List of Common Terms in Pharmacology

A

abortifacient	Substance that induces abortion.
absence seizure	Generalized seizure that does not involve motor convulsions; also referred to as petit mal.
absorption	The uptake of nutrients and drugs from the GI tract.
acetate	Compound that contains acetic acid.
acetylcholine (ACH)	Neurotransmitter of parasympathetic (cholinergic) nerves; stimulates the cholinergic receptor; excitatory neurotransmitter in the basal ganglia.
acetylcholinesterase	An enzyme that inactivates acetylcholine.
acid rebound	Effect in which a great volume of acid is secreted by the stomach in response to the reduced acid environment caused by antacid neutralization.
acidification	Process that alters the pH to less than 7.
acidosis	pH less than 7.45 or a condition in which the tissues have relatively more acid or acid waste than normal; disturbance of acid-base balance; when the pH of the blood is below 7.35.
acquired immunity	Protection from viral reinfection in the form of antibodies produced during an infection (active) or produced after exposure to a vaccine (passive).
acquired immunodeficiency syndrome (AIDS)	Viral induced disease characterized by multiple opportunistic infections as a result of depleted lymphocytes involved in the cell-mediated immune process.
acromegaly	Condition usually in middle-aged adults from hypersecretion of growth hormone.
acute coronary syndrome	Term used to cover any group of clinical symptoms compatible with acute myocardial ischemia.
acute myocardial ischemia	Chest pain due to insufficient blood supply to the heart muscle that results from coronary artery disease.
addiction	A chronic neurobiologic disease in which genetic, psychosocial, and environmental factors induce changes in the individual’s behavior to compulsively use drugs despite the harm that may result.
Addison’s disease	Inadequate secretion of glucocorticoids and mineralocorticoids.
ADH (antidiuretic hormone)	Polypeptide substance synthesized by the hypothalamus and released from the posterior pituitary gland that regulates water balance in the body by altering urine volume at the collecting ducts.
adipose tissue	Tissue containing fat cells; fat.
adrenergic neuronal blocker	Drug that acts at the neuronal nerve endings to reduce the formation or release of NE.
adrenergic receptor	Receptor located on internal organs that responds to norepinephrine and epinephrine.
adsorbent	Substance that has the ability to attach other substances to its surface.
ADT	Alternate-day therapy.
adverse effect	General term for undesirable and potentially harmful drug effect.
afferent nerve	Transmits sensory information from peripheral organs to the brain and spinal cord (central nervous system).
afterload	A measure of the vascular resistance that the left ventricle must overcome in order to eject blood during contraction.
agonist	Drug that attaches to a receptor and initiates an action; drug that binds to a receptor and activates a physiologic response or drug action.
agranulocytosis	Acute condition in which there is a reduction in the number of white blood cells (WBCs), specifically polymorphonuclear cells (granulocytes); condition in which the number of white blood cells, in particular the granulocytes, is less than normal.
akathisia	Continuous body movement in which an individual is restless or constantly paces about.
akinesia	Loss of voluntary muscle movement; restless leg movement.
albuminuria	The presence of the plasma protein albumin in the urine.
aldosterone	Hormone released from adrenal cortex that causes the retention of sodium from the kidneys.
alkalosis	pH greater than 7.45 or a condition in which the tissues have less acid than normal; disturbance of acid-base balance; when the pH of the blood is above 7.5.
alkylation	Irreversible chemical bond that some cancer drugs form with nucleic acids and DNA.
allergen	A substance capable of producing an allergic reaction.
alopecia	Baldness or hair loss.
alpha adrenergic drug	Drug that stimulates the alpha adrenergic receptors.
alpha-1 adrenergic blocker	Drug that blocks the alpha-1 effects of NE and EPI.
alpha-1 adrenergic receptor	Receptor located on smooth muscle that mediates smooth muscle contraction.
alpha-2 adrenergic receptor	Receptor located on adrenergic nerve endings that reduces the release of NE.
amenorrhea	Condition in which monthly menstruation (menses) no longer occurs.
amide local anesthetic	Anesthetic class that includes lidocaine, bupivicaine, and mepivicaine and has a moderate to long duration of action because metabolism occurs in the liver.
amylin	Peptide of 37 amino acids that is secreted by the pancreas beta cells along with insulin in response to increasing blood glucose levels.
anabolism	Process that converts or incorporates nutritional substances into tissue; usually associated with conversion of proteins into muscle mass.
analgesia	Decreased response to pain; condition in which painful stimuli are not consciously interpreted (perceived) as hurting; relief from pain; inhibition of the perception of pain.
analgesic	Substance (synthetic or naturally occurring) that inhibits the body’s reaction to painful stimuli or perception of pain.
anaphylaxis	Condition in which the body develops a severe allergic response; this is a medical emergency.
androgen	Male sex hormone responsible for the development of male characteristics.
anemia	Condition in which the number of red blood cells or the amount of hemoglobin (the oxygen-carrying substance) inside the red blood cells is less than normal; condition in which the oxygen-carrying function of the red blood cells to the tissues is decreased.
aneurysm	An abnormal widening or ballooning of a portion of an artery due to weakness in the wall of the blood vessel.
angina	Chest pain or discomfort that occurs when the heart muscle does not get enough blood and oxygen.
angina pectoris	Chest pain due to decreased blood flow (ischemia) to the heart; caused by insufficient blood flow to the heart.
angioedema	Edema and swelling beneath the skin.
angiotensin-converting enzyme inhibitor (ACE)	Treat high blood pressure and other conditions.
(ACEI)	Drug that inhibits the enzymatic conversion of angiotensin I to angiotensin II.
angiotensin receptor blocker (ARB)	Drug that blocks the receptors for angiotensin II.
angiotensin II	Potent vasoconstrictor that also stimulates release of aldosterone and antidiuretic hormone.
anion	Negatively charged ion.
antacid	Drug that neutralizes hydrochloric acid (HCl) secreted by the stomach.
antagonist	Drug that attaches to a receptor, does not initiate an action, but blocks an agonist from producing an effect; drug that binds to a receptor and interferes with other drugs or substances from producing a drug effect.
antagonistic	Counteract; oppose.
antiallergic	Drug that prevents mast cells from releasing histamine and other vasoactive substances.
antianxiety drug	Drug used to treat anxiety; these drugs are also referred to as anxiolytics.
antiarrhythmic drug	Drug used to restore normal cardiac rhythm.
anti-atherogenic	The ability to prevent or stop atherosclerosis, the deposition of lipid-containing plaques on the innermost layers of the arteries.
antibacterial spectrum	Bacteria that are susceptible to the antibacterial actions of a particular drug.
antibiotic	Antibacterial drug obtained from other microorganisms.
antibiotic susceptibility	Identification of the antibiotics, by bacterial culture and sensitivity testing, that will be effective against specific bacteria.
antibody	A specialized protein (immunoglobulin) that recognizes the antigen that triggered its production; a protein (immunoglobulin) produced naturally or induced by a foreign protein that provides immune protection against infectious organisms and foreign substances; normally produced when a foreign substance such as a pathogen enters the body.
anticholinergic	Refers to drugs or effects that reduce the activity of the parasympathetic nervous system.
anticonvulsant	Drug usually administered IV that stops a convulsive seizure.
antidiuretic hormone (ADH)	Polypeptide substance synthesized by the hypothalamus and released from the posterior pituitary gland that regulates water balance in the body by altering urine volume at the collecting ducts; hormone from the posterior pituitary gland that causes retention of water from the kidneys; substance produced in the hypothalamus and secreted by the pituitary gland that modulates urine production and allows the kidneys to reabsorb water in order to conserve body water.
antiepileptic drug	Drug usually administered orally to prevent epileptic seizures.
antilipemic drug	A drug that reduces the level of fats in the blood.
antigen	Substance, usually protein or carbohydrate, that is capable of stimulating an immune response; any substance that stimulates an immune response, i.e., production of an antibody.
antigenic drift and antigenic shift	The ability of viruses to change the composition or structure of their surface proteins (viral coat) that are responsible for producing disease (pathogenicity).
antihistaminic	Drug that blocks the action of histamine at the target organ.
antiinflammatory	Minimizing or stopping the response to tissue injury by reducing the pain, localized swelling, and chemical substances released at the site of injury.
antimetabolite	A drug that is very similar to natural chemicals in a normal biochemical reaction in cells but different enough to interfere with the normal division and functions of cells; drug whose chemical structure is similar to that of normal body metabolites and that inhibits normal cell function.
antimicrobial	Antibacterial drugs obtained by chemical synthesis and not from other microorganisms.
antineoplastic	Drug that inhibits the growth and proliferation of cancer cells.
antipsychotic drug	Drug used to treat schizophrenia and other psychotic conditions.
antipyresis	Reducing an elevated body temperature.
antisecretory	Substance that inhibits secretion of digestive enzymes, hormones, or acid.
antiseptic	Substance that inhibits the growth of microorganisms on living tissue.
antitussive	A drug that suppresses coughing.
anuria	Condition in which no urine is produced.
anxiety	A state of anxiousness and hyperemotionalism that occurs with uncertainty, stress, and fearful situations.
aphthous ulcer	A painful open sore in the mouth or upper throat; also known as a canker sore.
aplastic anemia	Anemia caused by defective functioning of the blood-forming organs (bone marrow).
apoprotein	A protein that is attached to a second molecule that is not a protein.
apoptosis	Cell death, due to either programmed cell death or other physiological events.
aquaporins	Specialized proteins that form pores (channels) in the cell membrane that allow water to pass through but not small molecules like ions.
aquaresis	Renal excretion of water without electrolytes.
aqueous humor	Ocular fluid; watery substance that is located behind the cornea of the eye and in front of the lens.
argyria	Permanent black discoloration of skin and mucous membranes caused by prolonged use of silver protein solutions.
arrhythmia	Disorder of cardiac conduction and electrical impulse formation.
arteriosclerosis	Hardening or fibrosis of the arteries; accumulation of fatty deposits in the walls of arteries.
arthralgia	Joint pain.
arthritis	Inflammation of the joints.
ascites	Excess fluid in the space between the tissues lining the abdomen and abdominal organs (the peritoneal cavity), usually associated with organ failure.
asthma	Inflammation of the bronchioles associated with constriction of smooth muscle, wheezing, and edema; respiratory disease characterized by bronchoconstriction, shortness of breath, and wheezing.
asymptomatic	Condition in which there is no outward evidence (symptom) that an infection is present.
atherogenic	The ability to start or accelerate the deposition of fats and calcium in the walls of arteries, called atherosclerosis.
atherosclerosis	Fatty degeneration of arteries due to accumulation of cholesterol plaques; accumulation of fatty deposits in the walls of arteries.
atonic seizure	Generalized-type seizure characterized by a sudden loss of muscle tone.
autoantibody	An antibody produced by the immune system against one’s own cells; antibodies normally are produced when a foreign substance such as a pathogen enters the body.
autoimmune disease	Condition in which an individual’s tissues are damaged by his or her own immune mechanisms.
automatism	Drug-induced confusion that can cause increased drug consumption.
autonomic nervous system (ANS)	System of nerves that innervate smooth and cardiac muscle (involuntary) of the internal organs and glands.
AV	Atrioventricular, as in the AV node.
avitaminosis	Chronic or long-term vitamin deficiency caused by lack in diet or defect in metabolic conversion in body resulting in a vitamin-specific condition such as beri-beri.

B

bacteria	Single-celled microorganisms, some of which cause disease.
bacterial resistance	Ability of some bacteria to resist the actions of antibiotics.
bactericidal	Antibiotic that kills bacteria; chemical that kills or destroys bacteria.
bacteriostatic	Chemical that inhibits growth or reproduction of bacteria but does not kill bacteria; antibiotic that inhibits the growth of, but does not kill, bacteria.
barbiturate	CNS depressant drug possessing the barbituric acid ring structure.
basal ganglia	A group of cell bodies (gray matter) within the white matter of the cerebrum that helps control body movement; involved in regulation of skeletal muscle tone and body movement.
benzodiazepine	Class of drugs used to treat anxiety and sleep disorders.
beta-lactamases	Bacterial enzymes that inactivate betalactam antibiotics; bacterial enzymes that inactivate penicillin and cephalosporin antibiotics.
beta-1 adrenergic receptor	Receptor located on the heart that increases heart rate and force of contraction.
beta-2 adrenergic receptor	Receptor located on smooth muscle that relaxes smooth muscle when stimulated.
bioavailability	Percentage of the drug dosage that is absorbed.
biphasic	Two different amounts of estrogen hormone are released during the cycle.
bipolar mood disorder	Mood disorder where episodes of mania and depression occur alternately.
black box warning (boxed warning)	A warning that appears in the instructions for use surrounded by a thick black box to alert medical professionals to serious or life-threatening adverse effects associated with the drug usage.
blood pressure (BP)	The pressure of the blood within the arteries; depends primarily on the cardiac output and the peripheral resistance.
bone density	A quantitative measurement of the mineral content of bone; used as an indicator of the structural strength of the bone.
bone mass	A measure of the amount of minerals (mostly calcium and phosphorus) contained in a certain volume of bone.
bone mineral density	Amount of calcium and phosphorus deposited in bone matrix.
bradykinesia	Slowed body movements.
broad-spectrum	Drug that is effective against a wide variety of both gram-positive and gram-negative pathogenic bacteria.
bronchodilator	Drug that relaxes bronchial smooth muscle and dilates the lower respiratory passages.
buccal absorption	Absorption of drug through the mucous membranes lining the oral cavity.

C

CAD (coronary artery disease)	Narrowing of small arteries that supply blood and oxygen to the heart.
calorigenic	Producing heat.
cancer	Disease that involves the development and reproduction of abnormal cells.
candidemia	Infection in the blood caused by the yeast Candida.
candidiasis	Infection caused by the yeast Candida; also known as moniliasis.
cannabinoid	Pharmacologically active substance obtained from the marijuana plant.
carcinogenic	Causing cancer.
carcinoid tumor	A slow-growing type of cancer that can arise in the gastrointestinal tract, lungs, ovaries, and testes.
cardiac arrhythmia	Variation in the normal rhythm (motion) of the heart.
cardiac glycoside	Drug obtained from plants of the genus Digitalis.
cardiac output (CO)	The amount of blood pumped per minute by the heart.
catabolism	Process in which complex compounds are broken down into simpler molecules; usually associated with energy release.
catecholamine	Refers to norepinephrine, epinephrine, and other sympathomimetic compounds that possess the catechol structure.
cathartic	Pharmacological substance that stimulates defecation.
cation	Positively charged ion.
caudal anesthesia	Injection of a local anesthetic into the caudal or subcaudal spinal canal.
cell-cycle nonspecific (CCNS)	Refers to cancer drugs that act in all phases of the cell cycle.
cell-cycle specific (CCS)	Refers to cancer drugs that only act when the cell is actively dividing.
centrally acting skeletal muscle relaxant	Drug that inhibits skeletal muscle contraction by blocking conduction within the spinal cord.
cephalosporinases	Bacterial enzymes that inactivate cephalosporin antibiotics.
CERA	Stands for continuous erythropoietin receptor activator.
cerebellum	Part of the brain that coordinates body movements and posture and helps maintain body equilibrium.
cerebral cortex	Uppermost layers of the cerebrum involved in sensory perception, voluntary motor control, and all higher intellectual abilities.
cerebrum	Largest and uppermost part of the brain that is divided into right and left cerebral hemispheres.
chelate	Chemical action of a substance to bond permanently to a metal ion.
chemical mediator	Substance released from mast cells and white blood cells during inflammatory and allergic reactions.
chemical name	Name that defines the chemical composition of a drug.
chemoprophylaxis	Use of antibiotics to prevent infection, usually before a surgical procedure or in patients at risk for infection.
chemotherapy	Use of drugs to inhibit the growth of or to destroy infectious organisms or cancer cells; use of drugs to kill or inhibit the growth of infectious organisms or cancer cells.
chloride channel activators	A novel class of drugs that stimulate pore-forming receptors in the intestine, causing chloride ions to cross membranes.
cholesterol	A fat (lipid) normally synthesized by the liver; essential for the structure and function of cells.
cholinergic	Refers to the nerves and receptors of the parasympathetic nervous system; also refers to the drugs that stimulate this system.
cholinergic receptor	Receptor located on internal organs and glands that responds to acetylcholine.
-chromic	Suffix meaning color.
chronic	Condition of long duration, usually months or years.
chronic bronchitis	Respiratory condition caused by chronic irritation that increases secretion of mucus and causes degeneration of the respiratory lining.
chronic heart failure (CHF)	Heart disease caused by weakness of the contractile force of the myocardium; condition in which the heart is unable to pump sufficient blood to the tissues of the body.
chylomicron	One of the microscopic particles of emulsified fat found in the blood and lymph and formed during the digestion of fats.
chyme	Partially digested food and gastric secretions that moves into the duodenum from the stomach by peristalsis.
-cidal	Suffix denoting killing, as of microorganisms.
cinchonism	Pattern of characteristic symptoms (central nervous system [CNS] stimulation and headache) associated with the use of cinchona alkaloids (chemicals extracted from the bark of the cinchona tree); quinidine toxicity, which is characterized by ringing in the ears (tinnitus), dizziness, and headache.
circadian rhythm	Internal biological clock; a repeatable 24-hour cycle of physiological activity.
clonic	Convulsive muscle contraction in which rigidity and relaxation alternate in rapid succession.
coagulation	Process by which the blood changes from a liquid to a solid “plug” as a reaction to local tissue injury; normal blood clot formation.
cold sterilization	Destruction of microorganisms at room temperature without the use of heat or ionizing radiation.
conduction system	Specialized cardiac tissue that transmits electrical impulses and regulates the activity of the heart.
constipation	A decrease in stool frequency.
contraception	Preventing pregnancy by preventing either conception (joining of egg and sperm) or implantation in the uterus.
contraindications	Situations or conditions when a certain drug should not be administered.
controlled substance	Drug that has the potential for abuse and thus is regulated by law.
convoluted	Coiled or folded back on itself.
convulsion	Involuntary muscle contraction that is either tonic or clonic.
COPD	Chronic obstructive pulmonary disease, usually caused by emphysema and chronic bronchitis.
coronary artery	Artery that supplies blood flow to the heart.
coronary artery disease (CAD)	Disease of the coronary arteries that decreases blood flow to the heart; narrowing of small arteries that supply blood and oxygen to the heart; condition due to atherosclerosis and insufficient blood flow to the heart.
COX	Cyclooxygenase, a family of enzymes that produce prostaglandins.
C-reactive protein (CRP)	A protein produced by the liver but only found in the blood in conditions of acute inflammation; an inflammation marker.
creatinine	A metabolite of muscle metabolism that is excreted in the urine in proportion to renal function.
creatinine clearance	A measure of renal creatinine excretion that is used to evaluate renal function.
cretinism	Condition in which the development of the body and the brain has been inhibited due to congenital hypothyroidism.
cross-tolerance	Drug tolerance that develops between similarly acting drugs.
CRP (C-reactive protein)	A protein produced by the liver but only found in the blood in conditions of acute inflammation; an inflammation marker.
cryoanesthesia	Removing the sensation of touch or pain by applying extreme cold to the nerve endings.
Cushing’s disease	Excess secretion of adenocorticotropic hormone (ACTH).
cutaneous	Pertaining to the skin.
-cytic	Suffix meaning cells.

D

DCT (distal convoluted tubule)	Part of the nephron that is closest to the collecting duct.
decimal	Another way to write a fraction when the denominator is 10, 100, 1000, and so on.
decubitis ulcer	Bedsore.
deep vein thrombosis (DVT)	A blood clot that forms in a vein deep inside the body.
defecation	Process of discharging the contents of the intestines as feces.
dehiscence	Bursting open or separation of a wound, usually along sutured line.
denaturing	Causing destruction of bacterial protein function; also adulteration of alcohol, rendering it unfit for drinking.
dendritic cell	An antigen-presenting white blood cell that is found in the skin, mucosa, and lymphoid tissues and that initiates a primary immune response.
denominator	Bottom number of a fraction; shows the number of parts in a whole.
dependency	Requirement of repeated drug consumption in order to prevent onset of withdrawal symptoms.
depolarization	The decrease in electric potential across a cell membrane that results in excitation and generation of an action potential.
depolarizing blocker	Produces paralysis by first causing nerve transmission, followed by inhibition of nerve transmission.
depression	Mental state characterized by depressed mood, with feelings of frustration and hopelessness.
dermatitis	Inflammatory condition of the skin associated with itching, burning, and edematous vesicular formations.
dermatophytic	Infection of the skin, hair, or nails caused by a fungus.
designer drug	Chemically altered form of an approved drug that produces similar effects and that is sold illegally.
diabetes insipidus	Chronic condition caused by inadequate secretion of antidiuretic hormone (ADH), in which individuals are extremely thirsty and produce very large amounts of pale urine.
diabetic neuropathy	Nerve disorders caused by diabetes resulting in numbness, pain, and weakness in hands and feet.
diarrhea	Abnormal looseness of the stool or watery stool, which may be accompanied by a change in stool frequency or volume.
digestion	Mechanical and chemical breakdown of foods into smaller units.
digitalization	Method of dosage with cardiac glycosides that rapidly produces effective drug levels.
diplopia	Condition in which a single object is seen (perceived) as two objects; double vision.
disinfectant	Substance that kills disease-causing microorganisms on nonliving surfaces.
dissociative anesthesia	Form of general anesthesia in which patients do not appear to be unconscious.
distal convoluted tubule (DCT)	Part of the nephron that is closest to the collecting duct.
disulfiram-like reaction	Reaction to alcohol ingestion characterized by intense nausea as a result of drug-induced accumulation of acetaldehyde, similar to that produced by disulfiram (Antabuse).
diuresis	Condition that causes urine to be excreted; usually associated with large volumes of urine.
DM	Diabetes mellitus.
dopamine	Inhibitory neurotransmitter in the basal ganglia.
dose	A measurement of the amount of drug that is administered.
drug	Chemical substance that produces a change in body function.
drug absorption	Entrance of a drug into the bloodstream from its site of administration.
drug addiction	Condition of drug abuse and drug dependence that is characterized by compulsive drug behavior.
drug compliance	Following drug prescription directions exactly as written.
drug dependence	Condition of reliance on the use of a particular drug, characterized as physical and/or psychological dependence.
drug distribution	Passage of a drug from the blood to the tissues and organs of the body.
drug excretion	Elimination of the drug from the body.
drug indications	Intended or indicated uses for any drug.
drug metabolism	The enzymatic biotransformation of a drug into metabolites.
drug microsomal metabolizing system (DMMS)	Group of enzymes located primarily in the liver thatfunction to metabolize (biotransformation) drugs.
drug resistance	Lack of responsiveness of cancer cells to chemotherapy.
drug tolerance	Requirement of larger doses to be consumed in order to obtain the desired effects; decreased drug effect occurring after repeated drug administration.
ductless glands	Containing no duct; endocrine glands that secrete hormones directly into the blood or lymph without going through a duct.
DVT (deep vein thrombosis)	A blood clot that forms in a vein deep inside the body.
dwarfism	Inadequate secretion of growth hormone during childhood, characterized by abnormally short stature and normal body proportions.
dysentery	Condition characterized by frequent watery stools (usually containing blood and mucus), tenesmus, fever, and dehydration.
dysgeusia	A persistent abnormal sense of taste.
dyskinesia	Distortion in voluntary muscle movement, spastic; uncontrollable, abnormal involuntary repetitive body movements.
dysmenorrhea	Difficult or painful menstruation; condition that is associated with painful and difficult menstruation.
dyspepsia	Indigestion.
dysphoria	Feeling of discomfort or unpleasantness.
dystonia	Muscle spasms, facial grimacing, and other involuntary movements and postures.
dystonic reaction	Reaction characterized by muscle spasms, twitching, facial grimacing, or torticollis.

E

ECL (enterochromaffin-like cells)	Cells that synthesize and release histamine.
ectopic beat	Extra heartbeat, a type of cardiac arrhythmia.
ectopic focus	Area of the heart from which abnormal impulses originate.
eczematoid dermatitis	Condition in which lesions on the skin ooze and develop scaly crusts.
edema	Swelling caused by fluid in body tissue.
ED50	Effective dose 50, or dose that will produce an effect that is half of the maximal response.
efferent nerve	Carries the appropriate motor response from the brain and spinal cord to the peripheral organs.
electrocardiogram (ECG)	Recording of the electrical activity of the heart.
electroencephalogram (EEG)	A surface recording of the electrical activity of the brain.
electrolyte	Ion in solution, such as sodium, potassium, or chloride, that is capable of mediating conduction (passing impulses in the tissues); dissolved mineral that can conduct an electrical current and that exists as an ion.
emesis	Vomiting.
emetogenic	A substance that causes vomiting.
emollient	Substance that is soothing to mucous membranes or skin.
emphysema	Disease process causing destruction of the walls of the alveoli.
endemic	Present continually in a particular geographic region, often in spite of control measures.
endocrine	Pertaining to glands that secrete substances directly into the blood.
endocytosis	Process by which cells absorb molecules (such as proteins) from outside the cell by engulfing them with their cell membrane.
endogenous	Naturally occurring within the body; originating or produced within an organism, tissue, or cell.
endometrium	Lining of the uterus.
endorphins	Neuropeptides produced within the CNS that interact with opioid receptors to produce analgesia.
enteric-coated	Type of tablet or pill with a coating that enables it to pass through the stomach without being dissolved, so the stomach lining will not be irritated; the drug is then released in the intestine.
enterochromaffin-like cells (ECL)	Cells that synthesize and release histamine.
enterohepatic recycling	The process whereby drug is eliminated from the liver/biliary tract into the GI tract and then reabsorbed from the GI tract back to the liver.
enzyme induction	Increase in the amount of drugmetabolizing enzymes after repeated administration of certain drugs.
enzyme inhibition	Inhibition of drug-metabolizing enzymes by certain drugs.
epidural anesthesia	Injection of a local anesthetic into the extradural (outermost part of the spinal canal) space.
epilepsy	CNS disorder characterized by uncontrolled nerve cell discharges and manifested by recurring, spontaneous seizures of any type.
epinephrine (EPI)	Hormone from adrenal medulla that stimulates adrenergic receptors, especially during stress.
equipotent	When drugs (substances) produce the same intensity or spectrum of activity; usually, the absolute amount of drug (for example, 5, 10 mg) that produces the response is different for each substance, but the response generated is the same.
erythema	Redness of the skin, often a result of capillary dilation; abnormal redness of the skin, caused by capillary congestion.
erythropoiesis	Process through which red blood cells are produced.
ESA	Stands for erythropoietin stimulating agent.
eschar	Thick crust or scab that develops after skin is burned.
essential amino acids and fatty acids	Substances that are required for critical body function to sustain life and are not produced by the body.
essential hypertension	Major form of hypertension for which the cause is unknown.
ester local anesthetic	Anesthetic class that includes procaine, cocaine, benzocaine, and tetracaine; metabolism is primarily by plasma cholinesterases.
euphoria	Feeling of well-being or elation; feeling good.
euthyroid	Having normal thyroid gland function.
euvolemia	State of normal body fluid volume.
evacuation	Process of removal of waste material from the bowel.
excoriation	An abrasion of the epidermis (skin) usually from a mechanical (not chemical) cause; a scratch.
exertional angina	Angina pectoris caused by increased physical exertion.
exocytosis	The discharge of substances contained in vesicles by fusion of the vesicular membrane with the outer cell membrane.
exogenous	Originating or produced outside the organism or body; originating outside the body, or administered into the body from outside.
exogenous, or reactive, depression	Depression caused by external factors or life events.
exophthalmos	Protruding eyeballs out of the socket.
expectorant	Substance that causes the removal (expulsion) of mucous secretions from the respiratory system; drug that helps clear the lungs of respiratory secretions.
expectorate	Eject from the mouth; spit.
extracellular	Area outside the cell.
extrapyramidal syndrome (EPS)	Movement disorders such as akathisia, dystonia, and parkinsonism caused by antipsychotic drug therapy.

F

false transmitter	Substance formed in nerve endings that mimics and interferes with the actions of the normal transmitter.
fasciculation	Twitchings of muscle fiber groups.
fertility drug	Drug that stimulates ovulation.
fibrocystic breast disease	Condition in which cystic lesions form within the connective tissue of the breasts.
fight or flight reaction	Response of the body to intense stress; caused by activation of the sympathetic division of the ANS.
first-pass metabolism	Drug metabolism that occurs in the intestines and liver during oral absorption of drugs into the systemic circulation.
flashback	Phenomenon occurring long after the use of LSD in which the hallucinogenic effects are relived in some type of memory flash.
foam cells	A type of cell formed after macrophages in the artery wall digest LDL cholesterol; a transformed macrophage.
fraction	Part of a whole.
FSH	Follicle stimulating hormone. In the female stimulates the development of the follicles, and in the male stimulates spermatogenesis.
fungicidal	Substance, chemical solution, or drug that kills fungi; chemical that kills or destroys fungi.
fungistatic	Inhibits the growth of fungi but does not kill off the fungi; chemical that inhibits growth or reproduction of fungi but does not kill fungi.
fungus (fungi)	A group of microorganisms with a membrane-bound nucleus that includes yeasts and molds.

G

GABA	Gamma-aminobutyric acid, an inhibitory neurotransmitter in the CNS.
gametocyte	Organism in an immature stage of development.
ganglionic blocker	Drug that blocks the nicotinic-neural (Nn) receptors and reduces the activity of the autonomic nervous system.
ganglionic stimulant	Drug that stimulates the nicotinicneural (Nn) receptors to increase autonomic nervous system activity.
gastric lavage	Flushing of the stomach.
gastroparesis	Condition, also called delayed gastric emptying, in which the stomach muscles do not function properly.
general anesthesia	Deep state of unconsciousness in which there is no response to stimuli, including painful stimuli.
general anesthetic	Drug that abolishes the response to pain by depressing the central nervous system (CNS) and producing loss of consciousness.
generalized seizure	Seizure originating and involving both cerebral hemispheres that may be either convulsive or nonconvulsive.
generic name	Nonproprietary name of a drug.
GERD	Gastroesophageal reflux disease.
geriatrics	Medical specialty that deals with individuals over 65 years of age.
germ cells	Cells that become the reproductive cells eggs (in ovary) or sperm (in testes).
germicidal	Substance, chemical solution, or drug that kills microorganisms.
gigantism	Increased secretion of growth hormone in childhood, causing excessive growth and height.
GIP	Glucose-dependent insulinotropic peptide, also known as gastric inhibitory peptide.
GLP-1	Glucagon-like peptide-1.
glucagon	Hormone released by the alpha cells of the pancreas to increase plasma glucose concentration.
glucocorticoid	Steroid produced within the adrenal cortex (or a synthetic drug) that directly influences carbohydrate metabolism and inhibits the inflammatory process.
gluconeogenesis	The synthesis of glucose from molecules that are not carbohydrates, such as amino and fatty acids or glycerol.
GLUT	Glucose transport proteins.
glycated hemoglobin	Form of hemoglobin that is produced when glucose attaches to hemoglobin in the RBC.
glycogen	The storage form of glucose in humans and animals.
glycogenolysis	Hydrolysis of glycogen to yield free glucose.
glycosuria	Presence of glucose in the urine.
GnRH	Gonadotropin releasing hormone (also called luteinizing releasing hormone); hormone released by the hypothalamus that stimulates the anterior pituitary to secrete LH and FSH.
goiter	Condition in which the thyroid is enlarged, but not as a result of a tumor.
gonads	Organs that produce male (testes) or female (ovaries) sex cells, sperm or ova.
gram negative	Bacteria that retain only the red stain in a gram stain.
gram positive	Bacteria that retain only the purple stain in a gram stain.
gram stain	Method of staining and identifying bacteria using crystal violet (purple) and safranin (red) stains.
grand mal	Older term for a generalized seizure characterized by full-body tonic and clonic motor convulsions.

H

half-life	Time required for the body to reduce the amount of drug in the plasma by one-half.
hallucinogenic drug	A drug or plant substance that produces psychotomimetic effects and sensory distortions.
halogenated hydrocarbon	Compound that contains halogen (chlorine, fluorine, bromine, iodine) combined with hydrogen and carbon.
hashish	Resin from the marijuana plant that contains higher levels of THC.
hCG	Human chorionic gonadotropin. A glycoprotein hormone produced in pregnancy to maintain progesterone production.
heart rate (HR)	Number of heartbeats per minute.
heartburn (acid indigestion)	A painful burning feeling behind the sternum that occurs when stomach acid backs up into the esophagus.
hematinic	Medications containing iron compounds, used to increase hemoglobin production.
hematuria	Appearance of blood or red blood cells in the urine.
hemoglobin	Protein in red blood cells that transports oxygen to all tissues of the body.
hemorrhage	Loss of blood from blood vessels.
hemozoin	Crystalline disposal product from the digestion of blood from blood-feeding parasites.
hepatic microsomal metabolism	Specific enzymes in the liver (P450 family) that metabolize some drugs and can be increased (stimulated) by some medications or decreased (inhibited) by other medications so that therapeutic drug blood levels are altered.
hernia	Protrusion of an organ through the tissue usually containing it; for example, intestinal tissue pushing outside the abdominal cavity, or stomach pushing into the diaphragm (hiatal hernia).
high-density lipoprotein (HDL)	One of the forms of cholesterol transported in the blood with lipoprotein; known as “good” cholesterol.
hirsutism	Condition usually in women in which body and facial hair is excessive.
histamine	Substance that interacts with tissues to produce most of the symptoms of allergy.
HIV	Human immunodeficiency virus, responsible for producing AIDS.
hives	A skin condition characterized by intensely itching wheals caused by an allergic reaction; also called urticaria.
homeostasis	Normal state of balance among the body’s internal organs.
H1N1	subtype of the influenza type A virus; also referred to as swine flu or pig flu
hormone	Substance produced within one organ and secreted directly into the circulation to exert its effects at a distant location.
hyperacidity	Abnormally high degree of acidity (for example, pH less than 1) in the stomach.
hyperalgesia	An abnormally painful response to a stimulus.
hypercalcemia	Unusually high concentration of calcium in the blood; high serum calcium; elevated concentration of calcium ions in the circulating blood.
hyperchloremia	Abnormally high level of chloride ions circulating in the blood.
hyperchlorhydria	Excess hydrochloric acid in the stomach.
hyperemia	Increased blood flow to a body part like the eye; engorgement.
hyperglycemia	Higher than normal level of glucose in the blood; fasting blood glucose higher than 126 mg/dl.
hyperinsulinemia	High levels of insulin in the blood often associated with type 2 diabetes mellitus and insulin resistance.
hyperkalemia	High serum potassium.
hyperlipidemia	Abnormally high fat (lipid) levels in the plasma.
hypermotility	Increase in muscle tone or contractions causing faster clearance of substances through the GI tract.
hyperpolarized	An increase in the amount of electrical charge on either side of a cell membrane so that there is an increase in the electric potential across the membrane usually due to an outflow of potassium ions or an inflow of chloride ions. A change in the cell membrane potential that makes the inside of the cell even more negative, so it can’t respond to stimulation.
hypersensitivity	Exaggerated response such as rash, edema, or anaphylaxis that develops following exposure to certain drugs or chemicals.
hypertension	Abnormally high blood pressure.
hyperthermia	Abnormally high body temperature.
hypertonic	A condition where the concentration of salt (sodium, electrolytes) is greater than that found inside the cells.
hypervitaminosis	The accumulation of vitamins (fat soluble) in storage tissues that creates a deleterious condition related to the excess substance.
hypnotic	Drug used to induce and maintain sleep.
hypochloremia	Abnormally low level of chloride ions circulating in the blood.
hypochromic	Condition in which the color of red blood cells is less than the normal index.
hypoglycemia	Lower than the normal range of plasma glucose concentration in the blood; fasting blood glucose below 40 mg/dl in women or 50 mg/dl in men accompanied by symptoms of diabetes.
hypokalemia	Abnormally low level of potassium ions circulating in the blood; low serum potassium; decrease in the normal concentration of potassium in the blood.
hypolipidemic drug	Drug used to lower plasma lipid levels, also referred to as an antilipemic drug.
hyponatremia	Abnormally low level of sodium ions circulating in the blood.
hypophosphatemia	Abnormally low concentrations of phosphate in the circulating blood.
hypothalamus	Part of the brainstem that regulates functions such as body temperature, water balance, appetite, and the pituitary gland; center of the brain that influences mood, motivation, and the perception of pain.
hypotonic	A condition where the concentration of salt (sodium, electrolytes) is less than that found inside the cells.
hypoxia	Reduction of oxygen supply to tissues below the amount required for normal physiological function.

 

I

IA (intra-articular)	Joint space into which drug is injected.
IBS (irritable bowel syndrome)	A functional disorder of the colon with abdominal pain, cramping, bloating, diarrhea. and/or constipation.
IGF (insulin-like growth factor)	A stimulator of cell growth and proliferation.
immunity	Condition that causes individuals to resist acquiring or developing a disease or infection.
immunomodulation	Ability to stimulate and increase immune function.
immunopharmacology	Study of drugs with immunosuppressive and immunomodulating actions.
immunosuppressed	Having inhibition of the body’s immune response (ability to fight infection), usually induced by drugs or viruses.
immunosuppression	Ability to reduce the activity of the immune system.
improper fraction	Fraction that has a value equal to or greater than 1.
incompatibility	Undesirable interaction of drugs not suitable for combination or administration together.
incretins	A group of gastrointestinal hormones that increase the amount of insulin released.
individual variation	Difference in the effects of drugs and drug dosages from one person to another.
induction of general anesthesia	Time required to take a patient from consciousness to Stage III of anesthesia.
infarction	Area of tissue that has died because of a sudden lack of blood supply.
infiltration anesthesia	Injection of a local anesthetic directly into the tissue.
inflammation	Condition in which tissues have been damaged, characterized by swelling, pain, heat, and sometimes redness.
insulin	Hormone secreted by the beta cells of the pancreas to facilitate glucose entry into the cell.
insulin-like growth factor (IGF)	A stimulator of cell growth and proliferation.
interferon	Chemical mediator produced by immune cells that increases immune function.
interleukin	Chemical mediator produced by immune cells that helps regulate and increase immune function.
intermittent claudication	Severe pain in the calf muscles that occurs while walking, but subsides with rest.
intolerant	Not able to continue drug therapy usually because of extreme sensitivity to the side effects.
intoxication	State in which a substance has accumulated to potentially harmful levels in the body.
intra-articular (IA)	Joint space into which drug is injected.
intradermal anesthesia	Injection of a local anesthetic into the part of the skin called the dermis.
intramuscular (IM) injection	Route of drug administration; drug is injected into gluteal or deltoid muscles.
intrathecal	Space around the brain and spinal cord that contains the cerebrospinal fluid.
intravenous (IV) injection	Route of drug administration; drug is injected directly into a vein.
intrinsic factor	Protein necessary for intestinal absorption of vitamin B12; lack of intrinsic factor leads to pernicious anemia.
iodophor	Compound containing iodine.
irrigation	Washing (lavage) of a wound or cavity with large volumes of fluid.
irritable bowel syndrome (IBS)	A functional disorder of the colon with abdominal pain, cramping, bloating, diarrhea, and/or constipation.
ischemia	Insufficient blood supply (and oxygen) to meet the needs of the tissue or organ; condition of insufficient tissue blood flow; reduction in blood supply and oxygen to localized area of the body or tissue insufficient blood flow to a tissue.
islets	Group or island of cells.
isotonic	Normal salt concentration of most body fluids; a salt concentration of 0.9 percent.
IV fluid therapy	The infusion of large amounts of fluid into a vein to increase blood volume or supply nourishment.

K

keratinized	Composed of a protein substance largely found in hair and nails.
kerion	An inflammation of the hair follicles of the beard or scalp caused by ringworm with swelling and pus.
ketosis	Condition associated with an increased production of ketone bodies as a result of fat metabolism.

L

lactation	Production of milk in female breasts.
lavage	Washing with fluids or flushing of a cavity such as the stomach.
laxative	A substance that promotes bowel movements.
LD50	Lethal dose 50, or dose that will kill 50 percent of the laboratory animals tested.
leucopenia (leukopenia)	An abnormal decrease (less than normal) in the number of circulating white blood cells; condition in which the total number of white blood cells circulating in the blood is less than normal.
leukotrienes	Chemical mediators involved in inflammation and asthma.
LH	Luteinizing hormone in the female stimulates ovulation, and in the male stimulates testosterone synthesis and release; in the male also called ISCH (interstitial cell stimulating hormone).
limbic system	Neural pathway connecting different brain areas involved in regulation of behavior and emotion.
lipodystrophy	Defective metabolism of fat.
lipoprotein	A molecule that contains a protein and a lipid (fat).
lithium	An element similar to sodium that is used in the treatment of mania and bipolar mood disorder.
loading dose	Initial drug dose administered to rapidly achieve therapeutic drug concentrations.
local anesthetic	Drug that reduces response to pain by affecting nerve conduction. The action can be limited to an area of the body according to the site of administration.
low-density lipoprotein (LDL)	One of the forms of cholesterol transported in the blood with lipoprotein; known as “bad” cholesterol.
lymphokine	A substance secreted by T cells that signals other immune cells like macrophages to aggregate.
lymphopenia	Decrease in the number of circulating lymphocytes.
lyse	To disintegrate or dissolve.
lysosome	Part of a cell that contains enzymes capable of digesting or destroying tissue/proteins.

M

maintenance dose	Dose administered to maintain drug blood levels in the therapeutic range; daily dosage of cardiac glycoside that maintains effective drug levels in the blood.
maintenance of general anesthesia	Ability to keep a patient safely in Stage III of anesthesia.
major depressive disorder (MDD)	Depression that arises from within an individual and requires psychotherapy and drug treatment.
malabsorption	Inadequate ability to take in nutrients through the intestine.
malaria	Protozoal infection characterized by attacks of chills, fever, and sweating.
malignant	Life-threatening; refers to growth of a cancerous tumor.
malignant hypertension	Condition of hypertensive crisis where the high BP is causing vascular inflammation and necrosis of the blood vessels; hypertensive crisis associated with inflammation and vascular damage.
malignant hyperthermia	Condition in susceptible individuals resulting in a life-threatening elevation in body temperature.
mania	Mental state of excitement, hyperactivity, and excessive elevation of mood.
mechanism of action	Explanation of how a drug produces its effects.
medulla oblongata	Lower part of the brainstem that controls cardiac, vasomotor, and respiratory functions.
medullary depression	Inhibition of automatic responses controlled by the medulla, such as breathing or cardiac function.
medullary paralysis	Condition in which overdose of anesthetic shuts down cardiovascular and respiratory centers in the medulla, causing death.
mega-	Prefix meaning large.
megaloblast	Large, immature cell that cannot yet function as a mature red blood cell (RBC).
megaloblastic anemia	Condition in which there is a large, immature form of the red blood cell, which does not function as efficiently as the mature form.
meiosis	Type of cell division where diploid parent cells (46 chromosomes) divide, producing haploid cells (23 chromosomes); occurs only during gamete production.
menarche	First menstruation (endometrial tissue sloughing) during puberty.
menopause	Condition in which menstruation no longer occurs, either because of the normal aging process in women (45 years of age and older) or because the ovaries have been surgically removed (any age); the clinical effects of menopause are a direct result of little or no estrogen secretion.
menstruation	shedding of endometrial tissue with accompanying bleeding; the first day of the menstrual cycle.
metabolic waste products	Substances formed through the chemical processes that enable cells to function; usually, these substances are excreted by the body.
metastasis	Spread of cancer cells throughout the body, from primary to secondary sites.
methemoglobin	An altered hemoglobin that can no longer carry oxygen due to a change (oxidation) in iron from ferrous (Fe2+) to ferric state (Fe3+).
micro-	Prefix meaning small.
microcilia	Tiny hairs that line the respiratory tract and continuously move, pushing secretions toward the mouth.
microfilaments	Minute fibers located throughout the cytoplasm of cells, composed of the protein actin, that maintain the structural integrity of a cell.
mineralocorticoid	Steroid produced within the adrenal cortex that directly influences sodium and potassium metabolism.
miotic	A substance that causes constriction of the pupil or miosis.
mitochondria	Normal structures responsible for energy production in cells.
mitosis	Cell division in which two daughter cells receive the same number of chromosomes (46) as the parent cell; the process in cell division by which the nucleus divides.
mixed-function oxidase system	Drug microsomal metabolizing enzymes (DMMS) that decrease with age and slow the rate of drug oxidation and metabolism.
mixed number	Number written with both a whole number and a fraction.
moniliasis	Fungal infection previously called monilia, now known to be Candida albicans.
monoamine oxidase (MAO)	Enzyme that inactivates norepinephrine and serotonin.
Monoamine Theory of Mental Depression	Theory that mental depression is caused by low brain levels of norepinephrine and serotonin (monoamines).
monophasic	A fixed amount (nonchanging) of estrogen is released during the cycle.
morphology	Shape or structure of a cell.
mucolytic	Drug that liquefies bronchial secretions.
mucopolysaccharide	Naturally occurring substance formed by the combination of protein with carbohydrates (saccharides).
mu-opioid receptor antagonist	Drugs that block the mu protein receptor for opioids.
muscarinic receptor	An older but more specific term for the cholinergic receptor on smooth and cardiac muscle.
mutagenic	Having the ability to cause mutations.
myalgia	Pain associated with muscle injury.
mycosis	Any disease caused by a fungus.
myelin	The fatty substance that covers and protects nerves and allows efficient conduction of action potentials down the axon.
myelosuppression	Suppression of bone marrow activity that interferes with the production of all blood cells; causes anemia, increased infections, and bleeding problems.
myocardial infarction (MI)	Sudden death of an area of heart muscle, commonly referred to as a heart attack.
myocardium	The muscular layer of the heart.
myoclonic	Generalized seizures that are usually brief and often confined to one part of the body.
myxedema	Condition associated with a decrease in thyroid function, caused by removal of thyroid tissue or loss of tissue function because of damage to cells; also associated with subcutaneous edema and slowed metabolism.

N

Na/K adenosine triphosphatase (Na/K ATPase)	Enzyme that energizes the sodium/potassium pump and isinhibited by cardiac glycosides.
native	Natural substance in the body.
nephritis	Inflammation of the glomeruli often following a streptococcus infection.
nephrosis	A degenerative disease of the kidneys, characterized by generalized edema, protein in the urine, and an increase in serum cholesterol.
nerve conduction	Transfer of impulses along a nerve by the movement of sodium and potassium ions.
neuroleptanalgesia	Condition in which a patient is quiet and calm and has no response to pain after the combined administration of an opioid analgesic (fentanyl) and a tranquilizer (droperidol).
neuroleptanesthesia	State of unconsciousness plus neuroleptanalgesia produced by the combined administration of nitrous oxide, fentanyl, and droperidol.
neuroleptic malignant syndrome (NMS)	Toxic syndrome associated with the use of antipsychotic drugs.
neuromuscular junction (NMJ)	Space (synapse) between a motor nerve ending and a skeletal muscle membrane that contains acetylcholine (ACH) receptors.
neuropathic pain	Pain resulting from a damaged nervous system or damaged nerve cells.
neurotransmitter	Substance that stimulates internal organs to produce characteristic changes associated with sympathetic and parasympathetic divisions.
neurotransmitter-gated ion channel	Ion channels that open or close when a neurotransmitter binds to a receptor.
neutropenia	An abnormally low number of neutrophils (white blood cells).
nicotine	Alkaloid drug in tobacco that stimulates ganglionic receptors.
nicotinic-muscle (Nm) receptor	Cholinergic receptor located at the neuromuscular junction of skeletal muscle.
nicotinic-neural (Nn) receptor	Cholinergic receptor at the autonomic ganglia; cholinergic receptor located on both sympathetic and parasympathetic ganglia.
NMJ (neuromuscular junction)	Space (synapse) between a motor nerve ending and a skeletal muscle membrane that contains acetylcholine (ACH) receptors.
nociceptor	Specialized peripheral nerve cells sensitive to tissue injury that transmit pain signals to the brain for interpretation of pain.
nonbarbiturate	Refers to sedative-hypnotic drugs that do not possess the barbituric acid structure, such as benzodiazepines and related drugs.
nondepolarizing blocker	Produces paralysis by inhibiting nerve transmission.
nonopioid analgesic	Formerly known as nonnarcotic analgesics, such as NSAIDs and COX-2 inhibitors.
nonprescription, over-the-counter (OTC) drug	Drug that can be purchased without the servicesof a physician.
nonselective	Interacts with any subtype receptor.
nonselective beta-adrenergic blocker	Drug that blocks both beta-1 and beta-2 adrenergic receptors.
nonselective beta-adrenergic drug	Drug that stimulates both beta-1 and beta-2 receptors.
norepinephrine (NE)	Neurotransmitter of sympathetic (adrenergic) nerves that stimulates the adrenergic receptors.
normocytic anemia	Anemia in which RBCs are normal size and usually contain normal hemoglobin but are insufficient to carry adequate oxygen to the tissues; low RBC count.
nosocomial	Infection acquired as a result of being in a hospital.
NREM sleep	Stages of sleep characterized by nonrapid eye movement (NREM).
nucleoside	Molecule that contains purine or pyrimidine bases in combination with sugar (ribose or deoxyribose linkage).
numerator	Top number of a fraction; shows the part.

O

oligospermia	Reduced sperm count.
oliguria	Condition in which very small amounts of urine are produced.
on-off phenomenon	Alternating periods of movement mobility and immobility.
onychomycosis	A fungus infection of the nail; onycho-: pertaining to a claw or nail.
oocyst	A thick-walled structure in which parasitic protozoal sex cells develop for transfer to new hosts.
oocyte	the immature female reproductive cell prior to fertilization.
oogenesis	Formation of ova.
opiate	Drug derived from opium and producing the same pharmacological effects as opium.
opioid	Drug that produces the same pharmacological effects as opium and its family of drugs or the neuropeptides (enkephalin, endorphin) produced by the body.
opioid analgesics	Chemically related to morphine or opium and used to relieve pain.
opioid antagonist	A drug that attaches to opioid receptors and displaces the opioid analgesic or opioid neuropeptide.
opportunistic organism	Microorganism capable of causing disease only when the resistance (immunocompetence) of the host is impaired.
oral administration	Route of drug administration by way of the mouth through swallowing.
osmolality	The concentration of particles dissolved in a fluid.
osmolarity	A measure of hydration status; the amount of solute (ions, salts) per liter of solution (blood, plasma).
osmoreceptors	Specialized cells in the hypothalamus that respond to changes in sodium concentration (osmolarity) in the blood.
osmosis	Process in which water moves across membranes following the movement of sodium ions.
osteoblasts	Synthesize bone matrix proteins and promote crystal nucleation; contain receptors for PTH, vitamin D3, and estrogen.
osteoclasts	Responsible for bone resorption by binding to bone matrix proteins and releasing enzymes to break down bone.
osteoporosis	Condition associated with a decrease in bone density so that the bones are thin and fracture easily; decrease in the bone mineral density, usually in the elderly, that results in areas predisposed to fracture.
ova	Mature eggs, also termed oogonia. Ovum is singular; ova is plural.
ovulation	Release of an egg from the ovary.
oxyntic (parietal) cell	Cell that synthesizes and releases hydrochloric acid (HCl) into the stomach lumen.
oxytocin	Polypeptide substance released within the brain that has specific functions during and after pregnancy, specifically relating to the uterus and the mammary glands.

P

Paget’s disease	Condition in older adults in which the bone density is altered so that softening and bending of the weight-bearing bones occurs.
parasympathetic	Refers to nerves of the ANS that originate in the brain and sacral portion of the spinal cord; they are active when the body is at rest or trying to restore body energy and function.
parasympatholytic	Refers to drugs (anticholinergic) that decrease activity of the parasympathetic nervous system.
parasympathomimetic	Refers to drugs (cholinergic) that mimic stimulation of the parasympathetic nervous system.
parenteral administration	Route of drug administration that does not involve the gastrointestinal (GI) tract.
parietal (oxyntic) cell	Cell that synthesizes and releases hydrochloric acid (HCl) into the stomach lumen.
parkinsonism	Symptoms of Parkinson’s disease, which include resting tremor, muscle rigidity, and disturbances of movement and postural balance; disease or druginduced condition characterized by muscular rigidity, tremors, and disturbances of movement.
Parkinson’s disease	Movement disorder of the basal ganglia caused by a deficiency of dopamine.
partial seizure	Seizure originating in one area of the brain that may spread to other areas.
pathogen(ic)	Type of bacteria that cause disease; a microorganism that causes disease.
PCT (proximal convoluted tubule)	Part of the nephron that is closest to the glomerulus.
penicillinase	Bacterial enzymes that inactivate penicillin antibiotics.
pepsin	Enzyme that digests protein in the stomach.
percent	Decimal fraction with a denominator of 100.
percent composition	Common measure of solution concentration; refers to grams of solute per 100 ml of solution.
perforation	Opening in a hollow organ, such as a break in the intestinal wall.
perimenopause	Two to ten years before complete cessation of a menstrual period.
peripheral artery disease (PAD)	Any disease caused by the obstruction of blood flow in the large arteries of the arms and legs; usually a narrowing and hardening of these arteries that supply the legs and feet.
peripheral nerve	Part of the nervous system that is outside the central nervous system (the brain or spinal cord), usually near the surface of the tissue fibers or skin.
peripheral resistance (PR)	Resistance generated by the flow of blood through the arteries.
peripheral skeletal muscle relaxant	Drug that inhibits muscle contraction at the neuromuscular junction or within the contractile process.
peristalsis	Movement characteristic of the intestines, in which circular contraction and relaxation propel the contents toward the rectum.
permissive	Enables another hormone to fully function.
pernicious	Disease of severe symptoms, which could be fatal if left untreated.
petechia	Small area of the skin or mucous membranes that is discolored because of localized hemorrhages.
phagocyte	Circulating cell (such as a leukocyte) that ingests waste products or bacteria in order to remove them from the body.
pharmacokinetics	Describes the processes of drug absorption, drug distribution, drug metabolism, and drug excretion.
pharmacology	Study of drugs.
phlebitis	Inflammation of a vein.
phlegm	Secretion from the respiratory tract; usually called mucus.
physical dependence	Condition in which the body requires a substance (drug) not normally found in the body in order to avoid symptoms associated with withdrawal, or the abstinence syndrome.
plaque	Substance containing cholesterol, dead cell products, and calcium that accumulates in the innermost layer of the arteries.
pluripotent	Ability of a substance to produce many different biological responses.
polydipsia	Excessive thirst; increased thirst.
polypeptide	Substance, usually large, composed of an indefinite number of amino acids.
polyphagia	Excessive hunger.
polypharmacy	The situation in patients whose treatment involves multiple drug prescriptions.
polyuria	Excessive urine production; increased urination.
pons	Part of the brainstem that serves as a relay station for nerve fibers traveling to other brain areas; also involved in sensory and motor functions.
porphyria (acute)	A genetic disease associated with excessive liver production of delta-aminolevulonic acid and characterized by intermittent hypertension, abdominal cramps, and psychosis.
postpartum	After childbirth.
postprandial	After a meal.
potency	Measure of the strength, or concentration, of a drug required to produce a specific effect.
potentiates	Produces an action that is greater than either of the components can produce alone; synergy.
preferred anesthetic	Produces adequate anesthesia with minimal side effects.
preload	Refers to venous return, the amount of blood returning to the heart that must be pumped.
premature atrial contraction (PAC)	Premature contraction of the atria, usually caused by an ectopic focus.
premature ventricular contraction (PVC)	Premature contraction of the ventricles, usually caused by an ectopic focus.
prescription drug	Drug for which dispensing requires a written or phone order that can only be issued by or under the direction of a licensed physician.
pressor	Tending to increase blood pressure.
proarrhythmia	An arrhythmia caused by administration of an antiarrhythmic drug.
prodrug	An inactive precursor of a drug, converted into its active form in the body by normal metabolic processes.
prohormone (anabolic androgen)	After ingestion is converted to the hormone testosterone.
proinflammatory	Tending to cause inflammation.
proper fraction	Fraction that has a value less than 1.
prophylactic	Process or drug that prevents the onset of symptoms (or disease) as a result of exposure before the reactive process can take place.
prophylaxis	Treatment or drug given to prevent a condition or disease; procedure or medication to prevent a disease, rather than to treat an existing disease.
proportion	A mathematical equation that expresses the equality between two ratios.
prostaglandin	Substance naturally found in certain tissues of the body; can stimulate uterine and intestinal muscle contractions and may cause pain by stimulating nerve endings; chemical mediators released from mast and other cells involved in inflammatory and allergic conditions.
proteolytic	Action that causes the decomposition or destruction of proteins.
protozoacidal	A substance, chemical solution, or drug that kills protozoa.
protozoan	Single-celled organism belonging to the genus Protozoa.
proximal convoluted tubule (PCT)	Part of the nephron that is closest to the glomerulus.
psychomotor stimulant	Amphetamine or related drug that increases mental and physical activity.
psychosis	Form of mental illness that produces bizarre behavior and deterioration of the personality.
psychotomimetic drug	Drug or substance that can induce psychic and behavioral patterns characteristic of a psychosis.
puberty	Sequence of physiological changes associated with the expression of sexual characteristics and reproductive function that occur when a child progresses into young adulthood, usually at 12 to 14 years of age.

R

radical cure	Arresting of malaria, in which protozoal parasites are eliminated from all tissues.
ratio	The relationship of one number to another expressed by whole numbers (1:5) or as a fraction (1/5).
RBC	Red blood cell.
receptor	Specific cellular structure that a drug binds to and that produces a physiologic effect.
recombinant	Genetically engineered DNA.
referred pain	Origin of the pain is in a different location than where the individual feels the pain.
refractory	Unable to produce an increased response even though the stimulation or amount of drug has been increased.
regional nerve block	Also called nerve block; the injection of a local anesthetic near the nerve root.
REM sleep	Stage of sleep characterized by rapid eye movement (REM) and dreaming.
remission	Period when cancer cells are not increasing in number.
renin	Enzyme released by the kidneys that converts angiotensinogen into angiotensin I.
replacement therapy	Administration of a naturally occurring substance that the body is not able to produce in adequate amounts to maintain normal function.
repolarization	Return of the electric potential across a cell membrane to its resting state following depolarization.
repository preparation	Preparation of a drug, usually for intramuscular or subcutaneous injection, that is intended to leach out from the site of injection slowly so that the duration of drug action is prolonged.
reticular formation	Network of nerve fibers that travel throughout the central nervous system that regulates the level of wakefulness.
Reye’s syndrome	A potentially fatal illness characterized by vomiting, an enlarged liver, convulsions, and coma, in children and adolescents; linked to the use of salicylates in the management of influenza, usually type B, or chickenpox.
rhabdomyolysis	The rapid breakdown of skeletal muscle (rhabdomyon) due to muscle injury.
rheumatic fever	Condition in which pain and inflammation of the joints or muscles are accompanied by elevated body temperature usually a complication of untreated Strep throat.
rigidity	A stiffness and inflexibility of movement.

S

SA	Sinoatrial, as in the SA node.
salicylism	Condition in which toxic doses of salicylates are ingested, resulting in nausea, tinnitus, and delirium.
sarcolemma	A thin membrane enclosing a striated (skeletal) muscle fiber.
sarcoplasm	The cytoplasm of a striated (skeletal) muscle fiber.
sarcoplasmic reticulum	Specialized organelle in the muscle cell that releases calcium ions during muscle contraction and absorbs calcium ions during relaxation.
schizophrenia	Major form of psychosis; behavior is inappropriate.
Schwann cell	Any cell that covers the axons in the peripheral nervous system and forms the myelin sheath.
sebum	A lipid substance secreted by glands in the skin to lubricate the skin everywhere but the palms and soles.
secondary hypertension	Form of hypertension in which the cause is known.
sedative	Drug used to produce mental relaxation and to reduce the desire for physical activity.
seizure	Abnormal discharge of brain neurons that causes alteration of behavior and/or motor activity.
selective	Interacts with one subtype of receptor over others.
selective beta-1 adrenergic blocker	Drug that blocks only beta-1 receptors.
selective beta-2 adrenergic drug	Drug that stimulates only beta-2 receptors at therapeutic doses.
selective COX-2 inhibitors	Drugs that only interact with one of the enzymes in the cyclooxygenase family.
sensitize	To induce or develop a reaction to naturally occurring substances (allergens) as a result of repeated exposure.
side effect	Drug effect other than the therapeutic effect that is usually undesirable but not harmful.
site of action	Location within the body where a drug exerts its therapeutic effect, often a specific drug receptor.
solute	Substance dissolved in a solvent; usually present in a lesser amount.
solution	Homogeneous mixture of two or more substances.
solvent	Liquid portion of a solution that is capable of dissolving another substance.
somatomedins	Peptides in the plasma that stimulate cellular growth and have insulin-like activity.
somatostatin	An inhibitory hormone that blocks the release of somatotropin (GH) and thyroid-stimulating hormone (TSH).
somatotropin	Another term for growth hormone (GH).
spasmogenic	Causing a muscle to contract intermittently, resulting in a state of spasms.
spasmolytics	Drugs that relieve, interrupt, or prevent muscle spasms (intermittent muscle contractions often associated with pain).
spermatogenesis	Formation of spermatozoa.
spermatogonia	Intermediary kind of male germ cell in the production of spermatozoa.
spermatozoa	Mature sperm cells (singular spermatozoon).
spinal anesthesia	Injection of a local anesthetic into the subarachnoid space.
SSRIs	Selective serotonin reuptake inhibitors, a class of antidepressant drugs.
stable plaque	Plaque formed in the artery wall that remains in the wall.
-static	Suffix denoting the inhibition of, as of microorganisms.
status epilepticus	Continuous series of generalized tonic and clonic seizures, a medical emergency requiring immediate treatment.
sterilization	Process that results in destruction of all microorganisms.
steroid	Member of a large family of chemical substances (hormones, drugs) containing a structure similar to cortisone (tetracyclic cyclopenta-a-phenanthrene).
stroke	Loss of brain function due to a loss of blood supply.
stroke volume (SV)	Amount of blood pumped per heartbeat.
suppression therapy	Taking the drug daily even when there are no observable acute symptoms.
supraventricular arrhythmia	Arrhythmia that originates above the AV node in the atria.
suspension	Preparation in which undissolved solids are dispersed within a liquid.
sympathetic	Refers to nerves of the ANS that originate from the thoracolumbar portion of the spinal cord; they are active when the body is under stress or when it is exerting energy.
sympatholytic	Refers to the action of an adrenergic blocking drug or an action that decreases sympathetic activity.
sympathomimetic	Refers to the action of an adrenergic drug or an action that increases sympathetic activity.
synaptic knob	Contains vesicles that store and release neurotransmitters.
synaptic vesicles	A small membrane-bound structure in the axon terminals of nerve cells that contains neurotransmitters and releases them when an action potential reaches the terminal.
synergistic	Complementary or additive.
synergism	When the action resulting from a combination of drugs is greater than the sum of their individual drug effects.
synesthesia	Distortion of sensory perception; usually associated with the use of LSD.
synthetic drug	Drug produced by a chemical process outside the body.
systemic	Occurring in the general circulation, resulting in distribution to most organs.

T

T3 and T4	Hormones (triiodothyronine and thyroxine, respectively) synthesized and released by the thyroid gland. Synthesized T4 must be converted to T3 to be utilized by the cell.
tardive dyskinesia	Drug-induced involuntary movements of the lips, jaw, tongue, and extremities.
target organ	Specific tissue where a hormone exerts its action.
TCAs	Tricyclic antidepressants, a class of antidepressant drugs.
tenesmus	A painful spasm of the anal sphincter, causing an urgent desire to defecate although little or no material is passed.
teratogenic	Capable of causing birth defects or fetal abnormalities or development; capable of causing abnormal development.
tetany	A strong sustained muscle contraction.
tetrahydrocannabinol (THC)	Active ingredient of the marijuana plant.
thalamus	Uppermost part of the brainstem that regulates sensory and motor impulses traveling to and from the cerebral cortex.
therapeutic dose	The amount (dose) of drug required to produce the desired change in the disease or condition.
therapeutic effect	Desired drug effect to alleviate some condition or symptom of disease.
therapeutic index (TI)	Ratio of the LD50 to the ED50 in animal studies.
thrombocyte	Cell in the blood, commonly called a platelet, that is necessary for coagulation.
thrombocytopenia	An abnormal decrease in the number of circulating platelets.
thromboembolism	Clots that jam a blood vessel; formed by the action of platelets and other coagulation factors in the blood.
thrombophlebitis	Inflammation of the walls of the veins, associated with clot formation.
thrombus	Clot formed by the action of coagulation factors and circulating blood cells.
thrush	Term used for Candida infection in the mucous membranes of the mouth and pharynx.
thyrotoxic crisis	Condition caused by excessive quantities of thyroid hormone, from either a natural source of hypersecretion or exogenous administration of a drug.
thyroxine (T4)	Hormone synthesized and released by the thyroid gland.
TIA (transient ischemic attack)	An interruption of blood flow to the brain for a short period of time; a ministroke that produces stroke-like symptoms but no lasting damage.
tolerance	Ability of the body to alter its response (to adapt) to drug effects so that the effects are minimized over time.
tonic	Convulsive muscle contraction characterized by sustained muscular contractions.
tonic-clonic	Generalized seizure characterized by fullbody tonic and clonic motor convulsions and loss of consciousness.
topical application	Placing a drug on the surface of the skin or a mucous membrane (for example, mouth, rectum).
torsade de pointes	A type of proarrhythmia that causes ventricular tachycardia and fainting.
toxic effect	Undesirable drug effect that implies drug poisoning; can be very harmful or life-threatening.
TPN	Total parenteral nutrition; a combination of nutrients that may include amino acids, carbohydrates, vitamins, and minerals (electrolytes) that is infused into patients who cannot absorb these substances from the gastrointestinal tract because of condition or disease; the combination and concentration of nutrients vary according to patient need.
trade name	Patented proprietary name of drug sold by a specific drug manufacturer; also referred to as the brand name.
transdermal absorption	Absorption of drug (substance) through the skin, usually associated with the application of drug-loaded patches.
transient ischemic attack (TIA)	An interruption of blood flow to the brain for a short period of time; a ministroke that produces stroke-like symptoms but no lasting damage.
transit time	Amount of time it takes for food to travel from the mouth to the anus.
tremor	A trembling and involuntary rhythmic movement.
TRH	Thyroid-releasing hormone, secreted by the hypothalamus.
trichomoniasis	Infection caused by the Trichomonas organism; a sexually transmitted disease.
triglyceride	A fat formed by three fatty acids into one molecule that supplies energy to muscle cells.
triiodothyronine (T3)	Hormone synthesized and released by the thyroid gland.
triphasic	The estrogen and progestin amounts released may vary during the cycle.
tropic	Having an affinity for the designated organ; for example, adrenotropic.
tropic hormone	Hormone secreted by the anterior pituitary that binds to a receptor on another endocrine gland.
TSH	Thyroid-stimulating hormone, secreted by the anterior pituitary.
tubular reabsorption	Process in which the nephrons return to the blood substances (ions, nutrients) that were filtered out of the blood at the glomerulus.
tubular secretion	Process in which the nephrons produce and release substances (ions, acids, and bases) that facilitate sodium ion reabsorption and maintain acid-base balance.
tumor	Uncontrolled growth of abnormal cells that form a solid mass; also called a neoplasm.
type 1 diabetes	Insulin-dependent diabetes mellitus.
type 2 diabetes	Non-insulin-dependent diabetes mellitus.

U

ulcer	Open sore in the mucous membranes or mucosal linings of the body.
ulcerogenic	Capable of producing minor irritation or lesions to an integral break in the mucosal lining (ulcer).
unstable plaque	Plaque formed in the artery wall that can break away and obstruct blood flow or form a clot.
uremia	Accumulation of nitrogen waste materials (for example, urea) in the blood.
urticaria	Intensely itching raised areas of skin caused by an allergic reaction; hives.

V

vagolytic action	Inhibition of the vagus nerve to the heart, causing the heart rate to increase (counteraction to vagal tone that causes bradycardia).
variant or Prinzmetal angina	Angina pectoris caused by vasospasm of the coronary arteries.
vasoconstriction	Tightening or contraction of muscles (sphincters) in the blood vessels, which decreases blood flow through the vessels.
vasodilation	Relaxation of the muscles (sphincters) controlling blood vessel tone, which increases blood flow through the vessels.
vasodilator	Substance that relaxes the muscles (sphincters) controlling blood vessels, leading to increased blood flow.
vasopressin	Man-made form of ADH. Because of ADH’s fluid reabsorption and vasoconstrictive properties, can elevate blood pressure at higher doses.
ventricular fibrillation	The most serious arrhythmia; usually a terminal event where ventricular contractions are no longer able to effectively pump blood.
very-low-density lipoprotein (VLDL)	Molecules made of cholesterol, triglycerides, and protein that carry cholesterol from the liver to organs and tissues; also serves as a precursor to low density lipoproteins (LDL).
virilization	Development of masculine body (hair, muscle) characteristics in females.
virucidal	Substance, chemical solution, or drug that kills viruses; chemical that kills or destroys viruses.

W

wheal

A firm, elevated swelling of the skin often pale red in color and itchy; a sign of allergy.

X

xerostomia

Dryness of the oral cavity resulting from inhibition of the natural moistening action of salivary gland secretions or increased secretion of salivary mucus, rather than serous material.