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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. Axons carrying information to and from the cranial nerves form a synapse first at these nuclei. Lesions occurring at these nuclei can lead to effects resembling those seen by the severing of nerve(s) they ...
The hypoglossal nucleus is a cranial nerve nucleus, found within the medulla.Being a motor nucleus, it is close to the midline. In the open medulla, it is visible as what is known as the hypoglossal trigone, a raised area (medial to the vagal trigone) protruding slightly into the fourth ventricle.
The paramedian pontine reticular formation (PMPRF) is involved in coordinating horizontal conjugate eye movements and saccades. To do so, besides projecting to the ibsilateral abducens nucleus, the PMPRF projects fibers through the MLF to the contralateral oculomotor nucleus (specifically, those of its motor neurons that innervate the medial rectus muscle).
Neurons of the SN are notably functionally arranged roughly length-wise along the nucleus: gustatory neurons are situated rostrally (with afferents from the anterior part of the tongue and roof of oral cavity rostral-most, and those from the larynx and epiglottis more caudally placed); gastrointestinal, cardiovascular, respiratory neurons are situated more caudally.
The ventral portion of the medulla oblongata contains the medullary pyramids. These two ridge-like structures travel along the length of the medulla oblongata and are bordered medially by the anterior median fissure. They each have an anterolateral sulcus along their lateral borders, where the hypoglossal nerve emerges from.
The nucleus ambiguus controls the motor innervation of ipsilateral muscles of the soft palate, pharynx, larynx, and upper esophagus. Lesions of nucleus ambiguus result in nasal speech, dysphagia, dysphonia, and deviation of the uvula toward the contralateral side. Preganglionic parasympathetic to the heart also flow through the external ...
Name Location Notes medial vestibular nucleus (dorsal or chief vestibular nucleus) : medulla (floor of fourth ventricle) : corresponding to the lower part of the area acustica in the rhomboid fossa; [citation needed] the caudal end of this nucleus is sometimes termed the descending or spinal vestibular nucleus.
Ten of the twelve pairs of cranial nerves either target or are sourced from the brainstem nuclei. [14]: 725 The nuclei of the oculomotor nerve (III) and trochlear nerve (IV) are located in the midbrain. The nuclei of the trigeminal nerve (V), abducens nerve (VI), facial nerve (VII) and vestibulocochlear nerve (VIII) are located in the pons.