| nuclear-cytoplasmic ratio | Ratio of volume of nucleus to volume of cytoplasm, fairly constant for a particular cell type and usually increased in malignant neoplasms. (05 Mar 2000) |
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| acoustic vesicle | One of the paired sacs of invaginated ectoderm that develop into the membranous labyrinth of the internal ear. Synonym: acoustic vesicle, otic vesicle. (05 Mar 2000) |
| acrosomal vesicle | A vesicle derived from the Golgi apparatus during spermiogenesis whose limiting membrane adheres to the nuclear envelope; together with the acrosomal granule within, it spreads in a thin layer over the pole of the nucleus to form the acrosomal cap. (05 Mar 2000) |
| allantoic vesicle | The hollow portion of the allantois. (05 Mar 2000) |
| amniocardiac vesicle | The rostral portion of the most primitive intraembryonic celom. (05 Mar 2000) |
| auditory vesicle | One of the paired sacs of invaginated ectoderm that develop into the membranous labyrinth of the internal ear. Synonym: acoustic vesicle, otic vesicle. (05 Mar 2000) |
| Baer's vesicle | An obsolete term for vesicular ovarian follicle. (05 Mar 2000) |
| blastodermic vesicle | In mammalian development, cleavage produces a thin walled hollow sphere, whose wall is the trophoblast, with the embryo proper being represented by a mass of cells at one side. The blastocyst is formed before implantation and is equivalent to the blastula. (18 Nov 1997) |
| gas vesicle | The hollow, cylindrical, gas-filled structure in the gas vacuole. It confers ability for gas vacuole to float. (09 Oct 1997) |
| germinal vesicle | The nucleus of a primary oocyte, the development of which is suspended in prophase I of the first meiotic division between embryohood and sexual maturity. (09 Oct 1997) |
| vesicle | <pathology> A closed membrane shell, derived from membranes either by a physiological process (budding) or mechanically by sonication. Vesicles of dimensions in excess of 50nm are believed to be important in intracellular transport processes. See: coated vesicles. (18 Nov 1997) |
| vesicle hernia | Protrusion of a segment of the bladder through the abdominal wall or into the inguinal canal and into the scrotum. (05 Mar 2000) |
| cerebral vesicle | Each of the three divisions of the early embryonic brain (prosencephalon, mesencephalon, and rhombencephalon). Synonym: encephalic vesicle, primary brain vesicle. (05 Mar 2000) |
| cervical vesicle | An abnormally persisting vestige of the cervical sinus or its associated branchial grooves. (05 Mar 2000) |
| membrane vesicle | <cell biology> Closed unilamellar shells formed from membranes either in physiological transport processes or else when membranes are mechanically disrupted. They form spontaneously when membrane is broken because the free ends of a lipid bilayer are highly unstable. (18 Nov 1997) |