Quiz 4: Cervical Plexus Flashcards
The cervical plexus is formed by the anterior primary rami of ____ through ____ spinal nerves.
C1, C4
T/F: The nerve roots of the cervical plexus form a series of communicating loops.
True
Fibers from what communicate with the loop formed by C1 and C2?
Inferior Vagal Ganglion
Fibers from the spinal accessory nerve carry ____________ information.
Proprioceptive
Fibers from the spinal accessory nerve communicate with the loop formed by what?
C2 & C3 with C3 & C4
Fibers from sternocleidomastoid travel to _____.
C2
Fibers from Trapezius travel to ______.
C3 & C4.
The hypoglossal nerve communicates with C1 fibers that will later separate from the hypoglossal nerve to become what?
Superior root of the ansa cervicalis
C1 fibers from the hypoglossal nerve supply what muscles?
Thyrohyoid & Geniohyoid
Usually three gray rami communicans carry ___________ __________ fibers to the loop between C1 & C2 and roots of C3 & C4.
Postganglionic sympathetic
What type of postganglionic sympathetic fibers, specifically, are carried in the gray rami communicans?
Vasomotor, Sudomotor and Pilomotor
What does vasomotor supply?
Muscular lining in blood vessels
What does sudomotor supply?
Sweat glands
What does pilomotor supply?
Hair follicles
What does the lesser occipital nerve supply?
- Skin on superior 1/3 of auricle
- Skin behind the ear
The Lesser Occipital Nerve carries fibers from what level(s)?
C2 (and occasionally C3)
Why is the lesser occipital nerve clinically significant?
May be implicated in cases of cervicogenic headache. Adjusting C1/C2 and occiput can help.
The Great Auricular Nerve carries fibers from what level?
C2 & C3
Where does the Great Auricular Nerve enter?
The parotid gland
What does the Great Auricular Nerve divide into?
Anterior and Posterior Branches
The anterior branch of the Great Auricular Nerve combines with what nerve?
Facial Nerve VII
What does the anterior branch of the Great Auricular Nerve (& CN VII) supply?
The skin over the parotid gland
What does the posterior branch of the Great Auricular Nerve supply?
Skin over the mastoid process.
Where does the Transverse Cutaneous Nerve of the neck carry fibers from?
C2 & C3
What two branches does the Transverse Cutaneous Nerve of the neck divide into?
- Ascending branch
- Descending branch
What do the ascending and descending branches of the Transverse Cutaneous Nerve of the neck supply?
Skin over the platysma muscle
The trunks from C3 & C4 combine to form a trunk that gives rise to what?
Medial, Intermediate and Lateral Supraclavicular Nerves
What does the Medial Supraclavicular Nerve supply?
Skin inferior to the sternal end of the clavicle, as far inferior as the second rib.
What does the Intermediate Supraclavicular Nerve supply?
Skin over the deltoid and pectoralis major, as far inferior as the second rib.
What does the Lateral Supraclavicular Nerve supply?
Skin over the superior and lateral aspects of the shoulder.
Deep branches of the cervical plexus are divided into what?
Medial and Lateral Series
The Lateral series of the deep branches passes into what?
Posterior Triangle
T/F: The lateral series of the deep branches consists of sensory branches and communicating branches.
False, consist of communicating branches and muscular branches.
The spinal accessory nerve may receive communicating branches carrying fibers from where?
C2-C4
T/F: Muscular branches are associated with four muscles.
True
What muscles are the muscular branches associated with?
- Sternocleidomastoid
- Trapezius
- Levator Scapula
- Middle Scalene
SCM receives what type of fibers?
Proprioception
Where does SCM receive proprioceptive fibers from?
C2, (maybe C3)
Trapezius receives what type of fibers?
Proprioception
Where does Trapezius receive proprioceptive fibers from?
C3, C4, (possibly C2)
Levator Scapula receives what type of fibers?
Motor and Sensory
What is Levator Scapula innervated by?
C3 & C4
Where does Middle Scalene receive fibers from?
C3 & C4
The medial series of the deep branches passes into where?
Anterior Triangle
T/F: The medial series of the deep branches consists of muscular branches and communicating branches.
True
Describe the first communicating branch of the medial series of the deep branches?
Between vagus and loop between C1 and C2
Describe the second communicating branch of the medial series of the deep branches?
3 or 4 gray rami communicans from the superior cervical ganglion to the upper four cervical nerves
Describe the third communicating branch of the medial series of the deep branches?
Fibers from C1 communicating with the hypoglossal nerve, then separating from the hypoglossal to form the superior root of the ansa cervicalis
Where are muscular branches sent to in the medial series of the deep branches?
- Rectus Capitis Lateralis, C1
- Rectus Capitis Anterior, C1, C2
- Longus Capitis, C1-C3
- Longus Colli, C2-C4
What root level(s) is/are associated with Rectus Capitis Lateralis?
C1
What root level(s) is/are associated with Rectus Capitis Anterior?
C1, C2
What root level(s) is/are associated with Longus Capitis?
C1-C3
What root level(s) is/are associated with Longus Colli?
C2-C4
Branches from C2 and C3 combine to form what?
Inferior Root of the Ansa Cervicalis
What does the Ansa Cervicalis supply?
- Sternohyoid
- Sternothyroid
- Both bellies of Omohyoid
The Phrenic Nerve is formed by which fiber levels?
C3, C4 & C5
Which level contributes the most fibers to the phrenic nerve?
C4
Where does the phrenic nerve run?
Descends through the neck, anterior to the anterior scalene muscle.
What type of fibers are received by the phrenic nerve via the Cervical Ganglia?
Postganglionic Sympathetic Fibers
What is the nerve supply to the diaphragm?
Phrenic Nerve
What nerve is involved with the onset of hiccups?
Phrenic Nerve
What is one suspected cause of hiccups related to chiropractic?
Subluxation
Why is the phrenic nerve really unique evolutionarily?
It’s initial location is very high up from it’s innervation.
**This is important because the life of a person who has a severed spinal cord is likely to be spared because breathing isn’t inhibited (due to diaphragm function still being intact).
