| LYDMA | lymphocyte-detected membrane antigen |
|---|---|
| MA | malignant arrhythmia; management and administration; mandelic acid; masseter; Master of Arts; matern... |
| MAC | MacConkey [broth]; major ambulatory category; malignancy-associated changes; maximum allowable conce... |
| MCBM | muscle capillary basement membrane |
| MCG | magnetocardiogram; membrane coating granule; monoclonal gammopathy |
| oral membrane | A bilaminar (ectoderm and endoderm) membrane derived from the prochordal plate; after the embryonic head fold has evolved it lies at the caudal limit of the stomodeum. Synonym: oral membrane, oropharyngeal membrane. (05 Mar 2000) |
|---|---|
| oronasal membrane | A thin, transient epithelial sheet separating the primitive nasal cavity from the stomodeum in the seven-week-old human embryo. Synonym: oronasal membrane. (05 Mar 2000) |
| oropharyngeal membrane | A bilaminar (ectoderm and endoderm) membrane derived from the prochordal plate; after the embryonic head fold has evolved it lies at the caudal limit of the stomodeum. Synonym: oral membrane, oropharyngeal membrane. (05 Mar 2000) |
| otolithic membrane | A gelatinous membrane surmounting the acoustic maculae of the saccule and utricle and containing minute calciferous granules, known as otoconia, otoliths, or statoconia. (12 Dec 1998) |
| outer membrane | The larger of the two membranes of a double membrane. (05 Mar 2000) |
| ovular membrane | The membrane enveloping the yolk; specifically, the thickened cell membrane of large-yolked ova. Synonym: ovular membrane, vitelline membrane. Sometimes used to designate the zona pellucida of a mammalian ovum. Synonym: yolk membrane. (05 Mar 2000) |
| oxygenators, membrane | Devices in which blood and oxygen are separated by a semipermeable membrane, generally of teflon or polypropylene, across which gas exchange occurs. The membrane may be arranged as a series of parallel plates or as a number of hollow fibres; in the latter arrangement, the blood may flow inside the fibres, which are surrounded by gas, or the blood may flow outside the fibres and the gas inside the fibres. (12 Dec 1998) |
| tectorial membrane | A gelatinous membrane, attached to the bony spiral lamina, which overlies the hair cells within the cochlea of the inner ear. (12 Dec 1998) |
| tectorial membrane of cochlear duct | A gelatinous membrane that overlies the spiral organ (Corti) in the inner ear. Synonym: membrana tectoria ductus cochlearis, Corti's membrane, tectorium. (05 Mar 2000) |
| tertiary egg membrane | See: egg membrane. (05 Mar 2000) |
| thyrohyoid membrane | A thin, fibrous, membranous sheet filling the gap between the hyoid bone and the thyroid cartilage. Synonym: membrana thyrohyoidea, membrana hyothyroidea. (05 Mar 2000) |
| egg membrane | The investing envelope of the ovum; a primary egg membrane is produced from ovarian cytoplasm (e.g., a vitelline membrane); a secondary egg membrane is the product of the ovarian follicle (e.g., the zona pellucida); a tertiary egg membrane is secreted by the lining of the oviduct (e.g., a shell). (05 Mar 2000) |
| elastic membrane | A membrane formed of elastic connective tissue, present as fenestrated lamellae in the coats of the arteries and elsewhere. (05 Mar 2000) |
| Toldt's membrane | The anterior layer of the renal fascia. (05 Mar 2000) |
| embryonic membrane | A structure or tissue that develops from the fertilised ovum but does not form part of the embryo proper. Synonym: embryonic membrane, extraembryonic membrane. (05 Mar 2000) |