Dictionary

Body systems

Anatomy and the conditions of each body system, from the heart and lungs to the skin.

blisterA raised bubble of skin filled with clear fluid.

blood cellAny of the cells carried in the blood: red cells, white cells or platelets.

blood clotA soft, gel-like clump that forms when blood changes from a liquid to a solid.

blood pressureThe force of blood pushing against the walls of the arteries, written as systolic over diastolic in mm Hg.

blood productAny part of donated blood prepared for transfusion, such as red cells, plasma or platelets.

blood transfusionGiving blood, or a part of blood, from a donor into a person's vein.

bloodstreamThe blood flowing through the body's blood vessels.

bloodstream infectionAn infection in which bacteria or fungi are growing in the blood.

body fluidAny liquid made in or found inside the body, such as blood, urine, saliva or fluid inside cells.

body temperatureThe degree of heat of the body, measured with a thermometer as one of the vital signs.

bone densityThe amount of mineral, mostly calcium, packed into a given area of bone, which reflects how strong the bone is.

bone marrowThe soft, spongy tissue inside bones that makes blood cells.

bony prominenceA place where a bone lies close under the skin with little fat or muscle over it, such as the heel or tailbone.

bowelThe intestine: the long tube of the digestive tract from the stomach to the anus.

bowel movementThe passing of stool (feces) from the bowel out through the anus.

bowel obstructionA partial or complete blockage that stops food, fluid and gas from moving through the small or large bowel.

bradycardiaA heart rate slower than normal; in an adult, fewer than 60 beats per minute.

bradykininA small protein in the body that widens blood vessels, makes them leak fluid and causes pain.

bradypneaBreathing that is slower than normal for the person's age.

brain stemThe lowest part of the brain, which connects it to the spinal cord and controls breathing, heart rate and other automatic functions.

brain tumorAn abnormal mass of cells growing in or on the brain, which may be cancerous or not.

Braxton Hicks contractionsIrregular tightening of the uterus during pregnancy that does not open the cervix; sometimes called practice contractions.

breastEither of the two raised areas on the front of the chest; in women they contain glands that make milk.

breast cancerCancer that starts in the cells of the breast.

breast milkThe milk made by the breasts to feed a baby.

breastfeedingFeeding a baby with milk directly from the breast.

breathingMoving air in and out of the lungs.

breathing exerciseA practiced way of breathing used to expand the lungs, move air better or relax.

breech presentationA position of the fetus in which the buttocks or feet, instead of the head, are lowest in the uterus.

Broca areaAn area in the frontal lobe of the brain, usually on the left side, that controls the production of speech.

bronchioleOne of the smallest airways in the lungs, branching from the bronchi and leading to the air sacs.

bronchiolitisInflammation of the bronchioles, the smallest airways in the lungs, most often in babies and young children.

bronchitisInflammation of the bronchi, the large airways that carry air into the lungs.

bronchospasmA sudden tightening of the muscles around the airways that narrows them.

bronchusOne of the large air tubes that branch from the windpipe into each lung.

bruiseA discolored area of skin where blood has leaked from small broken vessels into the tissue underneath.

bruitA whooshing or blowing sound heard with a stethoscope over a blood vessel.

bullaA large blister filled with clear fluid.

bundle of HisA band of special heart fibers that carries the electrical signal from the AV node down to the ventricles.

burnAn injury to the skin or deeper tissues caused by heat, chemicals, electricity, radiation or friction.

buttockOne of the two rounded areas of muscle and fat at the back of the hips that a person sits on.

C. difficileClostridioides difficile, a spore-forming bacterium that can infect the colon (the large intestine).

cachexiaSevere, ongoing loss of muscle and fat, with weakness, that eating more does not fully reverse.

calcitoninA hormone made by the thyroid gland that lowers blood calcium; a lab-made form is used as a drug.

calciumA mineral that builds bones and teeth and that nerves, muscles, the heart and blood clotting need to work.

callusA thick, hard patch of skin formed by repeated rubbing or pressure; also, the new bone that forms as a fracture heals.

calorieA unit that measures the energy in food and the energy the body uses.

candidiasisAn infection caused by Candida, a yeast (a kind of fungus).

caneA walking stick used to give support and balance while walking.

capillaryOne of the tiniest blood vessels, joining the smallest arteries to the smallest veins.