

lesser occipital nerve vertebrae

C2

great auricular nerve vertebrae

C2 and C3

transverse cervical nerve vertebrae

C2 and C3

Supraclavicular nerve vertebrae

C3 and C4

greater auricular goes to…

the ear

lesser occipital goes to…

occipital bone from posterior rami and ventral rami cervical plexus

transverse cervical goes to…

crosses the sternocleidomastoid

supraclavicular nerve is…

on top of the clavicle

brachial plexus is…

formed by the ventral (anterior) rami of the spinal nerve