| prostatic sinus | The groove on either side of the urethral crest in the prostatic part of the urethra into which the prostatic ducts open. Synonym: sinus prostaticus. (05 Mar 2000) |
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| prostatic urethra | The prostatic part of the male urethra, about 2.5 cm in length, that traverses the prostate; it includes the seminal colliculus, and the ejaculatory and prostatic ducts open into it. Synonym: pars prostatica urethrae. (05 Mar 2000) |
| prostatic utricle | A minute pouch in the prostate opening on the summit of the seminal colliculus, the analogue of the uterus and vagina in the female, being the remains of the fused caudal ends of the paramesonephric ducts. Synonym: utriculus prostaticus, masculine uterus, Morgagni's sinus, sinus pocularis, uterus masculinus, vagina masculina, vesica prostatica, Weber's organ. (05 Mar 2000) |
| prostatic venous plexus | A venous plexus, arising chiefly from the dorsal vein of the penis, situated below the base of the bladder at the sides of the prostate. See: prostaticovesical plexus. Synonym: plexus venosus prostaticus, plexus pudendalis, Santorini's labyrinth. (05 Mar 2000) |
| Young prostatic tractor | A short, straight tubular instrument with blades at its tip, which can be rotated open and closed; it is passed into the prostatic urethra, through a prostatotomy incision made during the later stages of open perineal prostatectomy, with its tip into the bladder; direct traction on the instrument brings the prostate gland down into the operative field where enucleation can be more easily performed. (05 Mar 2000) |
| 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) |