| division | 1. The act of dividing. 2. <zoology> A rank that if treated as a division of a genus or subgenus is deemed to be of subgeneric rank for the purposes of nomenclature. 3. A taxon at the rank of division. The second highest taxonomic classification for the kingdoms Plantae (plants) and Fungi, between kingdom level and class level. (09 Jan 1998) |
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| division septum | <cell biology> The cell wall that forms between daughter cells at the end of mitosis in plant cells or just before separation in bacteria. (18 Nov 1997) |
| indirect nuclear division | <cell biology> A method of indirect division of a cell, consisting of a complex of various processes, by means of which the two daughter nuclei normally receive identical complements of the number of chromosomes characteristic of the somatic cells of the species. Mitosis, the process by which the body grows and replaces cells, is divided into four phases. 1. Prophase: formation of paired chromosomes, disappearance of nuclear membrane, appearance of the achromatic spindle, formation of polar bodies. 2. Metaphase: arrangement of chromosomes in the equatorial plane of the central spindle to form the monaster. Chromosomes separate into exactly similar halves. 3. Anaphase: the two groups of daughter chromosomes separate and move along the fibres of the central spindle, each toward one of the asters, forming the diaster. 4. Telophase: the daughter chromosomes resolve themselves into a reticulum and the daughter nuclei are formed, the cytoplasm divides, forming two complete daughter cells. NOTE: the term mitosis is used interchangeably with cell division, but strictly speaking it refers to nuclear division, whereas cytokinesis refers to division of the cytoplasm. In some cells, as in many fungi and the fertilized eggs of many insects, nuclear division occurs within the cell unaccompanied by division of the cytoplasm and formation of daughter cells. (13 Nov 1997) |
| equatorial division | Nuclear division in which each chromosome divides equally. (05 Mar 2000) |
| first meiotic division | The first of two consecutive divisions of the nucleus of an eukaryotic cell during the process of meiosis. It includes the following stages of meiosis: prophase I, metaphase I, anaphase I, and telophase I. (09 Oct 1997) |
| ganglionic branches of maxillary nerve | <anatomy, nerve> The ganglionic branches, two short sensory branches of the maxillary nerve in the pterygopalatine fossa, the fibres of which pass through the pterygopalatine ganglion without synapse. Synonym: radix sensoria ganglii pterygopalatini, rami ganglionici nervi maxillaris, rami ganglionares, nervi pterygopalatini, nervi sphenopalatini, pterygopalatine nerves, sensory root of pterygopalatine ganglion. (05 Mar 2000) |
| maxillary | <anatomy> Pertaining to the maxilla. The irregularly shaped bone that with its fellow forms the upper jaw. Origin: L. Maxillaris (18 Nov 1997) |
| maxillary angle | The angle formed by a line drawn from the ophryon and another from the point of the mandible and meeting at the contact between the upper and lower incisor teeth. (05 Mar 2000) |
| maxillary antrum | A air filled cavity within the maxilla (bone that forms the face and upper jaw). The maxillary sinus is located just below the bony prominence of the cheek (27 Sep 1997) |
| maxillary artery | <anatomy, artery> A branch of the external carotid artery which distributes to the deep structures of the face (internal maxillary) and to the side of the face and nose (external maxillary). (12 Dec 1998) |
| maxillary dentition | The teeth supported by the alveolar process of the two maxillae, whether the 10 deciduous teeth or the 16 permanent teeth. Synonym: arcus dentalis superior, maxillary dentition. (05 Mar 2000) |
| maxillary eminence | The bulging lower extremity of the posterior surface of the body of the maxilla, behind the root of the last molar tooth. Synonym: tuber maxillae, eminentia maxillae, maxillary eminence. (05 Mar 2000) |
| maxillary fractures | Fractures of the upper jaw. (12 Dec 1998) |
| maxillary gland | The second largest of the three major salivary glands. It is located deep to the mandible (jaw bone). (12 Dec 1998) |
| maxillary hiatus | The large opening into the maxillary sinus on the nasal surface of the maxilla. Synonym: hiatus maxillaris. (05 Mar 2000) |