| primitive pit | The depression in the primitive node that serves to connect the notochordal canal with the surface ectoderm and the yolk sac. These connections are referred to as the neurenteric canal. (05 Mar 2000) |
|---|---|
| primitive reticular cell | A cell with processes making contact with those of other similar cell's to form a cellular network; along with the network of reticular fibres, the reticular cell's form the stroma of bone marrow and lymphatic tissues. (05 Mar 2000) |
| primitive ridge | One of the paired ridge's on either side of the primitive groove. (05 Mar 2000) |
| primitive streak | An ectodermal ridge in the midline at the caudal end of the embryonic disk from which arises the intraembryonic mesoderm; achieved by inward and then lateral migration of cells; in human embryos, it appears on day 15 and gives a cephalocaudal axis to the developing embryo. Synonym: germinal streak. (05 Mar 2000) |
| neuroectodermal tumour, primitive | A malignant brain tumour sharing common features and biologic properties with medulloblastoma. Some pathologists and clinicians use the terms interchangeably: they both can disseminate throughout the nervous system and, in some cases, systemically. most lesions arise from the posterior fossa in children under five years of age. The tumour often produces hydrocephalus and symptoms of increased intracranial pressure. Papilledema is often present. (12 Dec 1998) |
| anterior urethra | The portion of urethra distal to urogenital diaphragm (external sphincter). (05 Mar 2000) |
| bulb of urethra | The expanded posterior part of the corpus spongiosum of the penis lying in the interval between the crura of the penis. Synonym: bulbus penis, bulb of corpus spongiosum, bulb of urethra, bulbus urethrae. (05 Mar 2000) |
| male urethra | A canal about 20 cm in length opening at the extremity of the glans penis; it gives passage to the spermatic fluid as well as the urine. Synonym: urethra masculina, urethra virilis. (05 Mar 2000) |
| glands of the female urethra | Numerous mucous glands in the wall of the female urethra. Synonym: glandulae urethrales femininae, Guerin's glands, paraurethral glands, Skene's glands. (05 Mar 2000) |
| glands of the male urethra | Numerous mucous glands in the wall of the penile urethra. Synonym: glandulae urethrales masculinae, Littre's glands. (05 Mar 2000) |
| penile urethra | The portion of the male urethra, about 15 cm in length, which traverses the corpus spongiosum. Synonym: pars spongiosa urethrae masculinae, pars cavernosa, penile urethra, spongy part of the male urethra. (05 Mar 2000) |
| membranous part of male urethra | The portion of the male urethra, about 1 cm in length, extending from the prostate to the beginning of the urethra in the corpus spongiosum just beyond the bulb. Synonym: pars membranacea urethrae masculinae, membranous urethra. (05 Mar 2000) |
| membranous urethra | The portion of the male urethra, about 1 cm in length, extending from the prostate to the beginning of the urethra in the corpus spongiosum just beyond the bulb. Synonym: pars membranacea urethrae masculinae, membranous urethra. (05 Mar 2000) |
| mucosa of female urethra | The inner mucosal layer of the female urethra. Synonym: tunica mucosa urethrae femininae. (05 Mar 2000) |
| muscular coat of female urethra | Muscular layer of the wall of the female urethra. Synonym: tunica muscularis urethrae femininae. (05 Mar 2000) |