Glossary of Terms - b

Index

Click on a letter to jump to another subsection or click on "all" for the entire document.

a b c d e f g h i k l m n o p q r s t u v w all

Terms

B cells (B lymphocytes): Lymphocytes which transform into plasma cells and produce antibodies.
Bacterium (plural, bacteria): Any microorganism of the class Schizomycetes; composed of several structures, including a nucleus, cytoplasm and cytoplasmic membrane, cell wall, and capsule. Motile forms may have flagella. Some of these one-celled organisms cause diseases.
Barbiturates: A group of drugs derived from barbituric acid that is used to sedate, to control convulsions, or to induce sleep. Blood and urine tests can determine toxic levels of these compounds. Barbiturates may be habit forming.
Batch testing: A laboratory testing procedure in which one test is done simultaneously on multiple specimens in a "batch analyzer," such as a centrifugal analyzer.
Benign tumor: A tumor which is noncancerous.
Benzodiazepine: A chemical that is often used as the active ingredient in mind-affecting drugs such as tranquilizers. Long term use can result in dependence. Benzodiazepine overdose can be determined through blood or urine tests.
Bi-directional: Refers to communication between an instrument and a computer that allows the computer to send instructions to the instrument and for the instrument to send results back to the computer.
Bicarbonate: Essential for regulating vital functions and one of the important buffers necessary to maintain normal acid-base balance in the body. Body metabolism results in mainly acid production, and neutralizing some of such acids is its constant activity, thus it plays a key role in metabolic acidosis or alkalosis. Bicarbonate may be lost through watery feces, or can decrease when lungs cannot expel carbon dioxide.
Bichromatics: Spectrophotometry which uses a secondary wavelength absorbance reading subtracted from a primary wavelength absorbance reading to obtain a delta absorbance reading (Ad). The delta absorbance is used in conjunction with the calibration data to calculate concentration or activity.
Bilirubin: The orange-yellow pigment of bile, the green fluid that aids in digestion and that is secreted by the liver. Bilirubin is formed mainly by hemoglobin breakdown at the end of red cell life and eventually most of it leaves the body in the feces. Two types are in the blood. Water insoluble or unconjugated bilirubin refers to the pigment before it reaches the liver. In the liver it is converted to the water-soluble or conjugated bilirubin which is excreted into the bile. Blood tests for total bilirubin measure both unconjugated and conjugated bilirubin, and are performed to evaluate jaundice. anemia, various liver diseases (including hepatitis), and impaired bile excretion.
Biochemistry: The chemistry of living organisms and their vital processes.
Biochromatic chemical analyzer: Laboratory instrumentation that provides spectrophotometric-photometric monitoring at two different wavelengths to correct for background color which might interfere with measurement of an analyte.
Biopsy: Excision, for examination, of a small amount of tissue from a living body to determine the presence of disease. Also, the tissue excised is called a biopsy.
Biotechnology: Application of biological science information which can lead to the production of commercial products by biologic processes. These include recombinant DNA techniques, development of monoclonal antibodies, as well as gene splicing.
Brain electrical activity mapping (BEAM): A noninvasive diagnostic technique used to detect certain kinds of epilepsy, head injuries, dyslexia, brain tumors, dementia, and other brain diseases. This procedure utilizes a computer to convert data from brain electrical potentials into colored topographical maps of the brain which are then automatically compared with those of an appropriate control group to indicate the degree of deviation from the norm.
Bronchoscopy: The direct visualization of the trachea and bronchi through a rigid or flexible tube (bronchoscope). The procedure can be used to remove foreign bodies or to obtain a specimen for biopsy or other examination.