What is Trochlear nucleus?
What is Trochlear nucleus?
The trochlear nucleus is a small, ovoid group of neurons nestled in the medial longitudinal fasciculus of the caudal midbrain (Fig. 28.8; see p. 420). These motor neurons supply the contralateral superior oblique muscle.
How many nucleus does the Trochlear nerve have?
The oculomotor nerve and trochlear nerve are the only two cranial nerves with nuclei in the midbrain, other than the trigeminal nerve, which has a midbrain nucleus called the mesencephalic nucleus of trigeminal nerve, which functions in preserving dentition….
| Trochlear nucleus | |
|---|---|
| FMA | 54518 |
| Anatomical terms of neuroanatomy |
Where are Trochlear nucleus located?
midbrain
The nucleus is located in the midbrain at the level of the inferior colliculus ventral and medial periaqueductal grey and dorsal to the medial longitudinal fasciculus. It lies just caudal to the oculomotor nucleus and Edinger-Westphal nucleus.
What is the nucleus of the olfactory nerve?
A cranial nerve nucleus is a collection of neurons (gray matter) in the brain stem that is associated with one or more of the cranial nerves….Location.
| Olfactory nerve | Olfactory bulb |
|---|---|
| Oculomotor nerve | Oculomotor nucleus Edinger-Westphal nucleus |
| Trochlear nerve | Trochlear nucleus |
What is the main function of the trochlear nerve?
The trochlear nerve is one of 12 sets of cranial nerves. It enables movement in the eye’s superior oblique muscle. This makes it possible to look down. The nerve also enables you to move your eyes toward your nose or away from it.
What is special about the trochlear nerve?
The trochlear nerve is unique among the cranial nerves in several respects: It is the smallest nerve in terms of the number of axons it contains. It has the greatest intracranial length. It is the only cranial nerve that exits from the dorsal (rear) aspect of the brainstem.
What does the Trochlear do?
What is a nerve nucleus?
In neuroanatomy, a nucleus (plural form: nuclei) is a cluster of neurons in the central nervous system, located deep within the cerebral hemispheres and brainstem. Nuclei are connected to other nuclei by tracts, the bundles (fascicles) of axons (nerve fibers) extending from the cell bodies.
What is olfactory nerve function?
The olfactory nerve is a solely sensory nerve and conveys the sense of smell. Its receptors are located in the olfactory mucosa under the roof of the nasal cavity.
What does the abducens nerve control?
Cranial nerve six (CN VI), also known as the abducens nerve, is one of the nerves responsible for the extraocular motor functions of the eye, along with the oculomotor nerve (CN III) and the trochlear nerve (CN IV).
How does the abducens nerve move the eye?
The abducens nerve leaves the brainstem at the junction of the pons and the medulla, medial to the facial nerve. It runs upwards and forwards from this position to reach the eye. It then enters the orbit through the superior orbital fissure and innervates the lateral rectus muscle of the eye.
Where is the trochlear nucleus located?
The trochlear nucleus is located in the dorsal midbrain, ventral to the periaqueductal grey matter . Its fibers course dorsally and decussate dorsal to the periaqueductal grey matter before exiting the brainstem immediately below the inferior colliculus .
What is the function of the trochlear nerve?
Therefore, the trochlear nerve (CN VI) is responsible for inward rotation, depression, and abduction of the eyeball contralateral to the nucleus. The abducens (also called abducent) nerve (CN VI) is the last of the three visual motor nerves.
Where is the trochlear nerve located in the cavernous sinus?
Cavernous sinus portion. Within the cavernous sinus, the trochlear nerve is located initially below the oculomotor nerve in the lateral wall of the sinus, although by the time it reaches the superior orbital fissure, it lies above it (outside the tendinous ring).
