- 1. The middle point of a body; loosely, the interior of a body. A c. of any kind, especially an anatomical c.. 2. A group of nerve cells governing a specific function. SYN: centrum [TA]. [L. centrum; G. kentron]- active c. the part of a macromolecule at which a substrate or ligand, upon binding, produces biologic activity; for an enzyme, this is the catalytic c., the site on an enzyme that catalyzes the reaction.- birthing c. a facility, usually in a hospital, that provides labor and delivery services in a comfortable, homelike setting.- Broca c. the posterior part of the inferior frontal gyrus of the left or dominant hemisphere, corresponding approximately to Brodmann area 44; Broca identified this region as an essential component of the motor mechanisms governing articulated speech. SYN: Broca area, Broca field, motor speech c..- catalytic c. active c..- ciliospinal c. the preganglionic motor neurons in the first thoracic segment of the spinal cord which give rise to the sympathetic innervation that eventually influences the dilator muscle of the eye's pupil. SYN: Budge c..- dentary c. a specific ossification c. of the mandible that gives rise to the lower border of its outer plate.- epiotic c. the c. of ossification of the petrous part of the temporal bone that appears posterior to the posterior semicircular canal.- expiratory c. the region of the medulla oblongata that is electrically active during expiration and where electrical stimulation produces sustained expiration.- feeding c. 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.- germinal c. of Flemming the lightly staining c. in a lymphatic nodule in which the predominant cells are large lymphocytes and macrophages. SYN: reaction c..- inspiratory c. the region of the medulla oblongata that is electrically active during inspiration and where electrical stimulation produces sustained inspiration.- Kerckring c. an occasional independent ossification c. in the occipital bone; it appears in the posterior margin of the foramen magnum at about the sixteenth week of gestation. SYN: Kerckring ossicle.- medullary c. SYN: centrum semiovale.- microtubule-organizing c. a locus in interphase and mitotic cells from which most microtubules radiate; in the c. of this c. is the centriole; this c. determines the polarity of cellular microtubules.- ossification c. [TA] the site of earliest bone formation via accumulation of osteoblasts within connective tissue (membranous ossification) or of earliest destruction of cartilage prior to onset of ossification (endochondral ossification). SYN: c. of ossification, ossific c., point of ossification, punctum ossificationis.- primary c. of ossification SYN: primary ossification c.. SYN: centrum ossificationis primarium [TA].- primary ossification c. [TA] this is the first site where bone begins to form in the shaft of a long bone or in the body of an irregular bone. SYN: primary c. of ossification, primary point of ossification, punctum ossificationis primarium.- respiratory c. the region in the medulla oblongata concerned with integrating afferent information to determine the signals to the respiratory muscles; the inspiratory and expiratory centers considered together.- satiety c. a term referring to the region of the ventromedial nucleus in the hypothalamus; destruction of this small region in the rat leads to continuous eating and extreme obesity.- secondary c. of ossification SYN: secondary ossification c.. SYN: centrum ossificationis secundarium [TA].- secondary ossification c. [TA] this is the c. of bone formation appearing later than the punctum ossificationis primarium, usually in epiphysis. SYN: punctum ossificationis secundarium, secondary c. of ossification, secondary point of ossification.- semioval c. SYN: centrum semiovale.- speech centers areas of the cerebral cortex centrally involved in speech function; one is in the left inferior frontal gyrus, a second one in the supramarginal, angular, and first and second temporal gyri. SEE ALSO: Broca c., Wernicke c..- vasomotor c. diffuse area of the reticular formation in the lateral medulla containing neurons that control vascular tone; consists of separate vasodepressor and vasopressor areas.- vital c. c. essential to life; usually refers to the centers located in the medulla oblongata which are necessary for the maintenance of respiration and circulation.- Wernicke c. the region of the cerebral cortex thought to be essential for understanding and formulating coherent, propositional speech; it encompasses a large region of the parietal and temporal lobes near the lateral sulcus of the left cerebral hemisphere; corresponding approximately to Brodmann areas 40, 39, and 22. SYN: sensory speech c., Wernicke area, Wernicke field, Wernicke region, Wernicke zone.
* * *cen·ter or chiefly Brit cen·tre 'sent-ər n a group of nerve cells having a common function <the brain stem's respiratory \center> called also nerve center
* * *cen·ter (senґtər) [L. centrum, from Gr. kentron ] 1. the middle point of a body. 2. a collection of neurons in the central nervous system concerned with performance of a particular function; see also area.
Medical dictionary. 2011.