Definitions and descriptions
There are currently 54 terms in this directory beginning with the letter B.
B cell (B SELL)
A subgroup of lymphocytes, including memory B cells and plasma cells, both of which are involved in adaptive immune responses
Bacteria (bak-TEER-ee-yuh) (Sing.— bacterium)
The simple unicellular microorganisms of the class Schizo-mycetes; may be free living, saprophytic, or parasitic
This is a condition in which the squamous epithelium of the esophagus is replaced by metaplastic columnar epithelium containing goblet and columnar cells (specialized intestinal metaplasia). Present in up to 15% of patients with chronic reflux, Barrett esophagus is believed to arise from chronic reflux-induced injury to the esophageal squamous epithelium; however, it is also increased in patients with truncal obesity independent of GERD. Barrett esophagus is suspected at endoscopy from the presence of orange, gastric type epithelium that extends upward more than 1 cm from the gastroesophageal junction into the distal tubular esophagus in a tongue-like or circumferential fashion.
Bartholin’s glands (BAR-toh-linz)
The small glands in the wall of the vagina; secrete mucus into the vagina and vestibule (Syn.—vestibular glands)
Basal ganglia (BAY-zuhl GANG-lee-ah)
Masses of gray matter within the white matter of the cerebral hemispheres; concerned with subconscious aspects of skeletal muscle activity, such as accessory movements
Basal metabolic rate (BAY-zuhl met-ah-BAHL-ik RAYT)
The energy required to maintain the functioning of the body in a resting condition
A hydrogen ion (H +) acceptor, or hydroxyl ion (OH -) donor; when in solution, has a pH greater than 7
Basilar layer (bah-SILL-ar LAY-er)
The permanent vascular layer of the endometrium that is not lost in menstruation; regenerates the functional layer during each menstrual cycle
Benign Prostatic Hyperplasia (BPH)
Benign prostatic hyperplasia is a noncancerous (benign) growth of the prostate gland.
Beta cells (BAY-tah SELLS)
The cells of the islets of Langerhans of the pancreas that secrete the hormone insulin
The process by which the long carbon chain of a fatty acid molecule is broken down into two-carbon acetyl groups to be used in cell respiration; takes place in the liver
The secretion of the liver that is stored in the gallbladder and passes to the duodenum; contains bile salts to emulsify fats; is the fluid in which bilirubin and excess cholesterol are excreted
The bile pigment produced from the heme portion of the hemoglobin of old red blood cells; excreted by the liver in bile
Binary fission (BYE-na-ree FISH-en)
The asexual reproductive process in which one cell divides into two identical new cells
Binocular vision (bye-NOK-yoo-lur VI-zhun)
Normal vision involving the use of both eyes; the ability of the brain to create one image from the slightly different images received from each eye
Removal of a small piece of living tissue for microscopic examination; a diagnostic procedure
The early stage of embryonic development that follows the morula; consists of the outer trophoblast and the internal inner cell mass and blastocele (cavity)
The fluid that circulates in the heart and blood vessels; consists of blood cells and plasma
Blood pressure (BLUHD PRE-shure)
The force exerted by the blood against the walls of the blood vessels; measured in mmHg
Blood–brain barrier (BLUHD BRAYN)
The barrier between the circulating blood and brain tissue, formed by astrocytes and brain capillaries; prevents harmful sub- stances in the blood from damaging brain neurons
- The physical human being as a whole.
- The supporting part of a vertebra.
- The central portion of the sternum.
- Any of a number of small structures, such as the cell body of a neuron or the sensory carotid body
- A connective tissue made of osteocytes in a calcified matrix.
- An organ that is an individual part of the skeleton
A disease, characterized by muscle paralysis, caused by the bacterium Clostridium botulinum
Bowman’s capsule (BOW-manz KAP-suhl)
The expanded end of the renal tubule that encloses a glomerulus; receives filtrate from the glomerulus
The part of the central nervous system within the skull; regulates the activity of the rest of the nervous system
Brain abscess is a focal collection of pus/necrotic tissue with the brain paranchyma, which can arise as a compication of a variety of infections, trauma or surgery. The manifestations of brain abscess depends on the site, size and the immune status of the patient.
Bronchial tree (BRONG-kee-uhl TREE)
The entire system of air passageways formed by the branching of the bronchial tubes within the lungs; the smallest bronchioles terminate in clusters of alveoli
Bronchiectasis is usually established clinically on the basis of chronic daily cough with viscid sputum production, and radiographically by the presence of bronchial wall thickening and luminal dilation on chest x-rays.
Brush border (BRUSH BORE-der)
The collective name for the microvilli of the absorptive cells of the mucosa of the small intestine
Bubonic Plague is the most common, caused by the bite of an infected flea. Y.pestis, enters at the bite and travels through the lymphatic system to the nearest lymph node, replicates itself and causes the lymph node to be inflamed, tense and painful, turning into open sores with pus.
Buffer system (BUFF-er SIS-tem)
A pair of chemicals that prevents significant changes in the pH of a body fluid
Bulbourethral glands (BUHL-boh-yoo-REE-thruhl)
The glands on either side of the prostate gland that open into the urethra; secrete an alkaline fluid that becomes part of semen (Syn.—Cowper’s glands)
Bundle of His (BUN-duhl of HISS)
The third part of the cardiac conduction pathway, located in the upper interventricular septum (Syn.—atrioventricular bundle)
Damage caused by heat, flames, chemicals, or electricity, especially to the skin; classified as first degree (minor), second degree (blisters), or third degree (extensive damage)