| vestibular nuclei | The four cellular masses in the floor of the fourth ventricle giving rise to a widely dispersed special sensory system. (12 Dec 1998) |
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| vestibulocochlear nuclei | The combined cochlear and vestibular nuclei in the brainstem that receive the incoming fibres of the eighth cranial nerve. See: vestibular nucleus. Synonym: nuclei nervi vestibulocochlearis. (05 Mar 2000) |
| cauda nuclei caudati | The elongated posterior extension of the caudate nucleus that parallels the body and inferior horn of the lateral ventricle. Synonym: cauda nuclei caudati, cauda striati. (05 Mar 2000) |
| medial accessory olivary nucleus | A detached part of the olivary nucleus medial to the latter's main body, against the lateral side of the medial lemniscus and pyramidal tract. Synonym: nucleus olivaris accessorius medialis. (05 Mar 2000) |
| cerebellar nuclei | Four accumulations of gray substance embedded in the white substance of the cerebellum, comprising the nucleus dentatus, nucleus emboliformis, nucleus globosus, and nucleus fastigii. (12 Dec 1998) |
| reticular nuclei of the brainstem | The vaguely delineated cell groups composing the gray matter of the reticular formation of the rhombencephalon and mesencephalon. In general, large-celled territories occupy the medial two-thirds of the reticular formation: gigantocellular nucleus of medulla oblongata, nuclei tegmenti pontis caudalis and oralis. Smaller groups of reticular nuclei are found laterally and in paramedian locations; lateral nuclei receive sensory collaterals and project medially; paramedian reticular nuclei largely project to the cerebellum. See: reticular formation. (05 Mar 2000) |
| perihypoglossal nuclei | Nuclei found in the floor of the 4th ventricle in relation to the hypoglossal nucleus, includes the prepositus and intercalated nuclei and the nucleus of Roller. (05 Mar 2000) |
| Gudden's tegmental nuclei | Collective term for two small round cell groups in the caudal part of the midbrain (caudal pontine tegmental nucleus, nucleus tegmenti pontis caudalis and oral pontine tegmental nucleus, nucleus tegmenti pontis oralis), associated with the mamillary body by way of the mamillary peduncle and mamillotegmental tract. Synonym: nuclei tegmenti, Gudden's tegmental nuclei. (05 Mar 2000) |
| cochlear nuclei | The nucleus cochlearis dorsalis and nucleus cochlearis ventralis, located on the dorsal and lateral surface of the inferior cerebellar peduncle, in the floor of the lateral recess of the rhomboid fossa. They receive the incoming fibres of the cochlear part of the vestibulocochlear nerve and are the major source of origin of the lateral lemniscus or central auditory pathway. Synonym: cochlear nuclei, nuclei nervi cochlearis. (05 Mar 2000) |
| placenta, accessory | An extra placenta separate from the main placenta. Also called a succenturiate or supernumerary placenta. Placenta accreta: the abnormal adherence of the chorionic villi to the myometrium. The vascular processes of the chorion (a foetal membrane that enters into the formation of the placenta) grow directly in the myometrium (the muscular portion of the uterus). Normally there is tissue intervening between the chorionic villi and the myometrium. Here there is not. The word accreta comes from the latin accretio from ad meaning to or toward + crescere meaning to grow. Placenta accreta can progress to placenta percreta. (12 Dec 1998) |
| companion lymph nodes of accessory nerve | The nodes of the lateral deep cervical group that are located along the accessory nerve; their efferent vessels pass to the supraclavicular lymph nodes. Synonym: companion lymph nodes of accessory nerve, nodi lymphatici comitantes nervi accessorii. (05 Mar 2000) |
| motor nuclei | Collections of motor neurons (forming a continuous column in the spinal cord, discontinuous in the medulla and pons) giving origin to the spinal and cranial motor nerves. Synonym: nuclei originis, motor nuclei. (05 Mar 2000) |
| corpus nuclei caudati | The suprathalamic part of the caudate nucleus lying in the floor of the central part of the lateral ventricle. Synonym: corpus nuclei caudati. (05 Mar 2000) |
| pontine nuclei | The massive gray matter filling the basilar pons. The nuclei are of fairly homogeneous architecture and project to the cortex of the contralateral cerebellar hemisphere by way of the middle cerebellar peduncle. Their main afferents come from the entire extent of the cerebral neocortex by way of the longitudinal pontine bundles (corticopontine fibres); thus, the pontine nuclei form a major way-station in the impulse conduction from the cerebral cortex of one hemisphere to the posterior lobe of the opposite cerebellum. Synonym: nuclei pontis, pontine gray matter. (05 Mar 2000) |
| cranial root of accessory nerve | <anatomy, nerve> The roots of the accessory nerve which arise from the medulla; the nerve fibres of the cranial root join the intracranial portion of the vagus nerve and are distributed to the pharyngeal plexus, providing the motor innervation of the soft palate (except the tensor veli palati) and the pharynx. Synonym: pars vagalis nervi accessorii, radices craniales, accessory portion of spinal accessory nerve, cranial roots, vagal part of accessory nerve, vagal part. (05 Mar 2000) |