blood-air barrier

barrier /bar·ri·er/ (bar´e-er) an obstruction.

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alveolar-capillary barrier , alveolocapillary barrier see under membrane.

blood-air barrier  alveolocapillary membrane.

blood-aqueous barrier  the physiologic mechanism that prevents exchange of materials between the chambers of the eye and the blood.

blood-brain barrier , blood-cerebral barrier the selective barrier separating the blood from the parenchyma of the central nervous system. Abbreviated BBB.

blood-gas barrier  alveolocapillary membrane.

blood-testis barrier  a barrier separating the blood from the seminiferous tubules, consisting of special junctional complexes between adjacent Sertoli cells near the base of the seminiferous epithelium.

placental barrier  term sometimes used for the placental membrane, because it prevents the passage of some materials between the maternal and fetal blood.

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blood-air barrier

n.

The material intervening between alveolar air and the blood that consists of a nonstructural film or surfactant, alveolar epithelium, basement membrane, and endothelium.

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barrier

an obstruction; a partition between two fluid compartments in the body.

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blood-air barrier

alveolocapillary membrane.

blood-aqueous barrier

the physiological mechanism that prevents exchange of materials between the chambers of the eye and the blood.

blood-brain barrier (BBB)

the barrier separating the blood from the brain parenchyma. See also blood-brain barrier.

blood-CSF barrier

differs from the blood-brain barrier anatomically, in that it consists of the epithelium of the choroid plexuses, but has similar permeabilities.

blood-gas barrier

alveolocapillary membrane.

barrier-retina barrier

endothelium of the retinal capillaries and cells of the retinal pigment epithelium form a nonfenestrated barrier between choroidal tissue fluid and retinal tissue fluid.

blood-synovial barrier

suggested by the presence of plasma proteins of small molecular size and catabolic products of articular cartilage in synovial fluid.

blood-testis barrier

a barrier separating the blood from the seminiferous tubules, consisting of special junctional complexes between adjacent Sertoli cells near the base of the seminiferous epithelium. It provides an extravascular environment which is also adluminal and permits selective nourishment of spermatozoa.

barrier boot

a rubber boot worn by horses to protect the hoof against trauma.

barrier cream

a nonwettable cream used on the skin of the hands and arms to protect against staining and odor absorption when handling offensive materials, e.g. delivery of an emphysematous fetus.

gastric mucosal barrier

the poorly defined mechanism that prevents back diffusion of hydrochloric acid from the stomach into the tissues of the stomach wall.

skin barrier

the protective properties of skin and its relative impenetrability by noxious substances as well as medicaments; usually considered a function of keratinized epithelial cells aided by surface lipids.

barrier teat dip

material which leaves a physical protective coat on the teat between milkings, used mostly to protect against infection for long periods, e.g. during the dry period. Most contain acrylic, latex or collodion.