- Ammon h. [TA] one of the two interlocking gyri composing the hippocampus, the other being the dentate gyrus. Based on cytoarchitectural features, Ammon h. can be divided into region I [TA] (regio I cornus ammonis [TA]), region II [TA] (regio II cornus ammonis [TA]), region III [TA] (regio III cornus ammonis [TA]) and region IV [TA] (regio IV cornus ammonis [TA]). SYN: cornu ammonis. [G. Ammon, the Egyptian deity Amun]
- anterior h. [TA] 1. the frontal or anterior division of the lateral ventricle of the brain, extending forward from Monro interventricular foramen; See lateral ventricle. 2. the anterior h. or ventral gray column of the spinal cord as appearing in cross section. The anterior h. is composed of the spinal lamina VIII-IV [TA] of Rexed with portions of VII also extending into its geographical boundaries in lumbosacral and cervical levels. The nuclei of the anterior h. are the anterolateral nucleus [TA] or ventrolateral nucleus [TAalt] (nucleus anterolateralis [TA]), anterior nucleus [TA] (nucleus anterior [TA]), anteromedial nucleus [TA] or ventromedial nucleus [TAalt], (nucleus anteromedialis [TA]), posterolateral nucleus [TA] or dorsolateral nucleus [TAalt] (nucleus posterolateralis [TA]), retroposterior lateral nucleus [TA] or retrodorsal lateral nucleus [TAalt] (nucleus retroposterolateralis [TA]), posteromedial nucleus [TA] or dorsomedial nucleus [TAalt] (nucleus posteromedialis [TA]), central nucleus [TA] (nucleus centralis [TA]) and the accessory nucleus and phrenic nucleus, both found in cervical levels only. SEE ALSO: anterior column, gray columns, under column. SYN: cornu anterius [TA], ventral h..
- cutaneous h. a protruding keratotic growth of the skin; the base may show changes of actinic keratosis or carcinoma. SYN: cornu cutaneum, warty h..
- greater h. of hyoid bone [TA] the larger and more lateral of the two processes on either side of the hyoid bone. SYN: cornu majus ossis hyoidei [TA].
- inferior h. a lower or downward prolongation of a part or structure of the body. SYN: cornu inferius [TA].
- inferior h. of falciform margin of saphenous opening [TA] the lower part of the falciform margin of the opening in the fascia lata through which the greater saphenous vein passes. SYN: cornu inferius marginis falciformis hiatus sapheni [TA], crus inferius marginis falciformis hiatus sapheni.
- inferior h. of lateral ventricle the part of the lateral ventricle extending downward and forward into the medial part of the temporal lobe. See lateral ventricle. SYN: cornu inferius ventriculi lateralis [TA], cornu temporale ventriculi lateralis [TA], temporal h. [TA].
- inferior h. of thyroid cartilage [TA] one of the pair of downward prolongations at the back of the thyroid cartilage; it articulates on each side with the cricoid cartilage. SYN: cornu inferius cartilaginis thyroideae [TA].
- lateral h. [TA] the small lateral gray column of the spinal cord as appearing in transverse section containing the interomedial cell column. SEE ALSO: gray columns, under column. SYN: cornu laterale [TA].
- lesser h. of hyoid [TA] the shorter and more medial of the two processes on either side of the hyoid. SYN: cornu minus ossis hyoidei [TA], styloid cornu.
- posterior h. 1. the occipital or posterior division of the lateral ventricle of the brain, extending backward into the occipital lobe; SEE ALSO: posterior column. 2. [TA] the posterior h. or gray column of the spinal cord as appearing in cross section. The posterior h. [TA] or dorsal h. [TAalt] contains spinal laminae I-VI [TA] of Rexed. The nuclei of the posterior h. are the marginal nucleus [TA] (nucleus marginalis [TA]), gelatinous substance [TA] (substantia gelatinosa [TA]), nucleus proprius [TA], secondary visceral grey substance [TA] (substantia visceralis secundaria [TA]), internal basilar nucleus [TA] (nucleus basilar internus [TA]), medial cervical nucleus [TA] (nucleus cervicalis medialis [TA]), posterior nucleus of lateral funiculus [TA] (nucleus posterior funiculi lateralis [TA]) and the lateral cervical nucleus. SYN: cornu posterius ventriculi lateralis [TA], cornu posterius [TA], occipital h. [TA], cornu of spinal cord.
- horns of saphenous opening inferior h. of falciform margin of saphenous opening, superior h. of falciform margin of saphenous opening.
- superior h. of falciform margin of saphenous opening [TA] the upper part of the falciform margin of the opening in the fascia lata through which the greater saphenous vein passes. SYN: cornu superius marginalis falciformis [TA], Burns falciform process, Burns ligament, crus superius marginis falciformis hiatus sapheni, Hey ligament.
- superior h. of thyroid cartilage [TA] one of the pair of upward prolongations from the thyroid cartilage to which the lateral hyothyroid ligament attaches. SYN: cornu superius cartilaginis thyroideae [TA].
- uterine h., h. of uterus [TA] the portion of the uterus to which the intramural section of the uterine tube enters on either the right or left. SYN: cornu uteri [TA].
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horn 'hȯ(ə)rn n
1 a) one of the usu. paired bony processes that arise from the head of many ungulates and that are found in some extinct mammals and reptiles esp one of the permanent paired hollow sheaths of keratin usu. present in both sexes of cattle and their relatives that function chiefly for defense and arise from a bony core anchored to the skull
b) the tough fibrous material consisting chiefly of keratin that covers or forms the horns of cattle and related animals, hooves, or other horny parts (as claws or nails)
2) CORNU
horned 'hȯ(ə)rnd adj
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n.
(in anatomy) a process, outgrowth, or extension of an organ or other structure. It is often paired. In the spinal cord crescent-shaped areas of grey matter (seen in cross section) are known as the dorsal and ventral horns.
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(horn) [L. cornu] 1. a pointed projection, often paired, found on the heads of various animals. 2. cornu (def. 2). 3. an excrescence or projection resembling the horn of an animal.Medical dictionary. 2011.