Table of Contents
Where is the facial nerve nuclei located?
Structure. The nucleus is situated in the caudal portion of the ventrolateral pontine tegmentum. Its axons take an unusual course, traveling dorsally and looping around the abducens nucleus, then traveling ventrally to exit the ventral pons medial to the spinal trigeminal nucleus.
Where does the abducens nerve originate?
The abducens nerve originates from a set of neural cells that are found in the ventral aspect of the pons. It then emerges from the brainstem at the pontomedullary junction to enter the subarachnoid space, coursing upward between the pons and clivus to enter the Dorello canal.
What nucleus is facial nerve?
The facial nerve is comprised of three nuclei: The main motor nucleus. The parasympathetic nuclei. The sensory nucleus.
What number is facial nerve?
7th cranial nerve
The facial nerve is the 7th cranial nerve and carries nerve fibers that control facial movement and expression. The facial nerve also carries nerves that are involved in taste to the anterior 2/3 of the tongue and producing tears (lacrimal gland).
How do you test for the sixth cranial nerve?
- Usually, doctors can easily identify a 6th cranial nerve palsy, based on results of a neurologic examination.
- An ophthalmoscope.
- Computed tomography (CT) or, preferably, magnetic resonance imaging (MRI) of the brain is done to exclude tumors and other abnormalities that may be increasing pressure within the skull.
What layer is the facial nerve located?
The fifth layer is the facial nerve, which is discussed in detail below.
What is diabetic palsy?
Diabetic oculomotor nerve palsies, also called ischemic third nerve palsies, are the most common etiologic subset of oculomotor nerve palsy in adults. Diabetic oculomotor nerve palsies typically present with ptosis and diplopia, but pupillary function is often spared.
Where is the abducens nerve located in the face?
The abducens nucleus is a small nucleus situated at the upper part of the rhomboid fossa beneath the colliculus facialis within the pons. It is the most medial of the nerves emerging immediately below the pons ( facial nerve and vestibulocochlear nerve lateral to it) at the pontomedullary junction into the prepontine cistern.
Where is the facial nucleus located in the brain?
The facial nucleus is an aggregation of motor neurons in the ventrolateral region of the lower pontine tegmentum, at the level of the pons in the brain stem.
Where do the axons of the abducens nucleus go?
Within the abducens nucleus, lateral rectus motor neurons intermix with internuclear neurons that send their axons across to the opposite MLF and then to the contralateral cranial nerve III. Axons of cranial nerve VI course almost directly ventral and exit from the pons near the midline.
Where are the motor neons of the facial nerve located?
The upper motor neuron (UMN) of the facial nerve is located in the primary motor cortex of the frontal lobe. UMN axons descend ipsilaterally as the corticobulbar tract via the genu of the internal capsule and reach the facial nucleus in the pontine tegmentum. The facial nucleus is divided into a dorsal and ventral region.