| epiotic centre | The centre of ossification of the petrous part of the temporal bone that appears posterior to the posterior saemicircular canal. (05 Mar 2000) |
|---|---|
| expiratory centre | The region of the medulla oblongata that is electrically active during expiration and where electrical stimulation produces sustained expiration. (05 Mar 2000) |
| Kerckring's centre | An occasional independent ossification centre in the occipital bone; it appears in the posterior margin of the foramen magnum at about the sixteenth week of gestation. Synonym: Kerckring's ossicle. (05 Mar 2000) |
| feeding centre | A region of the lateral zone of the hypothalamus, electrical stimulation of which in the rat elicits uninterrupted eating; destruction of the region causes long-lasting anorexia. (05 Mar 2000) |
| fibrillar centre | <cell biology> Location of the nucleolar ribosomal chromatin at telophase: as the nucleolus becomes active the ribosomal chromatin and associated ribonucleoprotein transcripts compose the more peripherally located dense fibrillar component. (12 Nov 1997) |
| alveolar ridge | That portion of bone in either the maxilla or the mandible which surrounds and supports the teeth. (12 Dec 1998) |
| alveolar ridge augmentation | Preprosthetic surgery involving rib, cartilage, or iliac crest bone grafts, usually autologous, or synthetic implants for rebuilding the alveolar ridge. (12 Dec 1998) |
| apical ectodermal ridge | The layer of surface ectodermal cells at the apex of the embryonic limb bud; considered to exert an inductive influence on the condensation of underlying mesenchyme. (05 Mar 2000) |
| basal ridge | That portion of bone in either the maxilla or the mandible which surrounds and supports the teeth. (12 Dec 1998) |
| buccocervical ridge | A convexity within the cervical third of the buccal surface of molars. (05 Mar 2000) |
| buccogingival ridge | A distinct ridge on the buccal surface of a deciduous molar tooth, approximately 1.5 mm from the crown-root junction. (05 Mar 2000) |
| bulbar ridge | One of two spiral subendocardial thickenings in the embryonic bulbus cordis; when they fuse, they divide the bulbus into the aorta and pulmonary artery. (05 Mar 2000) |
| bulboventricular ridge | An elevation on the inner surface of the embryonic heart at four to five weeks; it indicates the division between the developing ventricles and the bulbus cordis. (05 Mar 2000) |
| palatine ridge | A rather narrow, low elevation in the centre of the hard palate that extends from the incisive papilla posteriorly over the entire length of the mucosa of the hard palate. Synonym: raphe palati, palatine ridge. (05 Mar 2000) |
| ganglion ridge | A group of embryonic cells that separate from the neural plate during neurulation and migrate to give several different lineages of adult cells: the spinal and autonomic ganglia, the glial cells of the peripheral nervous system and nonneuronal cells, such as chromaffin cells, melanocytes and some haemopoietic cells. (18 Nov 1997) |