| DREZ | dorsal root entry zone |
|---|---|
| DRL | dorsal root, lumbar; drug-related lupus |
| DRP | digoxin reduction product; dorsal root potential; dystrophin-related protein |
| DRR | digitally reconstructed radiograph; Division of Research Resources [NIH]; dorsal root reflex |
| DRT | dorsal root, thoracic |
| root hair cell | <botany> Root epidermal cell, part of which projects from the root surface as a thin tube, thus increasing the root surface area and promoting absorption of water and ions. (18 Nov 1997) |
|---|---|
| root nodule | <plant biology> Globular structure formed on the roots of certain plants, notably legumes and alder, by symbiotic association between the plant and a nitrogen fixing microorganism (Rhizobium in the case of legumes and Frankia in the case of alder and a variety of other plants). (18 Nov 1997) |
| root of facial nerve | <anatomy, nerve> Fibres running from the facial motor nucleus upward to the facial colliculus where they curve around the abducens nucleus and then pass peripherally between the superior olive and sensory nucleus of the trigeminal, to emerge as the facial nerve from the pontomedullary groove. Synonym: radix nervi facialis. (05 Mar 2000) |
| root of foot | Origin: NL, fr. Gr. The flat of the foot, the edge of the eyelid. Cf. 2d Tarse. 1. <anatomy> The ankle; the bones or cartilages of the part of the foot between the metatarsus and the leg, consisting in man of seven short bones. A plate of dense connective tissue or cartilage in the eyelid of man and many animals. Synonym: tarsal cartilage, and tarsal plate. 2. <zoology> The foot of an insect or a crustacean. It usually consists of form two to five joints. Source: Websters Dictionary (01 Mar 1998) |
| root of lung | All the structures entering or leaving the lung at the hilum, forming a pedicle invested with the pleura; includes the bronchi, pulmonary artery and veins, bronchial arteries and veins, lymphatics, and nerves. Synonym: radix pulmonis. (05 Mar 2000) |
| root of mesentry | The origin of the mesentery of the small intestine (jejunum and ileum) from the posterior parietal peritoneum; about 9 inches (23 cm.) in length, it extends from the duodenojejunal flexure (just to the left of the midline at the L2 vertebral level) to the ileocaecal junction (iliac fossa). Synonym: radix mesenterii. (05 Mar 2000) |
| root of nail | The proximal end of the nail, concealed under a fold of skin. Synonym: radix unguis. (05 Mar 2000) |
| root of nose | The upper least protruding portion of the external nose situated between the two orbits. Synonym: radix nasi. (05 Mar 2000) |
| root of penis | The proximal attached part of the penis, including the two crura and the bulb. Synonym: radix penis. (05 Mar 2000) |
| root of tongue | The posterior attached portion of the tongue. Synonym: radix linguae, base of tongue. (05 Mar 2000) |
| root of tooth | That part of a tooth below the neck, covered by cementum rather than enamel, and attached by the periodontal ligament to the alveolar bone. Synonym: radix dentis, radix, root. (05 Mar 2000) |
| root planing | A procedure for smoothing of the roughened root surface or cementum of a tooth after subgingival curettage or scaling, as part of periodontal therapy. (12 Dec 1998) |
| root pressure | <botany> Pressure in the roots which, when the shoot is cut off, will cause liquid to ooze from the root stump, the mechanisms and tissues involved in this process are not clearly understood. (09 Oct 1997) |
| root resection | Excision of the apical portion of a tooth through an opening made in the overlying labial, buccal, or palatal alveolar bone. (12 Dec 1998) |
| root resorption | Resorption in which cementum or dentin is lost from the root of a tooth owing to cementoclastic or osteoclastic activity in conditions such as trauma of occlusion or neoplasms. (12 Dec 1998) |