| Merkel cell tumour | A rare malignant cutaneous tumour seen in sun-exposed skin of elderly patients composed of dermal nodules of small round cells with scanty cytoplasm in a trabecular pattern; the tumour cells contain cytoplasmic dense core granules resembling neurosecretory granules seen in Merkel cells. Synonym: primary neuroendocrine carcinoma of the skin, trabecular carcinoma. (05 Mar 2000) |
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| merkel cells | Nondendritic, nonkeratinocytic epithelial clear cells normally found in the epidermis and dermis of mammals and humans. They are believed to be of neuroendocrine origin and function as a specific slowly adapting sensory touch receptor. The merkel cell was first described by friedrich sigmund merkel, german anatomist in 1875. (12 Dec 1998) |
| carcinoma, merkel cell | A carcinoma arising from merkel cells located in the basal layer of the epidermis and occurring most commonly as a primary neuroendocrine carcinoma of the skin. Merkel cells are tactile cells of neuroectodermal origin and histologically show neurosecretory granules. The skin of the head and neck are a common site of merkel cell carcinoma, occurring generally in elderly patients. (12 Dec 1998) |
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| Merkel's tactile cell | A specialised tactile sensory nerve ending in the epidermis, characterised by a terminal cuplike expansion of an intraepidermal axon in contact with the base of a single modified keratinocyte. Synonym: meniscus tactus, Merkel's corpuscle, Merkel's tactile cell, Merkel's tactile disk, tactile disk. (05 Mar 2000) |
| Merkel, Friedrich | <person> German anatomist and physiologist, 1845-1919. See: Merkel cell tumour, Merkel's corpuscle, Merkel's tactile cell, Merkel's tactile disk. (05 Mar 2000) |
| Merkel, Friedrich Sigmund | <person> Was Professor of Anatomy successively at Rostock, Konigsberg and Gottingen. Merkel's Corpuscles - one form of sensory "tactile" nerve ending. Lived: 1845-1919. B. Nuremburg, Apr 5th, 1845, d. May 28th, 1919. (05 Dec 1998) |
| Merkel, Karl | <person> German anatomist and laryngologist, 1812-1876. See: Merkel's filtrum ventriculi, Merkel's fossa, Merkel's muscle. (05 Mar 2000) |
| Merkel's corpuscle | A specialised tactile sensory nerve ending in the epidermis, characterised by a terminal cuplike expansion of an intraepidermal axon in contact with the base of a single modified keratinocyte. Synonym: meniscus tactus, Merkel's corpuscle, Merkel's tactile cell, Merkel's tactile disk, tactile disk. (05 Mar 2000) |
| Merkel's filtrum ventriculi | A groove between the two prominences, in each lateral wall of the vestibule of the larynx, formed by the cuneiform and the arytenoid cartilages. Synonym: Merkel's filtrum ventriculi. (05 Mar 2000) |
| Merkel's fossa | A groove in the posterolateral wall of the vestibule of the larynx between the corniculate and cuneiform cartilages. (05 Mar 2000) |
| Merkel's muscle | <anatomy> A fasciculus from the posterior cricoarytenoid muscle inserted into the inferior horn of the thyroid cartilage. Synonym: musculus ceratocricoideus, Merkel's muscle. (05 Mar 2000) |
| Merkel's tactile disk | A specialised tactile sensory nerve ending in the epidermis, characterised by a terminal cuplike expansion of an intraepidermal axon in contact with the base of a single modified keratinocyte. Synonym: meniscus tactus, Merkel's corpuscle, Merkel's tactile cell, Merkel's tactile disk, tactile disk. (05 Mar 2000) |
| T-cell-rich, B-cell lymphoma | <tumour> A B-cell lymphoma in which more than 90% of the cells are of T-cell origin, masking the large cells that form the neoplastic B-cell component. See: adult T-cell lymphoma. (05 Mar 2000) |
| absorption cell | A small glass chamber with parallel sides, in which absorption spectra of solutions can be obtained. (05 Mar 2000) |
| acid cell | One of the cell's of the gastric glands; it lies upon the basement membrane, covered by the chief cell's, and secretes hydrochloric acid that reaches the lumen of the gland through fine intracellular and intercellular canals (canaliculi). Synonym: acid cell, oxyntic cell. (05 Mar 2000) |
| acidophil cell | A cell whose cytoplasm or its granules stain with acid dyes. (05 Mar 2000) |
| acinar cell | Any secreting cell lining an acinus, especially applied to the cell's of the pancreas that furnish pancreatic juice and enzymes to distinguish them from the cell's of ducts and the islets of Langerhans. Synonym: acinous cell. (05 Mar 2000) |