| root canal treatment | The means by which painful or diseased teeth, in which the pulp is involved, are restored to a healthy state, removal of a normal, diseased, or dead pulp by biochemical and mechanical means, enlargement and sterilization of the root canal, followed by filling the canal, to effect healing of diseased periapical tissues, the diagnosis and treatment of diseases of the pulp and their sequelae. Synonym: endodontic treatment. (05 Mar 2000) |
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| root cap | <botany> A mass of parenchymtous cells which covers and protects the growing cells at the end of a root; a pileorhiza. The issue found at the apex of roots, overlying the root apical meristem and protecting it from friction as the root grows through the soil. Secretes a glycoprotein mucilage as a lubricant. (18 Nov 1997) |
| root caries | Dental caries involving the tooth root, cementum, or cervical area of the tooth. (12 Dec 1998) |
| root caries index | The ratio of the number of teeth with carious lesions of the root, and/or restorations of the root, to the number of teeth with exposed root surfaces. (05 Mar 2000) |
| root cutting | <botany> Part of a root of a woody plant which, under suitable conditions, takes root and forms a new plant. (09 Oct 1997) |
| root dehiscence | A loss of the buccal or lingual bone overlaying the root portion of a tooth, leaving that area covered by soft tissue only. (05 Mar 2000) |
| root end cyst | An inflammatory odontogenic cyst derived histogenetically from Malassez' epithelial rests surrounding the root apex of a nonvital tooth. Synonym: periapical cyst, radicular cyst, root end cyst. (05 Mar 2000) |
| root end granuloma | Chronic nonsuppurative inflammation of periapical tissue resulting from irritation following pulp disease or endodontic treatment. (12 Dec 1998) |
| root filaments | The small, individual fibre fascicles into which the roots of all of the spinal nerves and several cranial nerves (hypoglossus, vagus, oculomotorius) divide in fanlike fashion before entering or leaving the spinal cord or brainstem; the spinal dorsal root may divide into 8 to 12 such rootlets. Synonym: fila radicularia, root filaments. (05 Mar 2000) |
| root foramen | The opening at the apex of the root of a tooth that gives passage to the nerve and blood vessels. Synonym: foramen apicis dentis, apical dental foramen, root foramen. (05 Mar 2000) |
| 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) |
| May apple root | <botany> A powdered mixture of resins taken from dried seeds and root of the mayapple (Podophyllum peltatum), it is typically used as a topical caustic agent. (09 Oct 1997) |
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| medial root of median nerve | <anatomy, nerve> The part of the median nerve coming from the medial cord of the brachial plexus. Synonym: radix medialis nervi mediani. (05 Mar 2000) |
| medial root of optic tract | The smaller division of the posterior end of the optic tract that disappears under the medial geniculate body. Synonym: radix medialis tractus optici. (05 Mar 2000) |
| clinical root | That portion of a tooth embedded in the investing structures; the portion of a tooth not visible in the oral cavity. Synonym: radix clinica. (05 Mar 2000) |
| cochlear root of vestibulocochlear nerve | <anatomy, nerve> One of the components of the vestibulocochlear nerve; it is made up of the central processes of the bipolar neurons which compose the spiral (cochlear) ganglion in the spiral canal of the modiolus of the bony cochlea; the cochlear root enters the cranial cavity by passing in fascicles through the spiral foraminous tract at the bottom of the internal auditory meatus; it enters the brainstem through the pontomedullary groove, closely adhering to the caudoventral aspect of the vestibular root, and distributes its fibres to the ventral and dorsal cochlear nuclei in the floor of the lateral recess of the fourth ventricle. Synonym: radix cochlearis, cochlear root of vestibulocochlear nerve, inferior root of vestibulocochlear nerve, radix inferior nervi vestibulocochlearis. (05 Mar 2000) |
| cochlear root of VIII nerve | <anatomy, nerve> One of the components of the vestibulocochlear nerve; it is made up of the central processes of the bipolar neurons which compose the spiral (cochlear) ganglion in the spiral canal of the modiolus of the bony cochlea; the cochlear root enters the cranial cavity by passing in fascicles through the spiral foraminous tract at the bottom of the internal auditory meatus; it enters the brainstem through the pontomedullary groove, closely adhering to the caudoventral aspect of the vestibular root, and distributes its fibres to the ventral and dorsal cochlear nuclei in the floor of the lateral recess of the fourth ventricle. Synonym: radix cochlearis, cochlear root of vestibulocochlear nerve, inferior root of vestibulocochlear nerve, radix inferior nervi vestibulocochlearis. (05 Mar 2000) |
| motor root | The motor root of a spinal nerve. Synonym: radix anterior, radix motoria, anterior root, motor root, radix ventralis. (05 Mar 2000) |
| motor root of ciliary ganglion | A branch of the oculomotor nerve supplying parasympathetic preganglionic nerve fibres to the ciliary ganglion. Synonym: radix parasympathica ganglii ciliaris, radix oculomotoria ganglii ciliaris, motor root of ciliary ganglion, oculomotor root of ciliary ganglion, radix brevis ganglii ciliaris, short root of ciliary ganglion. (05 Mar 2000) |
| motor root of trigeminal nerve | <anatomy, nerve> The smaller root of the trigeminal nerve, composed of fibres originating from the trigeminal motor nucleus and emerging from the pons medial to the much larger sensory root, to join the mandibular nerve; it carries motor and proprioceptive fibres to the muscles derived from the first bronchial (mandibular) arch, including the four muscles of mastication, plus the mylohyoid, anterior belly of the digastric, and the tensores tympani and veli palati. Synonym: radix motoria nervi trigemini, masticator nerve, portio minor nervi trigemini. (05 Mar 2000) |
| plant root cap | A cone-shaped structure in plants made up of a mass of meristematic cells that covers and protects the tip of a growing root. It is the putative site of gravity sensing in plant roots. (12 Dec 1998) |
| cotton-root bark | Dried root bark of Gossypium herbaceum and other species of Gossypium (family Malvaceae). Has been used as an abortifacient and oxytocic. (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) |
| posterior root | The sensory root of a spinal nerve, having a dorsal root ganglion containing the nerve cell bodies of the fibres conveyed by the root in its distal end. Synonym: radix posterior, radix sensoria, posterior root, radix dorsalis. (05 Mar 2000) |
| Culver's root | <botany> Dried rhizome and roots of Veronicastrum virginicum (family Serophulariaceae). Indigenous to North America. Formerly used as a cathartic. Synonym: black root, Culver's root. (05 Mar 2000) |
| cuticle of root sheath | cuticula vaginae folliculi pili |