| IOA | inner optic anlage; International Osteopathic Association |
|---|---|
| ION | ischemic optic neuropathy |
| IOT | intraocular tension; intraocular transfer; ipsilateral optic tectum |
| LHON | Leber hereditary optic neuropathy |
| LOA | leave of absence; Leber optic atrophy; left occipitoanterior [fetal position] |
| 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) |
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| 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) |
| hilum nuclei dentati | The mouth of the flasklike dentate nucleus of the cerebellum, directed inward, and giving exit to many of the fibres which compose the superior cerebellar peduncle or brachium conjunctivum. Synonym: hilum nuclei dentati. (05 Mar 2000) |
| hilum nuclei olivaris | The medially oriented opening in the folded cell layer composing the inferior olivary nucleus through which the efferent fibres of the nucleus make their exit. Synonym: hilum nuclei olivaris. (05 Mar 2000) |
| secondary sensory nuclei | Nuclei terminales, collective term indicating those nerve cell groups in the rhombencephalon and spinal cord in which the afferent fibres of the spinal and cranial nerves terminate. Synonym: nuclei terminationis, secondary sensory nuclei. (05 Mar 2000) |
| sensory nuclei | A group of cell bodies that receive afferent (sensory) input from the periphery. (05 Mar 2000) |
| septal nuclei | Neural nuclei situated in the septal region of the diencephalon. (12 Dec 1998) |
| sole nuclei | An accumulation of skeletal muscle fibre nuclei at the myoneural junction. (05 Mar 2000) |
| somatic motor nuclei | Collective term indicating the motor nuclei innervating the tongue musculature (hypoglossal nucleus) and the extraocular eye muscles (abducens nucleu, trochlear nucleus, and oculomotor nucleus). (05 Mar 2000) |
| special visceral efferent nuclei | Collective term for those motoneuronal nuclei of the brainstem (n. Ambiguus, facial motor nucleus, motor nucleus of the trigeminus) that develop from the branchiomotor column of the embryo and innervate striated muscle fibres (muscles of mastication, facial musculature, pharynx and vocal cord muscles) developed from the mesenchyme of the branchial arches. Synonym: special visceral efferent nuclei, special visceral motor nuclei. (05 Mar 2000) |
| special visceral motor nuclei | Collective term for those motoneuronal nuclei of the brainstem (n. Ambiguus, facial motor nucleus, motor nucleus of the trigeminus) that develop from the branchiomotor column of the embryo and innervate striated muscle fibres (muscles of mastication, facial musculature, pharynx and vocal cord muscles) developed from the mesenchyme of the branchial arches. Synonym: special visceral efferent nuclei, special visceral motor nuclei. (05 Mar 2000) |