Cervical Plexus

Question 1

Ascending

Answer 1

1- Lesser Occipital n.
2- Great Auricular n.
3- Transverse Cervical n.

Question 2

Lesser Occipital n.

Answer 2

• C2

- Supplies skin of neck, scalp, posterosuperior ear

Question 3

Great auricular n.

Answer 3

C2, C3

Supplies skin over & around parotid gland, mastoid process, inferior ear, angle of mandible

Question 4

Transverse cervical n.

Answer 4

C2, C3

Supplies skin of anterior neck, deep to platysma

Question 5

Descending

Answer 5

Supraclavicular nn. (C3, C4)

Question 6

Supraclavicular nn.

Answer 6

(C3, C4)

Supplies skin of neck, superficial

Question 7

Deep branches

Answer 7

ALL MOTOR (mostly in anterior triangle)

C1 joins and rides on Hypoglossal n.

Ansa cervicalis – loops of nerves

Deep branches not associated with ansa cervicalis

Question 8

C1 joins and rides on Hypoglossal n.

Answer 8

Nerve to the geniohyoid – C1 (as rides with CN XII)

Nerve to the thyrohyoid – C1 (as rides with CN XII)

Question 9

Ansa cervicalis – loops of nerves

Answer 9

Superior root: C1
Nerve to the superior belly of the omohyoid – C1
Inferior root: C2, C3
Nerve to the sternothyroid – C1, C2, C3
Nerve to the sternohyoid – C1, C2, C3
Nerve to the inferior belly of omohyoid – C2, C3

Question 10

Deep branches not associated with ansa cervicalis

Answer 10

Nerve to rectus capitis lateralis – C1, C2
Nerve to the rectus capitis anterior – C1, C2
Nerve to the longus capitis – C1 – C4
Nerve to the longus coli – C2 – C8 (only C2-4 from cerv. plexus)
C3 and C4 contribute to innervation of middle scalene
Phrenic n.: largest contribution from C4, also receives from C3 & C5 (C5 not in cervical plexus); diaphragm

Question 11

Communicating Branches of Cervical Plexus

Answer 11

Cervical plexus roots receive gray communicating branches, most are from the superior cervical ganglion

Cervical plexus roots also have communicating branches with CN X and XI

Question 12

Sympathetic Chain

Answer 12

Located deep in anterior triangle (carotid sub-triangle) and root of neck

3 cervical chain ganglia are the extension of the sympathetic chain into the neck from the thorax

Question 13

3 cervical chain ganglia

Answer 13

Inferior cervical ganglion
Middle cervical ganglion
Superior cervical ganglion

Question 14

Inferior cervical ganglion

Answer 14

C7, C8

Sometimes fused with the 1st thoracic ganglion to form the cervicothoracic (stellate) ganglion

Question 15

Middle cervical ganglion

Answer 15

C5, C6

Smallest of the three cervical ganglia

Question 16

Superior cervical ganglion

Answer 16

C1-C4

Often the largest of the three cervical ganglia

Question 17

Nerve Supply in Neck

Answer 17

Brachial plexus:
Cranial nerves:
Cervical plexus:
Sympathetic chain

Question 18

Brachial plexus:

Answer 18

C5-T1 ventral rami

Posterior Triangle

Emerges between the anterior and middle scalene muscles

Question 19

Cranial nerves:

Answer 19

IX, X, XI, XII

Question 20

Cervical plexus

Answer 20

C1-C4 ventral rami

Question 21

CN IX

Answer 21

Glossopharyngeal Nerve

Branches are in submandibular & carotid triangles

In the neck provides:

Branchial motor to stylopharyngeus m.

Visceral sensory from
Pharynx
Carotid sinus (baroreceptor – regulates BP)
Carotid body (chemoreceptor – regulates heart rate and respiration)

Question 22

CN X

Answer 22

Vagus Nerve

In the anterior triangle and root of neck

Question 23

Vagus Nerve Branches

Answer 23

Pharyngeal (to pharyngeal plexus)

Superior laryngeal n.

Recurrent laryngeal n. – branchial motor to other muscles

Question 24

Superior laryngeal n.

Answer 24

Internal laryngeal n. – general sensory to larynx

External laryngeal n. – branchial motor to 1 muscle

Question 25

Recurrent laryngeal n

Answer 25

– branchial motor to other muscles Left side - Loops under arch of aorta, ascends to larynx Right side – Loops under subclavian artery, ascends to larynx

Question 26

CN XI

Answer 26

Accessory Nerve

Question 27

Accessory Nerve

Answer 27

Innervates SCM and trapezius (branchial motor) Exits jugular foramen, passes deep to and supplies the SCM, Enters posterior triangle (~1/3 of SCM on posterior aspect), Passes posterior and inferior in investing layer of deep cervical fascia toward trapezius (inferior 1/3 of muscle)

Question 28

CN XII

Answer 28

Hypoglossal Nerve

Question 29

Hypoglossal Nerve

Answer 29

Exits hypoglossal canal Descends behind posterior belly of digastric to the anterior triangle Loops up into the submandibular triangle Goes between the mylohyoid and hyoglossus muscles to the floor of the mouth to innervate muscles of the tongue

Question 30

Cervical Plexus Location:

Answer 30

Anteromedial to levator scapulae and middle scalene; deep to SCM

Question 31

Cervical Plexus Composed of:

Answer 31

Comprised of C1-C4 ventral rami Irregular series of loops and branches Superficial branches = cutaneous, general sensory Deep branches = motor Ansa cervicalis: C1-C3, Supplies 3 of 4 infrahyoid muscles