| 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-cerebrospinal fluid barrier | A barrier located at the tight junctions which surround and connect the cuboidal epithelial cells on the surface of the choroid plexus; capillaries and connective tissue stroma of the choroid do not represent a barrier to protein tracers or dyes. (05 Mar 2000) |
| blood-retinal barrier | Specialised nonfenestrated tightly-joined endothelial cells that form a transport barrier for certain substances between the retinal capillaries and the retinal tissue. (12 Dec 1998) |
| blood-shotten | Red and inflamed; suffused with blood, or having the vessels turgid with blood, as when the conjunctiva is inflamed or irritated. "His eyes were bloodshot, . . . And his hair disheveled." (Dickens) Origin: Blood + shot, p. P. Of shoot to variegate. Source: Websters Dictionary (01 Mar 1998) |
| blood-testis barrier | The membrane in the testis that separates sperm from the bloodstream. (09 Oct 1997) |
| blood-thinner | <haematology, pharmacology> Any substance that prevents blood clotting. Those drugs administered for prophylaxis or treatment of thromboembolic disorders are heparin, which inactivates thrombin and several other clotting factors and which must be administered parenterally and the oral anticoagulants (warfarin, dicumarol and congeners) which inhibit the hepatic synthesis of vitamin K dependent clotting factors. Anticoagulant solutions used for the preservation of stored whole blood and blood fractions are acid citrate dextrose (ACD), citrate phosphate dextrose (CPD), citrate phosphate dextrose adenine (cPDA 1) and heparin. Anticoagulants used to prevent clotting of blood specimens for laboratory analysis are heparin and several substances that make calcium ions unavailable to the clotting process, including EDTA (ethylenediaminetetraacetic acid), citrate, oxalate and fluoride. (18 Nov 1997) |
| blood-vascular system | The heart and the blood vessels by which blood is pumped and circulated through the body. (12 Dec 1998) |
| bloodbird | <zoology> An Australian honeysucker (Myzomela sanguineolata); so called from the bright red colour of the male bird. Source: Websters Dictionary (01 Mar 1998) |
| blooded | Having pure blood, or a large admixture or pure blood; of approved breed; of the best stock. Used also in composition in phrases indicating a particular condition or quality of blood; as, cold-blooded; warm-blooded. Source: Websters Dictionary (01 Mar 1998) |
| bloodflower | <botany> A genus of bulbous plants, natives of Southern Africa, named Haemanthus, of the Amaryllis family. The juice of H. Toxicarius is used by the Hottentots to poison their arrows. Origin: From the colour of the flower. Source: Websters Dictionary (01 Mar 1998) |
| bloodguilty | Guilty of murder or bloodshed. "A bloodguilty life." . Blood"guiltiness, Blood"guiltless. Source: Websters Dictionary (01 Mar 1998) |
| bloodhound | A breed of large and powerful dogs, with long, smooth, and pendulous ears, and remarkable for acuteness of smell. It is employed to recover game or prey which has escaped wounded from a hunter, and for tracking criminals. Formerly it was used for pursuing runaway slaves. Other varieties of dog are often used for the same purpose and go by the same name. The Cuban bloodhound is said to be a variety of the mastiff. Source: Websters Dictionary (01 Mar 1998) |
| bloodily | In a bloody manner; cruelly; with a disposition to shed blood. Source: Websters Dictionary (01 Mar 1998) |
| bloodiness | 1. The state of being bloody. 2. Disposition to shed blood; bloodthirstiness. "All that bloodiness and savage cruelty which was in our nature." (Holland) Source: Websters Dictionary (01 Mar 1998) |
| bloodless | 1. Destitute of blood, or apparently so; as, bloodless cheeks; lifeless; dead. "The bloodless carcass of my Hector sold." (Dryden) 2. Not attended with shedding of blood, or slaughter; as, a bloodless victory. 3. Without spirit or activity. "Thou bloodless remnant of that royal blood !" (Shak) Blood"lessly, Blood"lessness. Origin: AS. Bldleas. Source: Websters Dictionary (01 Mar 1998) |