Exam 2: Unit V - Spinal Nerves; Intro and Cervical Plexus

How many pairs of spinal nerves are there?

31

Spinal Nerve Pairs

-8 cervical

-12 thoracic

-5 lumbar

-5 sacral

-1 coccygeal

Anterior (ventral or motor) Roots

carry efferent axons from cell bodies located in the anterior or lateral horns of gray matter

Posterior (dorsal or sensory) Roots

carry afferent axons from cell bodies located in the dorsal root ganglion

(TQ) Posterior roots separate into a number of rootlets that attach to the cord at the ______

posteriolateral sulcus

True or False? C1 and C2 ganglia are located on their respective vertebral arches

true

Sacral ganglia loated within the vertebral canal and coccygeal located inside the dura mater make up the _____

cauda equina

(TQ) The meningeal branch provides _____ and ______ fibers

somatosensory ; postganglionic sympathetic

The somatosensory and postganglionic fibers from the meningeal branch supply the _____, blood vessels, periosteum, ligaments, and IVDs in the anterior and lateral portions of the canal

dura

The mixed spinal nerve divides into what 2 primary rami?

-posterior (dorsal)

-anterior (ventral)

(TQ) Posterior primary ramus splits into lateral and medial branches EXCEPT for:

C1

Posterior primary ramus is smaller than the anterior ramus EXCEPT at:

C1, S4 and S5

Posterior primary ramus provides motor innervation to the _____ and sensory innervation to the skin on ______

deep back muscles ; either side of the spine

Anterior primary ramus provides motor innervation to the _____ and ____ trunk muscles and skeletal muscle in the ______

anterior ; lateral ; extremities

Anterior primary ramus provides sensory innervation to skin of _____ and anterior and lateral trunk

extremities

What are the 2 aspects of sympathetic chain communications?

1. white ramus communicans (WRC)

2. gray ramus communicans (GRC)

(TQ) The WRC carries myelinated axons form cell bodies found in the lateral horn cells at cord levels ______

T1-L2

Preganglion sympathetic fibers from the WRC enter the sympathetic chain and do what 2 things?

1. synapse in sympathetic chain ganglion

2. travel through sympathetic trunk —> splanchnic nerve

True or False? WRC is only associated with nerves T1-L2

true

GRC carries unmyelinated ______ axons from cell bodies in the sympathetic chain to the spinal nerve

postganglionic sympathetic

True or False? GRCs are located at every cord level

true

What are the cerviccal posterior rami?

-C1

-C2

-C3

-C4-C8

C1 is the ______ nerve

suboccipital

(TQ) C1 is motor supply only and does _______

NOT split

(TQ) C1 provides motor supply to:

-recctus capitis posterior major and minor

-obliquus capitis superior and inferior

-semispinalis capitis

(TQ) C2 medial branch is the ______ nerve

greater occipital

Medial branch of C2 provides sensory innervation to ______

posterior neck and scalp

Lateral branch of C2 provides motor supply to what muscles?

-semispinalis capitis

-longissimus capitis

-splenius capitis

(TQ) C3 medial branch is the _____ nerve

least occipital

Medial branch of C3 provides sensory innervation to ______

skin of posterior neck

Lateral branch of C3 provides motor supply to what muscles?

-semispinalis capitis

-longissimus capitis

-splenius capitis

(SAME AS C2)

C4-C8 medial branches provide sensory innervation to ____

skin of posterior neck

C4-C8 lateral branches provide motor supply to what muscles?

-iliocostalis cervicis

-longissimus cervicis

-longissimus capitis

Cervical plexus is formed by anterior (primary) rami of ______ spinal nerves

C1-C4

Fibers from the ______ communicate with the loop formed between C1 and C2

inferior vagal ganglion

Fibers from the spinal accessory nerve carry proprioceptive information and communicate with the loop formed by C2 and with _____

C3/C4

(TQ) C2 is with the ______ and C3/C4 are with _____

SCM ; trapezius

C1 fibers that supply the thyrohyoid and geniohyoid remain with the ______

hypoglossal

Fibers from C1 communicating with the hypoglossal nerve separate from the hypoglossal to form the _____ of the ansa cervicalis

superior root

GRC carry ______ fibers to the loop between C1 and C2 and roots of C3 and C4

postganglionic sympathetic

Superficial branches of the cervial plexus are ____ only

sensory

Superficial Branches of Cervical Plexus

-lesser occipital

-great auricular

-transverse cutaneous nerve of the neck

-medial/intermediate/lateral supraclavicular nerves

Lesser occipital nerve carries fibers from C2 to supply the skin on the superior 1/3 of the ____ as well as the skin behind the ear

auricle

(TQ) Lesser occipital nerve may be implicated in cases of ______

cervicogenic headache

Great auricular nerve carries fibers from ___ and ___

C2 ; C3

(TQ) Anterior branch of the great auricular nerve combines with the _____ to supply the skin over the parotid gland

facial nerve

(TQ) Posterior branch of the great auricular nerve supplies the skin over the ______

mastoid process

Transverse cutaneous nerve of the neck carries fibers from ____ and ____

C2 ; C3

Transverse cutaneous nerve of the neck divides into ascending and descending branches that supply the skin over the _____ muscle

platysma

Trunks from ___ and ____ combine to form a trunk that gives rise to the medial/intermediate/lateral supraclavicular nerves

C3 ; C4

(TQ) Medial supraclavicular nerve supplies the skin inferior to the sternal end of the _____ as far inferior as the _____

clavicle ; 2nd rib

(TQ) Intermediate supraclavicular nerve supplies the skin over the _____ and ____ muscles as far inferior as the 2nd rib

deltoid ; pectoralis major

(TQ) Lateral supraclavicular nerve supplies the skin over the _____ and _____ aspects of the shoulder

superior ; lateral

Deep branches of the cervical plexus are divided into a ____ and ____ series

medial ; lateral

The lateral series passes into the _____ triangle

posterior

Lateral Series Muscular Branches

C2: SCM

C3-C4: trapezius, levator scapulae, middle scalene

Medial series passes into the _____ triangle

anterior

(TQ) Medial Series Muscular Branches

-C1: rectus capitis lateralis

-C1/C2: rectus capitis anterior

-C1-C3: longus capitis

-C2-C4: longus coli

Branches from C2 and C3 combine to form the ____ of the ansa cervicalis

inferior root

(TQ) Ansa cervicalis supplies the ____, ____, and both bellies of the ____

sternohyoid ; sternothyroid ; omohyoid

Phrenic nerve is formed by fibers from C3-C5 with ____ contributing the most fibers

C4

The phrenic nerve receives _____ fibers from the cervical ganglia and supplies the diaphragm

postganglionic sympathetic