| blood | <haematology> Considered a circulating tissue composed of a fluid portion (plasma) with suspended formed elements (red blood cells, white blood cells, platelets). Arterial blood is the means by which oxygen and nutrients are transported to tissues, venous blood is the means by which carbon dioxide and metabolic by-products are transported for excretion. (05 Jan 1998) |
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| blood agar | <cell culture> An agar-based medium which hasbeen enriched with sterilised, defibinated blood (sheep, rabbit or horse). It is used for primary plating andsubculturing, especially to determine bacterial haemolysis. (09 Oct 1997) |
| blood-air barrier | The barrier between capillary blood and alveolar air comprising the alveolar epithelium and capillary endothelium with their adherent basement membranes and epithelial cell cytoplasm. Gaseous exchange occurs across this membrane. (12 Dec 1998) |
| blood albumin | <protein> The serum level of the low molecular protein albumin. Albumin, produced by the liver, plays an important role in maintaining plasma oncotic pressure. Normal serum albumin should be 3.5-5.0 grams per decilitre. Low serum albumin can be found in cases of liver disease and malnutrition. (27 Sep 1997) |
| blood-aqueous barrier | The anatomical mechanism that prevents exchange of materials between the chambers of the eye and the blood. The tight junctions of the nonpigmented epithelium of the ciliary body, the junctions of the iris tissues, and iris blood vessels constitute the blood-aqueous barrier. Lipid-soluble substances such as oxygen and carbon dioxide penetrate the barrier at a high rate. Sodium, larger water-soluble ions, proteins, and other large and medium-sized molecules are restricted. (12 Dec 1998) |
| blood bactericidal activity | Native bactericidal property of blood due to normally occurring antibacterial substances such as beta lysin, leukin, etc. (12 Dec 1998) |
| blood bank | A place, usually a separate part or division of a hospital laboratory or a separtate free-standing facility, in which blood is collected from donors, typed, separated into several components, stored, and/or prepared for transfusion to recipients. (05 Mar 2000) |
| blood banks | Centres for collecting, characterizing and storing human blood. (12 Dec 1998) |
| blood blister | <dermatology> A collection of blood within a skin blister that results from minor skin trauma such as a pinch or crushing injury. (27 Sep 1997) |
| blood-boltered | Having the hair matted with clotted blood. "The blood-boltered Banquo smiles upon me." (Shak) Origin: Blood + Prov. E. Bolter to mat in tufts. Cf. Balter. Source: Websters Dictionary (01 Mar 1998) |
| blood-borne pathogens | Infectious organisms in the blood, of which the predominant medical interest is their contamination of blood-soiled linens, towels, gowns, bandages, other items from individuals in risk categories, needles and other sharp objects, and medical and dental waste, all of which health workers are exposed to. This concept is differentiated from the clinical conditions of bacteraemia, viraemia, and fungaemia where the organism is present in the blood of a patient as the result of a natural infectious process. (12 Dec 1998) |
| blood-brain barrier | <pharmacology, physiology> A protective barrier formed by the blood vessels and glia of the brain. It prevents some substances in the blood from entering brain tissue. The blood vessels of the brain (and the retina) are much more impermeable to large molecules (like antibodies) than blood vessels elsewhere in the body. This has important implications for the ability of the organism to mount an immune response in these tissues, although the basis for the difference in endothelial permeability is not well understood. (16 Dec 1997) |
| blood calculus | An angiolith or concretion of coagulated blood. Synonym: hemic calculus. (05 Mar 2000) |
| blood capillary | A vessel whose wall consists of endothelium and its basement membrane; its diameter, when the capillary is open, is about 8 um; with the electron microscope, fenestrated capillary's and continuous capillary's are distinguished. (05 Mar 2000) |
| blood cast | A cast usually formed in renal tubules, but may occur in bronchioles; consists of inspissated material that includes various elements of blood (i.e., erythrocytes, leukocytes, fibrin, and so on), resulting from bleeding into the glomerulus or tubule, or into the alveolus or bronchiole. (05 Mar 2000) |