Cervical Plexus Flashcards
Ascending
1- Lesser Occipital n.
2- Great Auricular n.
3- Transverse Cervical n.
Lesser Occipital n.
- C2
- Supplies skin of neck, scalp, posterosuperior ear
Great auricular n.
C2, C3
Supplies skin over & around parotid gland, mastoid process, inferior ear, angle of mandible
Transverse cervical n.
C2, C3
Supplies skin of anterior neck, deep to platysma
Descending
Supraclavicular nn. (C3, C4)
Supraclavicular nn.
(C3, C4)
Supplies skin of neck, superficial
Deep branches
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
C1 joins and rides on Hypoglossal n.
Nerve to the geniohyoid – C1 (as rides with CN XII)
Nerve to the thyrohyoid – C1 (as rides with CN XII)
Ansa cervicalis – loops of nerves
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
Deep branches not associated with ansa cervicalis
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
Communicating Branches of Cervical Plexus
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
Sympathetic Chain
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
3 cervical chain ganglia
Inferior cervical ganglion
Middle cervical ganglion
Superior cervical ganglion
Inferior cervical ganglion
C7, C8
Sometimes fused with the 1st thoracic ganglion to form the cervicothoracic (stellate) ganglion
Middle cervical ganglion
C5, C6
Smallest of the three cervical ganglia
Superior cervical ganglion
C1-C4
Often the largest of the three cervical ganglia
Nerve Supply in Neck
Brachial plexus:
Cranial nerves:
Cervical plexus:
Sympathetic chain
Brachial plexus:
C5-T1 ventral rami
Posterior Triangle
Emerges between the anterior and middle scalene muscles
Cranial nerves:
IX, X, XI, XII
Cervical plexus
C1-C4 ventral rami
CN IX
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)
CN X
Vagus Nerve
In the anterior triangle and root of neck
Vagus Nerve Branches
Pharyngeal (to pharyngeal plexus)
Superior laryngeal n.
Recurrent laryngeal n. – branchial motor to other muscles
Superior laryngeal n.
Internal laryngeal n. – general sensory to larynx
External laryngeal n. – branchial motor to 1 muscle
Recurrent laryngeal n
– branchial motor to other muscles
Left side - Loops under arch of aorta, ascends to larynx
Right side – Loops under subclavian artery, ascends to larynx
CN XI
Accessory Nerve
Accessory Nerve
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)
CN XII
Hypoglossal Nerve
Hypoglossal Nerve
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
Cervical Plexus Location:
Anteromedial to levator scapulae and middle scalene; deep to SCM
Cervical Plexus Composed of:
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
