SENSORY INNERVATION OF THE HEAD AND NECK Flashcards
What nerve is responsible for the motor innervation to the muscles of facial expression ?
Branches of the Facial nerve ( C.N. VII)
Facial nerve paralysis
Bell’s Palsy
What structure provides sensory innervation to the face?
Branches of the Trigeminal nerve (C.N. V)
What are the three branches of the trigeminal nerve before emerging onto the face?
- Opthalamic
- Maxillary
- Mandibular
Nerve that distributes primarily to the face and scalp
Opthalamic Nerve
Maxillary nerve
Distributes primarily to the cheek and the area lateral to the orbit.
Nerve that distributes primarily to the chin and temporal region
Mandibular Nerve
What are the branches of the Opthalamic Nerve?
Supraorbital, Supratrochlear, External Nasal, Infratrochlear and Lacrimal Nerves
What are the branches of the Maxillary Nerve?
Zygomaticotemporal Nerve, Zygomaticofacial Nerve and the Infraorbital Nerve
What is the clinical significance of Infraorbital Nerve?
Most frequently injured due to blows to the face.
Common with boxers.
What are the branches of the Mandibular nerve?
Auriculotemporal nerve, Buccal nerve and the Mental nerve
Trigeminal Neuralgia (Tic Douloureux)
Condition characterized by sudden attacks of severe pain occurring in an area of sensory distribution of the trigeminal nerve.
Occurs most commonly in the Maxillary division of the trigeminal nerve.
Second most commonly found in the mandibular division.
Least commonly found in the opthalamic division.
Cause is unknown and this condition usually occurs unilaterally
Spinal Trigeminal Nucleus
Nucleus that extends down to C4 and is involved with pain reception from the face.
What is the sensory distribution of the posterior (dorsal) primary rami of cervical nerves 2-4?
Posterior aspect of the neck and scalp
Supplies the occipital region
Greater Occipital Nerve (posterior primary ramus of C2)
Supplies the upper part of the back of the neck
Third Occipital Nerve (posterior primary ramus of C3)
Supplies the lower part of the back of the neck
Posterior Primary Ramus of C4
Which cranial nerve is strictly a motor nerve?
C1. It has no posterior root carrying sensory fibers.
What is the sensory distribution of the anterior (ventral) primary rami of cervical nerves 2 to 4?
Anterior and lateral aspect of the neck
What forms the cervical plexus?
The anterior primary rami of C1, C2, C3 and C4.
C5, C6, C7 and C8 supply sensory innervation to?
The skin of the upper limb
What are the sensory braches of the Cervical Plexus?
Lesser Occipital Nerve (C2)
Great Auricular Nerve (C2, C3)
Transverse Cervical Nerve (C2, C3)
Supraclavicular Nerve (C3, C4)
Lesser Occipital Nerve (C2)
supplies the lateral part of the occipital region, posterior to the ear
Great Auricular Nerve (C2, C3)
supplies the angle of the mandible and the area inferior to the ear. It accompanies the external jugular vein.
Transverse Cervical Nerve (C2, C3)
Supplies the anterior surface of the neck (the throat)
Supraclavicular Nerve (C3, C4)
supplies the lateral surface of the neck.
What are the 3 subdivisions of the Supraclavicular Nerve?
(1) Medial Supraclavicular Nerve
(2) Intermediate Supraclavicular Nerve
(3) Lateral Supraclavicular Nerve
What do the motor fibers going to the infrahyoid (strap) muscles arise from?
Ansa cervicalis
What portion of the ansa cervicalis descends from the hypoglossal nerve to join the inferior root?
Superior root (C1, or C1 and C2)
What portion of the ansa cervicalis descends from the cervical nerve branches to join the superior root?
Inferior root (C2 and C3)
What muscles does the ansa cervicalis supply?
3 of the 4 infrahyoid muscles: sternohyoid, sternothyroid, and omohyoid
The thyrohyoid receives its innervation from what nerve?
C1 fibers through the hypoglossal nerve
Is the phrenic nerve considered part of the cervical plexus?
Usually, it originates from C3, C4 and C5.
The phrenic nerve gives motor innervation to the __________.
diaphragm
The phrenic nerve gives sensory innervation to ________________________.
some of the membranes of the thorax and abdomen
Where is the phrenic nerve found? Where does it run?
in the neck lying on the anterior surface of the anterior scalene muscle and runs vertically down the muscle into the thorax