Where does facial nerve Decussate?
Where does facial nerve Decussate?
It arises from the brain stem and extends posteriorly to the abducens nerve and anteriorly to the vestibulocochlear nerve. It courses through the facial canal in the temporal bone and exits through the stylomastoid foramen after which it divides into terminal branches at the posterior edge of the parotid gland.
What are the divisions of the trigeminal nerve?
It contains the sensory cell bodies of the 3 branches of the trigeminal nerve (the ophthalmic, mandibular, and maxillary divisions). The ophthalmic and maxillary nerves are purely sensory. The mandibular nerve has sensory and motor functions.
What is root entry zone of trigeminal nerve?
The root entry zone, i.e. the zone where peripheral myelination transitions to central myelination, was defined as the area from the site of entry of the trigeminal nerve into the pons to 7 mm peripherally along the nerve (Peker et al., 2006).
Does trigeminal nerve Decussate?
At its rostral end, this nucleus is contiguous with the pontine sensory nucleus of the trigeminal nerve. From these nuclei, axons decussate and extend to the contralateral thalamus.
Does the hypoglossal nerve Decussate?
The nerve arises from the hypoglossal nucleus in the medulla as a number of small rootlets, passes through the hypoglossal canal and down through the neck, and eventually passes up again over the tongue muscles it supplies into the tongue….
| Hypoglossal nerve | |
|---|---|
| FMA | 50871 |
| Anatomical terms of neuroanatomy |
What are the branches of maxillary nerve?
Branches
- Zygomatic nerve (zygomaticotemporal nerve, zygomaticofacial nerve), through the Inferior orbital fissure.
- Nasopalatine nerve, through the sphenopalatine foramen.
- Posterior superior alveolar nerve.
- Greater and lesser palatine nerves.
- Pharyngeal nerve.
How many branches does the facial nerve have?
five
The facial nerve then enters the parotid gland, and branches into five divisions (see above). The facial nerve has five main branches, although the anatomy can vary somewhat between individuals. The branches are, from top to bottom: frontal (or temporal), zygomatic, buccal, marginal mandibular, and cervical.
What is the main nerve branch consisting of the top 1/3 of the face?
Structure. The trigeminal nerve is the largest of the cranial nerves. Its name, trigeminal, means three twins. It is derived from the fact that each nerve, one on each side of the pons, has three major branches: the ophthalmic nerve (V1 in the illustration below), the maxillary nerve (V2), and the mandibular nerve (V3) …
Does the trigeminal nerve cross?
From the spinal trigeminal nucleus, secondary fibers cross the midline and ascend in the trigeminothalamic (quintothalamic) tract to the contralateral thalamus. Pain-temperature fibers are sent to multiple thalamic nuclei.
Where does the trigeminal pathway Decussate?
Axons of the second-order neurons then decussate to enter the trigeminal lemniscus in the midbrain and then ascend to the ventral posteromedial nucleus of the contralateral thalamus, forming the ventral trigeminothalamic tract.
What is the difference between the motor and sensory branches of trigeminal?
The motor nerve branch of the trigeminal nerve is smaller than the sensory branches and exits from the brainstem through the root of the trigeminal nerve.
How is the cisternal segment of the trigeminal nerve accessed?
In brief, the cisternal segment of the trigeminal nerve is accessed via a 2.0 × 1.5-cm retromastoid craniectomy. With the aid of microscopic or endoscopic illumination, the surgeon identifies compressive vessels (Fig. 3) and decompresses the nerve by transposing the artery or vein from the nerve.
What is the pathophysiology of trigeminal neuralgia?
Trigeminal neuralgia is a debilitating pain syndrome in the sensory distribution of the trigeminal nerve. Compression of the cisternal segment of the trigeminal nerve by a vessel, usually an artery, is considered the most common cause of trigeminal neuralgia. A number of additional lesions may affec …
What is the difference between proximal and distal compression of trigeminal nerve?
Proximal vascular compression of the cisternal segment of the trigeminal nerve is considered more likely to be clinically relevant, whereas distal compression is less likely to be the cause of a patient’s symptoms. Fig. 2 —48-year-old man with sudden onset of unilateral hearing loss.
