Session 11: Cervical Plexus Flashcards
Where can the cervical plexus be found?
Posterior triangle within the prevertebral layer of the cervical fascia.
What is the cervical plexus made up of?
Anterior rami of C1-C4
Main motor branches of the cervical plexus.
Nerve to genohyoid and thyrohyoid
Ansa cervicalis
Phrenic nerve
Where are the motor branches found in relation to the sensory branches?
Deep to the sensory branches.
Root value of phrenic nerve.
C3-C5
Route and supply of the phrenic nerve.
Originates from the cervical plexus and descends down the anterior scalene to enter the thoracic cavity.
It then descends anterior to the root of the lung and innervates the diaphragm.
Root value of the nerve to genohyoid and thyrohoid.
C1
Action of geniohyoid?
Moves hyoid bon anteriorly and upwards to expand the airways.
Action of thyrohyoid.
Depresses the hyoid bone and elevates the larynx.
What does the nerves to geniohyoid and thyrohyoid travel with?
The hypoglossal nerve
Root value of ansa cervicalis.
C1-C3
What does ansa cervicalis innervate?
Infrahyoids
What do the sensory branches of the cervical plexus innervate?
Skin of neck, upper thorax, scalp and ear.
Explain the common route of the sensory branches of the cervical plexus.
Enter the skin at the middle point of the posterior border of SCM.
What is Erb’s point?
The point of which the sensory branches exit the cervical plexus.
Middle point of the posterior border of SCM.
Main sensory branches of the cervical plexus.
Greater auricular nerve
Transverse cervical nerve
Lesser occipital nerve
Supraclavicular nerves
Nerve roots of greater auricular nerve.
C2,C3
What does the greater auricular nerve innervate?
External ear and the skin over parotid gland.
Also comunicates with the auricular branch of the vagus nerve and the posterior auricular branch of facial nerve.
Nerve roots of transverse cervical nerve
C2,C3
What does the transverse cervical nerve innervate.
Anterior skin of neck and piereces deep cervical fascia to also supply anterolateral skin of neck and sternum.
Nerve roots of lesser occipital nerve.
Mainly C2
In some individuals C3 can contribute slightly.
What does the lesser occipital nerve innervate?
Curves around the accessory nerve to supply the posterosuperior scalp.
Nerve roots of the supraclavicular nerves.
C3,C4
What does the supraclavicular nerves innervate?
Supraclavicular fossa
Upper thoracic region
Sternoclavicular joint
