A-H (copy)

2,3-Diphosphoglycerate

A compound in red blood cells that affects oxygen binding to and release from hemoglobin.

Ablation

Destruction of part or all of an organ or structure.

Abscess

Purulent collection of fluid separated from surrounding tissue by a wall consisting of inflammatory cells and adjacent organs.

Acanthosis nigricans

Increased thickness and hyperpigmentation of the outer cell layers of the skin; typically observed at areas of flexure.

Acaricide

A chemical that kills mites and ticks.

Acetylcholine

Neurotransmitter at synapses in the ganglia of the visceral motor system and a variety of sites within the central nervous system.

Achalasia

Disorder in which the esophageal sphincter is impaired, preventing normal swallowing and often causing reflux of contents and a feeling that something is caught in the throat.

Achlorhydria

Absence of free hydrochloric acid in the stomach.

Acinar cells

Cells in the pancreas responsible for the synthesis, secretion, and storage of certain digestive enzymes.

Action potential

A rapid change in the polarity of the voltage of a cell membrane from negative to positive and back to negative; a wave of electrical discharge that travels across a cell membrane.

Acute coronary syndromes

Ischemic chest discomfort at rest often accompanied by ST-segment elevation, ST-segment depression, or T-wave inversion on the 12-lead electrocardiogram; caused by plaque rupture and partial or complete occlusion of the coronary artery by thrombus.

Acute respiratory distress syndrome

Diffuse inflammatory condition of the lung resulting in damage of alveoli, surfactant production, innate immune system response, and dysregulation of hemostasis in the pulmonary tract.

Addiction

A primary, chronic, neurobiologic disease characterized by behaviors such as impaired control over substance use, compulsive use, continued use despite harm, and craving.

Adenoma

A non-malignant tumor of the epithelial tissue characterized by glandular structures.

Adenomatous polyposis coli

A gene associated with familial adenomatous polyposis, an inherited disorder characterized by the development of myriad polyps in the colon.

Adjuvant chemotherapy

Treatment given after primary surgical treatment designed to eliminate any remaining undetectable cancer cells.

Adrenalectomy

Surgical removal of an adrenal gland.

Adverse drug reaction

Any unexpected response to a medication that requires modification or discontinuation.

Aeroallergen

Airborne substance that causes an allergic response.

Afterload

The force against which a ventricle contracts, contributed to by the vascular resistance.

Ageism

Discrimination against aged persons.

Air embolus

An obstruction in a small blood vessel caused by air that is introduced into the blood vessel.

Akathisia

Motor or subjective feelings of restlessness, often characterized by the urge to move limbs.

Akinesia

Lack of movement.

Allodynia

Pain that results from a stimulus that does not normally cause pain.

Allogeneic

A transplant taking cells from one person and donating them to another.

Allogeneic hematopoietic stem cell transplant (HSCT)

Procedure in which a patient receives hematopoietic stem cells from a genetically similar donor.

Allograft

Tissue or organ transplanted from a donor of the same species but different genetic makeup.

Allograft survival

The continued function of a transplanted organ.

Allorecognition

Recognition of the foreign antigens present on the transplanted organ.

Alopecia

Hair loss.

Ambulatory esophageal reflux monitoring

Monitoring method to determine reflux occurrence using a telemetry capsule.

Amenorrhea

The absence or discontinuation of regular menstrual periods.

Ampulla of Vater

Dilation of the duodenal wall at the opening of the pancreatic and common bile ducts.

Amylin

A polypeptide hormone secreted from the pancreas in response to nutrients.

Amyloid

Chemically diverse proteins accumulated as aggregated fibrils.

Anaerobic

Living in the absence of oxygen.

Anaphylactic/anaphylaxis

Immediate, severe hypersensitivity reaction induced by an antigen.

Anaphylactoid

An anaphylactic-like reaction not mediated by IgE.

Anastomosis

Connection of two hollow organs to restore continuity after resection.

Androgen deprivation therapy

Agents used to suppress testosterone levels consistent with medical castration.

Anergy

A reduction or lack of an immune response to a specific antigen.

Aneurysm

A blood-filled bulge in a weakened blood vessel wall.

Angioedema

Swelling beneath the skin, often leading to airway obstruction.

Angiogenesis

The formation of new blood vessels.

Angiography

Examination of blood vessels using x-rays after injection of a radiopaque substance.

Anosmia

Loss of smell.

Anovulatory cycle

Menstrual cycle where ovaries fail to produce or release egg.

Anterior circulation

Blood supply to the anterior section of the brain.

Anterograde amnesia

Inability to create new memories.

Anticitrullinated protein antibodies

Autoantibodies directed against cyclic citrullinated peptide.

Anticoagulant

Any substance that inhibits the formation of blood clots.

Antiprotease

A substance that inhibits the activity of a protease.

Aortic dissection

A serious condition involving a tear in the aorta.

Aortic stenosis

Narrowing of the aortic valve opening.

Aphakic

Absence of a lens in the eye.

Aphasia

Impairment of language affecting ability to speak and understand speech.

Aphthous ulcer

A superficial area of ulceration in the gastrointestinal mucosa.

Aplasia cutis

Congenital absence of skin.

Apoptosis

Programmed cell death as signaled by the cells.

Arcuate scotoma

An arc-shaped area of blindness.

Arteriovenous malformation

A tangle of blood vessels that results in abnormal connections.

Arthrocentesis

Puncture and aspiration of a joint.

Articular

Related to the joints of the body.

Ascites

Accumulation of fluid within the peritoneal cavity.

Asterixis

Involuntary jerking movements primarily seen in metabolic conditions.

Astringent

A substance causing tissues to constrict and dry the skin.

Atelectasis

Decreased or absent air in a lung.

Atherosclerosis

Accumulation of lipids and inflammatory cells in arterial walls.

Atherosclerotic cardiovascular disease

Disease where plaque builds up in vessels.

Atresia

Congenital absence of a normal opening.

Atrophic urethritis

Thinning and inflammation of the vaginal walls due to decreased estrogen.

Attenuated

Loss of intensity or virulence.

Aura

Visual or sensory disturbance occurring before a migraine or seizure.

Auspitz sign

Pinpoint bleeding when a psoriasis scale is peeled from the skin.

Autologous

A transplant using one’s own stem cells.

Autologous hematopoietic stem cell transplant (HSCT)

Procedure where stem cells are removed, stored, and infused back into the same patient.

Autoreceptor

Transmitter receptors sensitive to release from the terminal itself.

Avolition

Inability to initiate and persist in goal-directed activities.

Azoospermic

Having no living spermatozoa or failure of spermatogenesis.

Bacteremia

Presence of bacteria in the blood.

Barium enema

Diagnostic test using x-ray to view the lower gastrointestinal tract.

Barrett esophagus

Change of normal esophagus lining to metaplastic columnar epithelium.

Basal ganglia

Cluster of nerve cells that coordinate normal movement.

Bence–Jones proteins

Light chained immunoglobulins found in urine.

β-Hydroxybutyric acid

A ketone body elevated in ketosis, synthesized in the liver.

β-Lactam allergy

Allergy to the β-lactam antibiotic family.

β2 microglobulin

A low molecular weight protein that may be elevated in multiple myeloma.

Bilateral salpingo-oophorectomy

Surgical removal of both ovaries and fallopian tubes.

Bile acids

Organic acids in bile involved in fat emulsification.

Biliary sludge

Deposits of tiny stones or crystals in bile leading to gallstones.

Biopsy

Removal of cells or tissue for examination.

Bladder hypotonicity

Low elastic tension of the bladder.

Blast

An immature cell.

Blastospores

Asexual reproductive spores formed by budding.

Blood urea nitrogen (BUN)

Waste product from the breakdown of dietary proteins.

Body mass index

Calculation of weight in relation to height.

Bouchard nodes

Hard, bony enlargement of finger joints.

Boutonniere deformity

Joint deformity associated with rheumatoid arthritis.

Brachial plexus

Collection of nerves supplying parts of the shoulder and arm.