A-H 4

Extraction ratio: Fraction of the drug entering the liver in the blood which is irreversibly removed. Extrapyramidal symptoms (EPS): Adverse drug effects of medications such as phenothiazines. EPS include dystonia (involuntary muscle contractions), tardive dyskinesia (repetitive, involuntary movements), and akathisia (motor restlessness or anxiety). Extravasation: Movement of fluid from inside a blood vessel into the surrounding tissues. Facultative: An optional biological condition, not required for growth or survival. Felty syndrome: An extra-articular manifestation of rheumatoid arthritis associated with splenomegaly and neutropenia. Ferritin: A protein in the body that binds to iron; most of the iron stored in the body is bound to ferritin. Festination: Walking with short, rapid, shuffling steps. Fibrin: An insoluble protein that is one of the principal ingredients of a blood clot. Fibrin strands bind to one another to form a fibrin mesh. The fibrin mesh often traps platelets and other blood cells. Fibrinolysis: A normal ongoing process that dissolves fibrin and results in the removal of small blood clots; hydrolysis of fibrin. Fibroadenoma: A benign neoplasm which commonly occurs in breast tissue and is derived from glandular epithelium. Fibrosis: Development of fibrous connective tissue in response to injury or damage. Fluorescence in situ hybridization (FISH): A laboratory technique used to look at genes or chromosomes in cells and tissues. Pieces of DNA that contain a fluorescent dye are made in the laboratory and added to cells or tissues on a glass slide. When these pieces of DNA bind to specific genes or areas of chromosomes on the slide, they light up when viewed under a microscope with a special light. Fistula: Abnormal connection between two internal organs (eg, arteriovenous fistula is a connection between an artery and a vein), or between an internal organ and the exterior or skin (eg, enterocutaneous fistula is a connection between the intestine and the skin). Fistulogram: X-ray photograph (or radiograph) taken after injection of a contrast material or radiopaque material (material that will not allow passage of x-rays and will be visible in an x-ray photograph [or radiograph]). Flexural psoriasis: Flexural psoriasis is characterized by lesions found in skin folds. These lesions tend to be erythematous plaques and are often found in the axillary, genital, perineal, intergluteal, and inframammary regions. While shiny, smooth, and deep red in color there may be skin fissures and the absence of the silvery scales. Flight of ideas: A nearly continuous flow of rapid speech and thought that jumps from topic to topic, usually loosely connected. Floppy iris syndrome: A syndrome of pupillary constriction, flaccid iris, and iris prolapse which can result in intraoperative complications during cataract surgery; associated with use of an α1 adrenergic antagonist (eg, tamsulosin). Flow cytometry: A method of measuring the number of cells in a sample, the percentage of live cells in a sample, and certain characteristics of cells, such as size, shape, and the presence of tumor markers on the cell surface. The cells are stained with a light-sensitive dye, placed in a fluid, and passed in a stream before a laser or other type of light. The measurements are based on how the light-sensitive dye reacts to the light. Foam cell: Lipid-laden white blood cell. Focal seizures: Seizures that start in a small area of the brain. They may stay localized or spread to involve larger areas or the entire brain. Forced expiratory volume in the first second (FEV1 ): The volume of air that a patient can forcibly exhale in the first second of forced exhalation after taking a maximal breath. Forced vital capacity: The maximum volume of air that can be forcibly exhaled after taking a maximal breath. Fraction of exhaled nitric oxide (FeNO): A noninvasive test that, when elevated, is an indicator of inflammation in the airways and likely responsiveness to inhaled corticosteroids. Fragility fracture: A fracture resulting from a fall from standing height or less amount of trauma. Frailty: Excess demand imposed upon reduced capacity; a common biological syndrome in the elderly. Frank-Starling mechanism: Increase in stroke volume in response to an increase in volume of blood filling the heart (ie, end diastolic volume) when all other factors remain constant. Freezing: A sudden but temporary inability to move. Fremitus: Vibrations through the chest wall that may be detected through touch (tactile) or heard (vocal) through a stethoscope with certain spoken words (eg, “ninety-nine”). French scale: Scale used to measure external diameter of a feeding tube. Fructooligosaccharide: Soluble fiber that is fermented by colonic bacteria to short-chain fatty acids (SCFAs). Gadolinium: An intravenous contrast agent used with magnetic resonance imaging. Gallstone (cholelithiasis): A solid formation in the gallbladder or bile duct composed of cholesterol and bile salts. γ-Aminobutyric acid (GABA): An inhibitory neurotransmitter. Gamma knife: A type of radiosurgery (radiation therapy) machine that acts by focusing low-dosage gamma radiation from many sources on a precise target. Gastric bypass: A surgical procedure for weight loss that elicits its effectiveness through malabsorption and gastric volume limitation. The procedure involves full partitioning of the proximal gastric segment into a jejunal loop. Gastritis: Inflammation of stomach lining. Gastroparesis: A form of autonomic neuropathy involving nerves of the stomach. It may include nausea, vomiting, feeling full, bloating and lack of appetite. It may cause wide fluctuations in blood sugars due to insulin action and nutrient delivery not occurring at the same time. Gastrostomy: Operative placement of a new opening into the stomach usually associated with feeding tube placement. Generalized seizures: A seizure where the entire cerebral cortex is involved from the onset of the seizure. Geniculate nucleus: The portion of the brain that processes visual information from the optic nerve and relays it to the cerebral cortex. Genotype: The genetic constitution of an individual. Geriatric syndrome: Age-specific presentations or differential diagnoses, including visual and hearing impairment, malnutrition and weight loss, urinary incontinence, gait impairment and falls, osteoporosis, dementia, delirium, sleep problems, and pressure ulcers; commonly seen conditions in older patients. Gleason score: System of histological grading used in prostate cancer. Individual scores range from 2 to 5. The two highest scores from each sample are combined for a total score (up to 10). Higher scores indicate higher grade and more aggressive tumor.

Glomerular filtration rate (GFR): The volume of plasma that is filtered by the glomeruli per unit time, usually expressed as mL/min or mL/min/1.73 m2 (and in some areas in SI units of mL/s or mL/s/m2), which adjusts the value for body surface area. This is the primary index used to describe overall renal function. Glomerulonephritis: Glomerular lesions that are characterized by inflammation of the capillary loops of the glomerulus. These lesions are generally caused by immunologic, vascular, or idiopathic diseases and lead to high blood pressure and possible loss of kidney function. Glucagon: Hormone involved in carbohydrate metabolism that is produced by the pancreas and released when glucose levels in the blood are low. When blood glucose levels decrease, the liver converts stored glycogen into glucose, which is released into the bloodstream. The action of glucagon is opposite of insulin. Gluconeogenesis: Formation of glucose from precursors other than carbohydrates especially by the liver and kidney using amino acids from proteins, glycerol from fats, or lactate produced by muscle during anaerobic glycolysis. Glucosuria: Presence of glucose in the urine. Glutamate: An excitatory amino acid found in the central nervous system. Glycogenolysis: The process by which glycogen is broken down to glucose in body tissues. Goiter: An enlargement of the thyroid gland, causing a swelling in the front part of the neck. Gonioscopy: Examination of the anterior chamber angle. A gonioprism or Goldman lens is used to perform gonioscopic evaluation. Graft-versus-host disease: A condition that results from donor immune cells attacking the normal tissue of a hematopoietic stem cell transplant recipient. Graft-versus-tumor effect: An immune response directed at a patient’s malignant cells that is the result of donor immune cell activation. Grandiosity: Exaggerated sense of self-importance, ideas, plans, or abilities. Granuloma: Organized collection of macrophages designed to wall off a foreign body or infectious pathogen that cannot be eliminated. Gummatous: A small, soft swelling that is characteristic of the late stages of syphilis and generally occurs in the connective tissue of the liver, brain, testes, and heart. Gut-associated lymphoid tissue: Lymphoid tissue, including Peyer patches, found in the gut that are important for providing localized immunity to pathogens. Guttate psoriasis: Characterized by a heavy or light sprinkling of teardrop-like, salmon-pink papules covered with a fine scale. These lesions are found primarily on the trunk and proximal extremities. Gynecomastia: Excessive development of the breasts in males. HACEK: Group of fastidious gram-negative bacteria consisting of Haemophilus spp., Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae. Hashimoto Disease: Condition in which the immune system attacks the thyroid gland; may result in hypothyroidism. Symptoms may include fatigue, weight gain, pale or puffy face, feeling cold, joint and muscle pain, constipation, dry and thinning hair, heavy menstrual flow or irregular periods, depression, a slowed heart rate, and problems getting pregnant and maintaining pregnancy. It occurs more commonly in women than in men. Health literacy: Degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions. Heberden nodes: Hard, bony enlargement of the distal interphalangeal (terminal) joint of a finger or toe. Hematemesis: Vomiting blood from gastric or esophageal bleeding; in cirrhosis this is caused by variceal bleeding. Hematochezia: Passage of stool that is bright red or maroon, usually because of bleeding from the lower gastrointestinal tract. Hematogenous: Spread of infection via the blood stream. Hematoma: A localized swelling in an organ or soft tissue that is filled with clotted or partially clotted blood resulting from a break in a blood vessel wall. Hemiparesis: Weakness on one side of the body. Hemisensory deficit: Loss of sensation on one side of the body. Hemithorax: A single side of the trunk between the neck and the abdomen in which the heart and lungs are situated. Hemoptysis: The expectoration of blood or blood-tinged sputum from the larynx, trachea, bronchi, or lungs. Heparin-induced thrombocytopenia: A clinical syndrome of IgG antibody production against the heparin-platelet factor 4 complex occurring in approximately 1% to 5% of patients exposed to either heparin or low-molecular weight heparin. Results in excess production of thrombin, platelet aggregation, and thrombocytopenia (due to platelet clumping), often leading to venous and arterial thrombosis, amputation of extremities, and death. Hepatic encephalopathy: Confusion and disorientation experienced by patients with advanced liver disease due to accumulation of ammonia in the bloodstream. Hepatic steatosis: Accumulation of fat in the liver. Hepatocellular carcinoma: Cancer of the liver. Hepatorenal syndrome: Acute kidney injury occurring in individuals with disease of the liver or biliary tract due to decreased renal blood flow and conditions that damage both organs. Hepatotoxicity: Toxicity to the liver causing damage to liver cells. Herd immunity: The resistance to the spread of a contagious disease within a population, if a sufficiently high proportion of the people are immune to the disease, such as through vaccination. Herniation: Abnormal protrusion of an organ or other structure through a defect or natural opening in a covering, membrane, muscle, or bone (eg, protrusion of the brain through the cranial wall). Hesitancy: A decrease in the force of the stream of urine usually the result of an obstruction or stricture between the bladder and the external urethral orifice. Heteroreceptor: A site on a neuron that binds a neurotransmitter other than that released by the neuron. Heterotopic: Placing a transplanted organ into an abnormal anatomic location. Heterozygous: Having different alleles at a gene locus. Hiatal hernia: Protrusion of a portion of the stomach through the esophageal hiatus of the diaphragm. Hirsutism: Excessive body and facial hair, especially in the female. Histocompatibility: State of having antigenic similarities that prevent donor hematopoietic stem cells from being rejected by the recipient. Homeostenosis: Impaired capability to withstand stressors and decreased ability to maintain physiological and psychosocial homeostasis; a state commonly found in elderly.