Glossary of Terms &
Listed Alphabetically - "B"
Bacteria: single-celled organisms that can exist independently, symbiotically (in cooperation with another organism) or parasitically (dependent upon another organism, sometimes to the detriment of the other organism). Examples of bacteria include acidophilus (found in yogurt), streptococcus the cause of strep throat, and E. coli (a normal intestinal bacteria, as well as a disease-causing agent).
Bainbridge reflex: The increased heart rate that follows increased pressure or distension of the right atrium.
Balance study: a nutritional balance study involves the measurement of the intake of a specific nutrient as well as the elimination of that nutrient in urine, feces, sweat, etc. If intake is greater than loss of a particular nutrient the individual is said to be in "positive balance." If intake is less than loss, an individual is said to be in "negative balance" for the nutrient of interest.
Ball-and-socket joint: A synovial joint in which the rounded surface of one bone moves within the cup-shaped depression or fossa of another bone, as in the shoulder or hip joint. Also called a spheroid joint.
Basal metabolic rate (BMR): The rate of metabolism measured under standard or basal conditions considered to be awake, at rest and fasting)
Bile: a yellow, green fluid made in the liver and stored in the gallbladder. Bile may then pass through the common bile duct into the small intestine where some of its components aid in the digestion of fat.
Bile acids: components of bile, formed by the metabolism of cholesterol. Bile acid deficiency may lead to the formation of cholesterol gallstones, because bile salts (formed from bile acids) are required to dissolve cholesterol in bile so that it may be eliminated via the intestines.
Bioavailable: the portion of a nutrient (or other chemical) that can be absorbed, transported, and utilized physiologically.
Biomarker: a physical, functional, or biochemical indicator (e.g., the presence of a particular metabolite) of a physiological or disease process.
Blood-brain barrier (BBB): A barrier consisting of specialized brain capillaries and astrocytes that prevents the passage of materials from the blood to the cerebrospinal fluid in the brain.
Bone mineral density (BMD): a term used in quantifying the mineralization of bone. The mineral component of bone consists largely of calcium and phosphorus. BMD is possitively associated with bone strength and resistance to fracture. BMD can be determined through a low radiation X-ray technique known as DEXA.
Bone remodeling: the continuous turnover process of bone that includes bone resorption and bone formation. An imbalance in the regulation of bone remodeling's two contrasting events, bone resorption and bone formation, increases the fragility of bone and may lead to osteoporosis.
Buffer: a chemical used to maintain the pH of a system by absorbing hydrogen ions (which would make it more acidic) or absorbing hydroxyl ions (which would make it more alkaline).