| membranous neurocranium | The vault of the embryonic skull which is ossified in membrane. (05 Mar 2000) |
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| membranous ossification | Intramembranous ossification, development of osseous tissue within mesenchymal tissue without prior cartilage formation, such as occurs in the frontal and parietal bones. Synonym: intramembranous ossification. Metaplastic ossification, the formation of irregular foci of bone (sometimes including bone marrow) in various soft structures, such as the muscles, lungs, brain, and other sites where osseous tissue is abnormal. (05 Mar 2000) |
| membranous part of interventricular septum | Part of the fibrous skeleton of the heart which is seen as a small, thin, round or oval nonmuscular area at the superior end of the interventricular septum; it lies just below and is continuous with the portion of the fibrous ring of the aortic valve supporting the anterior and posterior cusps, and with the right fibrous trigone; the atrioventricular bundle of conducting tissue courses along its dorsal margin and bifurcates at its inferior margin into the right and left crura. Synonym: pars membranacea septi interventricularis, membranous septum, septum membranaceum ventriculorum. (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 part of nasal septum | The small portion of the nasal septum anterior to the portion supported by the cartilage of the nasal septum. Synonym: pars membranacea septi nasi, membranous septum. (05 Mar 2000) |
| membranous pharyngitis | Inflammation accompanied by a fibrinous exudate, forming a nondiphtheritic false membrane. (05 Mar 2000) |
| membranous septum | The small portion of the nasal septum anterior to the portion supported by the cartilage of the nasal septum. Synonym: pars membranacea septi nasi, membranous septum. (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) |
| membranous wall of middle ear | The wall formed mainly by the tympanic membrane. Synonym: paries membranaceus cavi tympani, lateral wall of middle ear, membranous wall of middle ear. (05 Mar 2000) |
| membranous wall of trachea | The part of the tracheal wall posteriorly that is not reinforced by tracheal cartilages. Synonym: paries membranaceus tracheae. (05 Mar 2000) |
| common limb of membranous saemicircular ducts | The united, nonampullary ends of the superior and posterior saemicircular ducts. Synonym: crus membranaceum commune ductus saemicircularis, common limb of membranous saemicircular ducts. (05 Mar 2000) |
| simple membranous limb of saemicircular duct | The non-ampullary end of the lateral saemicircular duct that opens independently into the utricle. Synonym: crus membranaceum simplex ductus saemicircularis, simple membranous limb of saemicircular duct. (05 Mar 2000) |
| ampulla | Origin: L. 1. A narrow-necked vessel having two handles and bellying out like a jug. 2. A cruet for the wine and water at Mass. The vase in which the holy oil for chrism, unction, or coronation is kept. 3. <biology> Any membranous bag shaped like a leathern bottle, as the dilated end of a vessel or duct; especially the dilations of the semicircular canals of the ear. Source: Websters Dictionary (01 Mar 1998) |
| ampulla canaliculi lacrimalis | A slight dilation at the angle of the lacrimal canaliculus immediately beyond the lacrimal punctum. Synonym: ampulla canaliculi lacrimalis. (05 Mar 2000) |
| ampulla chyli | A dilated sac at the lower end of the thoracic duct into which the intestinal trunk and two lumbar lymphatic trunks open; it occurs inconstantly and when present is located posterior to the aorta on the anterior aspect of the bodies of the first and second lumbar vertebrae. Synonym: ampulla chyli, chyle cistern, chylocyst, Pecquet's cistern, Pecquet's reservoir, receptaculum chyli, receptaculum pecqueti. (05 Mar 2000) |