Exam 2: Unit V: Cervical Plexus Flashcards
What forms the cervical plexus?
anterior (primary) rami of C1-C4 spinal nerves
What do the nerve roots making up the cervical plexus form?
a series of communicating loops
What CN communicates with the loop formed by C1 and C2?
fibers from inferior (nodose) vagal ganglion
What CN communicates with the loop formed by C2 and C3, and with C3 and C4? What info does it carry?
spinal root of accessory nerve; carries proprioceptive info
How does the spinal root of the accessory nerve communicate with the cervical plexus?
carries proprioceptive info:
- from SCM to C2 and C3
- from trapezius to C3 and C4
How does the Hypoglossal nerve communicated with the cervical plexus?
communicates with C1 fibers
When the C1 fibers communicating with the Hypoglossal nerve separate from it, what do they become? What about the C1 fibers that stay with the hypoglossal nerve?
separate–> superior root of the ansa cervicalis
stay with –> supply thyrohyoid and geniohyoid
What CNs communicate with the cervical plexus?
(X, XI, XII)
- Vagus –inf. ganglion (C1 and C2)
- Accessory Nerve (C2/C3 and C3/C4)
- Hypoglossal nerve (C1)
What type of communicans from the superior cervical ganglion are ass. with the cervical plexus? What type of fibers does it carry? What part of the cervical plexus does it communicate with?
gray rami communicans carrying postganglionic sympathetic fibers
loop b/w C1 and C2 and roots of C3 and C4
What are the 6 superficial branches of the cervical plexus?
- Lesser Occipital Nerve (C2, ~C3)
- Great auricular Nerve (C2, C3)
- Transverse Cutaneous nerve of the neck (C2, C3)
Trunks of C3 and C4 combine and form: - Medial Supraclavicular nerve (C3,C4)
- Intermediate supraclavicular nerve (C3,C4)
- Lateral supraclavicular nerve (C3,C4)
What does the cervical plexus all communicate with?
- CN X, XI, XII
- Sympathetic trunk (Superior Cervical Ganglion) –> Gray communicans
What nerve may be implicated in cases of cervicogenic headaches?
Lesser occipital nerve
What cervical fibers does the lesser occipital nerve carry?
C2 (sometimes C3)
What nerve supplies the skin on the superior 1/3 of the auricle as well as the skin behind the ear?
lesser occipital nerve
What two other nerves does the lesser occipital nerve have communications with?
greater occipital nerve and great auricular nerve
What cervical fibers does the Great auricular nerve carry?
C 2 and C3
What nerve enters the parotid gland? What occurs when this nerve does?
Great auricular nerve; divides into anterior and posterior branches
What does the Anterior branch of the Great auricular nerve combine with? What does it supply?
the facial nerve to supply skin over the parotid gland
What does the Posterior branch of the Great Auricular nerve supply?
skin over mastoid process
What cervical fibers does the Transverse cutanesous nerve of the neck carry?
C2 and C3
What does the Transverse Cutanesous nerve of the neck divide into? What does it supply?
ascending and descending branches
- both supply skin over platysma muscle
What cervical trunks combine to form the supraclavicular nerve?
C3 and C4
The Trunks of C3 and C4 combine to form a trunk that gives rise to what three nerves?
- Medial supraclavicular nerve
- Intermediate supraclavicular nerve
- lateral supraclavicular nerve
What does the medial supraclavicular nerve supply?
skin inf. to sternal end of the clavicle, as far inf. as 2nd rib
What does the intermediate supraclavicular nerve supply?
skin over deltoid and pectoralis major, as far inf. as 2nd rib
What does the lateral supraclavicular nerve supply?
skin over superior and lateral aspect of shoulder
What do the Deep branches of the cervical plexus divide into?
a medial series and a lateral series
What series of the deep branches of the cervical plexus passes into the posterior triangle?
lateral series
What series of the deep branches of the cervical plexus passes into the anterior triangle?
the medial series
What are the branches of the lateral series of the deep branches of the cervical plexus?
- Spinal Accessory Nerve–> may receive communicating branches carrying fibers of C2-4
- Muscular Branches ass. w/ 4 muscles
What are the four muscular branches of the lateral series of the deep branches of the cervical plexus? And what cervical levels are ass.?
- SCM (proprioception from C2)
- Trapezius (proprioception from C3,C4)
- Levator scapula (C3.C4 motor and sensory)
- Middle scalene (fibers from C3,C4)
What are the three communicating branches ass. with the Medial series of the deep branches of the cervical plexus?
- b/w vagus and loop C1 and C2
- 3-4 gray rami communicans from Superior Cervical Ganglion to upper 4 cervical nerves
- Fibers from C1 communicating with hypoglossal nerve–> then separating from it to form superior root of ansa cervicalis
What are the four muscles that the medial series of the deep branches the cervical plexus send fibers to? What cervical levels are ass. with each?
- Rectus capitis laterali (C1)
- Rectus capitis anterior (C1,C2)
- Longus capitis (C1-C3)
- Longus colli (C2-C4)
What branches of the cervical plexus combine to form the inferior root of the ansa cervicalis?
branches form C2 and C3
recall the superior root has only C1 fibers
What muscles does the ansa cervicalis supply?
- sternohyoid
- sternothryroid
- omohyoid
What fibers form the Phrenic Nerve? Which one contributes the most?
C3,C4,C5
C4 contributes the most
How does the Phrenic nerve descend through the neck?
anterior to the anterior scalene muscle
Where does the Phrenic nerve receive other fibers from? (besides C3,C4,C5)
postganglionic sympathetic fibers from the cervical ganglion
What does the Phrenic Nerve supply?
the diaphragm
What could a subluxation at C3,C4,C5 cause, in relation to the phrenic nerve?
Hiccups
Spinal cord injuries would have to occur above what level to take out the diaphragm?
C5
Elaborate on why we it is interesting how we don’t have innervation to the diaphragm be at the level of the diaphragm, around T11-T12.
If nerve supply for the diaphragm was around T11-T12, then a spinal cord injury to like T6 would take out your breathing
