Select Page

Archives: Dictionary

Meibomian gland

Noun, pl. Meibomaian glands 1. A special kind of sebaceous gland at the rim of the eyelids inside the tarsal plate, responsible for the supply of meibum, an oily substance that prevents evaporation of the eye’s tear film. Meibum prevents tear spillage onto the cheek, trapping tears between the oiled edge and the eyeball, and makes the closed lids airtight. (wikipedia.org) 2. One of the long sebaceous glands of the eyelids that discharge a fatty secretion which lubricates the eyelids. (merriam-webster.com) Syn: tarsal gland Name origin: Named after Mei·bom, Heinrich (1638–1700), German physician. A professor of medicine at Helmstadt, Germany, Meibom accurately described the sebaceous glands of the eyelids in 1666. Although they are now identified with Meibom, the glands had been figured by the Italian anatomist Giulio Casserio (1561–1616) in 1609, and their existence has been known since the time of Galen....

Read More

Meiosis

/mīˈōsəs/ Noun, pl. meioses (Genetics/Cytology) 1. Cell division that produces reproductive cells in sexually reproducing organisms; the nucleus divides into four nuclei each containing half the chromosome number (leading to gametes in animals and spores in plants). (wordnetweb.princeton.edu) 2. A type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores. (Google Dictionary) 3. Cell division of a diploid cell into four haploid cells, which develop to produce gametes. (wiktionary.org 4. Cell division occurring in maturation of sex cells, wherein, over two successive cell divisions, each daughter nucleus receives half the number of chromosomes typical of the somatic cells of the species, so that the gametes are haploid. (Dorland’s Medical Dictionary for Health Consumers) 5. The special process of cell division in sexually reproducing organisms that results in the formation of gametes, consisting of two nuclear divisions in rapid succession that in turn result in the formation of four gametocytes, each containing half the number of chromosomes that is found in somatic cells. (The American Heritage® Medical Dictionary) (Rhetoric) 1. A figure of speech whereby something is made to seem smaller or less important than it actually is. (wiktionary.org) Word origin: From Greek meiosis “a lessening,” from meioun “to lessen,” from meion...

Read More

Meissner’s corpuscle

Noun, pl. Meissner’s corpuscles 1. A type of mechanoreceptor; a type of nerve ending in the skin that is responsible for sensitivity to light touch. In particular, they have highest sensitivity (lowest threshold) when sensing vibrations lower than 50 Hertz. They are rapidly adaptive receptors. (wikipedia.org) 2. Any of the small elliptical tactile end organs in hairless skin containing numerous transversely placed tactile cells and fine flattened nerve terminations. (merriam-webster.com) 3. A sensory nerve ending that is sensitive to mechanical stimuli, found in the dermis in various parts of the body. (Google Dictionary) Syn: Tactile corpuscles, corpuscle of Meissner Name origin: Named after Meissner, Georg (1829–1905), German anatomist and physiologist. Meissner conducted in 1851 intensive comparative microscopic investigations on the fibers and cells of the common trunk of the vestibular and cochlear nerves. In 1852 he studied the tactile corpuscles of the skin which now bear his name. He published other papers dealing with the problems of microscopy, particularly those relating to the skin. In 1857 he published a description of the nerve plexus in the submucosa of the intestinal wall....

Read More

Struggling in Biology?

Are You Premed?

Confused about the MCAT? Not sure how to prepare? This guide will show you how