The Cervical Plexus

Question 1

What 3 nervous system structures arise from the C1 spinal nerve?

Answer 1

1. (peripheral nerve) suboccipital nerve - dorsal ramus of C1 spinal nerve
2. ventral ramus of C1 spinal nerve
3. superior root of the ansa cervicalis —> superior omohyoid branch

** inferior root of ansa cervicalis (arising from spinal nerve C2-3) innervates inferior belly of the omohyoid, sternothyroid, and sternohyoid

Question 2

What muscular branches arise from cervical ventral rami?

Answer 2

1. nerve to geniohyoid muscle (C1)
2. nerve to thyrohyoid muscle (C1)
3. superior root of the ansa cervicalis (C1) - superior belly of the omohyoid muscle
4. inferior root of the ansa cervicalis (C1) - sternohyoid, sternothyroid, and inferior belly of the omohyoid muscles
5. phrenic nerve- to the diaphragm
6. MISC- longus capitis, longus coli, anterior, middle, and posterior scalene muscles

Question 3

What muscular branches arise from the cervical dorsal rami?

Answer 3

• suboccipital nerve- semispinalis capitis, inferior oblique, superior oblique, rectus capitis posterior major and rectus capitis posterior minor muscles
• Lateral branch of C2 spinal nerve - splenius capitis, longissimus capitis, semispinalis capitis
• Lateral branch of C3- overlying neck muscles
• Lateral branches of C4-8- overlying neck muscles

Question 4

What primarily sensory branches arise from the cervical dorsal rami?

Answer 4

C2 medial branch- greater occipital nerve

C3 medial branch- 3rd occipital nerve

C4-8 medial branches- sensory and postganglionic sympathetic (gray rami communicans) innervation of the skin overlying the cervical vertebrae to the articular facet joints

Question 5

Function of the suboccipital nerve:

Answer 5

sensory, postganglionic sympathetic [gray ramus] and motor innervation of:

semispinalis capitis

(SUBOCCIPITAL MUSCLES) inferior oblique, superior oblique, rectus capitis posterior major and rectus capitis posterior minor muscles

Question 6

Function of C2 medial branch - greater occipital nerve:

Answer 6

sensory and postganglionic sympathetic [gray ramus] innervation of the skin overlying the back of the head

Question 7

Function of C2 lateral branch:

Answer 7

sensory, postganglionic sympathetic [gray ramus] and motor innervation of the splenius capitis, longissimus capitis & semispinalis capitis muscles

Question 8

Function of the C3 medial branch- 3rd occipital nerve:

Answer 8

sensory and postganglionic sympathetic [gray ramus] innervation of the skin overlying the suboccipital triangle

Question 9

Function of lateral branch of C3 spinal nerve:

Answer 9

sensory, postganglionic sympathetic [gray ramus] and motor innervation of the overlying neck muscles

** same function of lateral branches of C4-8 spinal nerves

Question 10

Function of the medial branches of C4-8 spinal nerves:

Answer 10

sensory and postganglionic sympathetic (gray rami communicans) innervation of the skin overlying the cervical vertebrae and to the articular facet joints

Question 11

Function of the lateral branches of C4-8

Answer 11

sensory, postganglionic sympathetic (gray ramus) and motor innervation of the overlying neck muscles

** same as lateral branch of C3 spinal nerve

Question 12

What sensory (cutaneous and non-cutaneous) branches arise from the cervical ventral rami?

Answer 12

CUTANEOUS

1. lesser occipital nerve (C2)
2. greater auricular nerve (C2,3)
3. transverse cervical n. (C2, 3)
4. supraclavicular n. (C3, 4)

NON-CUTANEOUS

1. proprioceptive branches to trapezius muscle
2. proprioceptive branches to the SCM muscle

Question 13

Function of the lesser occipital nerve:

Answer 13

(C2)

sensory & postganglionic sympathetic [gray ramus] innervation of the skin overlying the posterior-lateral aspect of the head and upper neck

Question 14

Function of the great auricular nerve:

Answer 14

(C2, 3)

sensory & postganglionic sympathetic [gray rami communicans] innervation of the skin overlying the upper SCM, lower parotid region, and ear

Question 15

Function of the transverse cervical nerve:

Answer 15

(C2,3)

sensory & postganglionic sympathetic [gray rami communicans] innervation of the skin overlying the lower SCM and anterior neck

Question 16

Function of the supraclavicular nerve

Answer 16

(C3, 4)

sensory & postganglionic sympathetic [gray rami communicans] innervation of the skin overlying the lower half of the posterior triangle of the neck

Question 17

Function of the proprioceptive branches to the trapezius and SCM (arise from the cervical ventral rami)

Answer 17

sensory & postganglionic sympathetic [gray rami communicans] innervation of the SCM and trapezius muscle

Question 18

What is the the common function of all the muscular branches that arise from the cervical ventral rami?

Answer 18

sensory, postganglionic sympathetic [gray ramus] and motor innervation to a particular muscle or a group of muscles