| gonadal ridge | An elevation of thickened mesothelium and underlying mesenchyme on the ventromedial border of the embryonic mesonephros; the primordial germ cells become embedded in it, establishing it as the primordium of the testis or ovary. Synonym: genital ridge. (05 Mar 2000) |
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| mesonephric ridge | A ridge which, in early human embryos, comprises the entire urogenital ridge; however, later in development a more medial genital ridge, the potential gonad, is demarcated from it. See: urogenital ridge. Synonym: mesonephric fold. (05 Mar 2000) |
| ridge | 1. A (usually rough) linear elevation. See: crest. 2. In dentistry, any linear elevation on the surface of a tooth. 3. The remainder of the alveolar process and its soft tissue covering after the teeth are removed. Origin: A. S. Hyrcg, back, spine (05 Mar 2000) |
| ridge extension | An intraoral surgical operation for deepening the labial, buccal, and/or lingual sulci; it is performed to increase the intraoral height of the alveolar ridge in order to assist denture retention. (05 Mar 2000) |
| ridge relation | The positional relation of the mandibular ridge to the maxillary ridge. (05 Mar 2000) |
| ridge resorption | A loss in the volume and size of the alveolar portion of the mandible or maxilla. (05 Mar 2000) |
| pharyngeal ridge | A constant band of the superior pharyngeal constrictor muscle which sweeps posteriorly from the anterolateral part of the superior surface of the palatine aponeurosis. It creates a visible ridge when the superior constrictor is contracted, meeting the elevated soft palate to seal off the pharyngeal isthmus during swallowing. Synonym: pharyngeal ridge, sphincter of the pharyngeal isthmus, velopharyngeal sphincter. (05 Mar 2000) |
| milk ridge | Bandlike thickening of ectoderm in the embryo extending on either side from just below the axilla to the inguinal region; in human embryos, the mammary glands arise from primordia in the thoracic part of the ridge, the balance of the ridge disappearing; in some lower mammals which give birth to a litter of young, several milk glands develop along these lines. Synonym: mammary fold, milk line, milk ridge. (05 Mar 2000) |
| wolffian ridge | One of the paired longitudinal ridge's developing in the dorsal body wall of the embryo on either side of the dorsal mesentery; the ridge is formed at first by the growing mesonephros and later by the mesonephros and the gonad. Synonym: genital fold, wolffian ridge. (05 Mar 2000) |
| mylohyoid ridge | A ridge on the inner surface of the mandible running from a point inferior to the mental spine upward and backward to the ramus behind the last molar tooth; it gives attachment to the mylohyoid muscle and the lowermost part of the superior constrictor of the pharynx. Synonym: linea mylohyoidea, internal oblique line, mylohyoid ridge. (05 Mar 2000) |
| crest of alveolar ridge | The top of the alveolar ridge or residual ridge; the highest continuous surface of the ridge, but not necessarily the centre of the ridge. (05 Mar 2000) |
| primitive ridge | One of the paired ridge's on either side of the primitive groove. (05 Mar 2000) |
| pronator ridge | An oblique ridge on the anterior surface of the ulna, giving attachment to the pronator quadratus muscle. (05 Mar 2000) |
| pterygoid ridge of sphenoid bone | A rough ridge marking the angle of union of the temporal and infratemporal surfaces of the greater wing of the sphenoid bone. Synonym: crista infratemporalis, pterygoid ridge of sphenoid bone. (05 Mar 2000) |
| nasal ridge | An elevation on the lateral wall of the nasal cavity lying between the atrium of the middle meatus and the olfactory sulcus; it is formed by the mucous membrane covering the base of the ethmoidal crest of the maxilla. Synonym: nasal ridge. (05 Mar 2000) |