pale-staining zone
| transverse crest of internal acoustic meatus | A horizontal ridge that divides the fundus of the internal acoustic meatus into a superior and an inferior area. In the former are the introitus of the facial canal and openings for the branches of the vestibular nerve to the utricle and to the ampullae of the anterior and lateral saemicircular canals. In the latter are openings for the cochlear nerve, and for branches of the vestibular nerve to the saccule and to the ampulla of the posterior saemicircular canal. Synonym: crista transversa, falciform crest, transverse crest. (05 Mar 2000) |
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| external acoustic foramen | The orifice of the external acoustic meatus in the tympanic portion of the temporal bone. Synonym: porus acusticus externus, external acoustic foramen, external acoustic pore, external auditory pore, external auditory foramen, orifice of external acoustic meatus. (05 Mar 2000) |
| external acoustic meatus | The passage leading inward through the tympanic portion of the temporal bone, from the auricle to the tympanic membrane; it consists of a bony (inner) portion and a fibrocartilaginous (outer) portion, the cartilaginous external acoustic meatus. Synonym: meatus acusticus externus, acoustic meatus, antrum auris, auditory canal, external auditory meatus. (05 Mar 2000) |
| external acoustic pore | The orifice of the external acoustic meatus in the tympanic portion of the temporal bone. Synonym: porus acusticus externus, external acoustic foramen, external acoustic pore, external auditory pore, external auditory foramen, orifice of external acoustic meatus. (05 Mar 2000) |
| fundus of internal acoustic meatus | The thin cribriform plate of bone separating the cochlea and vestibule from the internal acoustic meatus; a transverse crest divides it into two regions; in the superior region are located the area nervi facialis and the area vestibularis superior; in the inferior region are located the area cochleae, area vestibularis inferior, and foramen singulare. Synonym: fundus meatus acustici interni, fundus of internal auditory meatus. (05 Mar 2000) |
| androgenic zone | A transient adrenocortical zone present in some rodents at birth, most notably in mice, situated between the zona reticularis and the adrenal medulla; it degenerates in males with the secretion at puberty and in females during their first pregnancy; it slowly enlarges in unmated females after puberty and does not degenerate until middle age; the X zone appears to secrete no hormone. Synonym: androgenic zone. Misnomer for the foetal adrenal cortex of primates. Synonym: foetal reticularis. (05 Mar 2000) |
| arcuate zone | The inner third of the basilar membrane of the cochlear duct extending from the tympanic lip of the osseous spiral lamina to the outer pillar cell of the spiral organ (of Corti). Synonym: zona arcuata, zona tecta. (05 Mar 2000) |
| Barnes' zone | The lower fourth of the pregnant uterus, attachment of the placenta to any part of which may cause dangerous haemorrhage. Synonym: cervical zone. (05 Mar 2000) |
| buffer zone | <ecology> An area of land separating two distinct land uses that acts to soften or mitigate the effects of one land use on the other. (09 Oct 1997) |
| capillary zone electrophoresis | A method for separating molecules extremely rapidly based on their electrophoretic mobility. (05 Mar 2000) |
| vascular zone | An area in the external acoustic meatus where a number of minute blood vessels enter from the mastoid bone. Synonym: spongy spot, zona vasculosa. (05 Mar 2000) |
| mantle zone | A layer of small B lymphocytes surrounding the paler-staining germinal centres of lymphoid follicles. (05 Mar 2000) |
| Marchant's zone | The area on the sphenoid and occipital bones at the base of the skull from which the dura mater is readily detached. (05 Mar 2000) |
| marginal zone | The outer, nonnuclear layer of the embryonic neural tube; into its fibrous network grow the longitudinal nerve fibres which eventually become the white matter of the cord and brain stem. Synonym: marginal zone. (05 Mar 2000) |
| vermilion zone | The red margin of the upper and lower lip that commences at the exterior edge of the intraoral labial mucosa ("moist line") and extends outward, terminating at the extraoral labial cutaneous junction; a thinly keratinised type of stratified squamous epithelium deeply penetrated by well-vascularised dermal papillae which show through the translucent epidermis to impart the typical red appearance of the lips. Synonym: vermilion zone, vermilion transitional zone. (05 Mar 2000) |