2,701 articles
Estrogen
Estrogen: collective term for the female sex hormones estradiol (E2), estrone (E1), and estriol (E3), steroid hormones made from androgens by aromatase. Purified 1929 by Doisy and Butenandt; acts via ERα, ERβ, GPER1; basis of contraception and menopausal hormone therapy.
Estrogen in Venous Thromboembolism Trial
Estrogen in Venous Thromboembolism Trial (EVTET), Norwegian randomized double-blind placebo-controlled trial (Høibraaten et al., 2000) of 2 mg estradiol plus 1 mg norethisterone acetate in 140 women with prior VTE; stopped early after 10.7% versus 2.3% recurrence.
Ethmoid bone
Ethmoid bone (os ethmoidale), unpaired midline cranial bone between the orbits; forms upper nasal septum, nasal cavity roof, medial orbit wall; consists of cribriform plate, perpendicular plate, two labyrinths with ethmoid air cells.
European Association for Cardio-Thoracic Surgery
The European Association for Cardio-Thoracic Surgery (EACTS) is a professional association for cardiothoracic surgeons and perfusionists, founded in 1986 by Francis Fontan and headquartered in Windsor, United Kingdom.
European Heart Journal
European Heart Journal (EHJ), flagship peer-reviewed cardiology journal of the European Society of Cardiology, launched 1980, published by Oxford University Press; 2025 impact factor 43.5, ranked 2/237 in Cardiac & Cardiovascular Systems; publishes ESC Guidelines.
European Society of Cardiology Distinguished Fellow designation
The European Society of Cardiology Distinguished Fellow designation is the honorary title Fellow of the European Society of Cardiology (FESC), introduced in 1988 and now held by over 4,300 professionals.
Eustachian salpingitis
Eustachian salpingitis (otosalpingitis, tubotympanitis) is inflammation of the Eustachian tube, ICD-11 AB10.2 and ICD-10 H68.0, causing ear pressure, soreness, and reduced hearing, usually after respiratory infection or allergy.
Eustachian tube
Eustachian tube (auditory, pharyngotympanic tube): passage linking middle ear to nasopharynx, named for Bartolomeo Eustachi. Ventilates, clears, and protects the middle ear; dysfunction subtypes are dilatory, baro-challenge-induced, and patulous.
Evolution of color vision
Evolution of color vision: how opsin gene duplications and losses shaped animal color vision, from four-cone ancestral vertebrates through the nocturnal mammalian bottleneck to primate trichromacy regained about 35 million years ago.
Excitatory postsynaptic potential
Excitatory postsynaptic potential (EPSP), a depolarizing postsynaptic potential that increases action potential likelihood; distinguished from IPSP by a reversal potential above spike threshold; mediated by glutamate receptors such as AMPA.
Executive dysfunction
Executive dysfunction is impaired ability to manage thoughts, emotions, and actions, seen in ADHD, addictions, depression, brain injury, and dementia. Core deficits involve inhibition, working memory, and cognitive flexibility; treated via the underlying condition.
Executive functions
Executive functions: top-down cognitive processes (inhibition, working memory updating, set shifting) controlling goal-directed behavior, prefrontal-network based, impaired in ADHD and dementia, assessed by tests, rating scales, and VR.
Exercise intolerance
Exercise intolerance is a reduced ability to perform physical activity, limited by dyspnea, fatigue, or leg discomfort. Causes include heart failure (about 50% of the 6 million U.S. patients), COPD, anemia, and Long COVID; CPET is the gold-standard assessment.
Exercise Tolerance
Exercise tolerance: an individual's exercise capacity measured as maximal exercise duration or work load during an exercise test; assessed by CPET (gold standard), graded stress tests, or six-minute walk, and a strong prognostic marker.
Exhalation
Exhalation (respiratory expiration): the act of breathing out. Passive at rest via lung elastic recoil; active via internal intercostals and abdominals during exercise; expiratory flow limitation causes dynamic hyperinflation in COPD.
Exocrine gland
An exocrine gland, known in Latin as glandula exocrina, releases substances such as sweat, tears, saliva, milk, and digestive juices through a duct onto a body surface.
Exophthalmos
Exophthalmos, also called proptosis, is the bulging of one or both eyes from the orbit, the bony socket. In adults it is most often caused by Graves disease.
Exotropia
Exotropia, also called wall-eye, is an outward-turning eye misalignment (strabismus). Most common form is intermittent exotropia (75-90% of cases, ~1% prevalence); treated with patching, overminus lenses, or eye muscle surgery.
Expiratory Reserve Volume
Expiratory reserve volume (ERV) is the maximal air exhaled from functional residual capacity to residual volume; one of four lung volumes, spirometry-measured, and reduced earliest and most markedly in obesity, supine posture, and pregnancy.
Exposure keratitis
Exposure keratitis (exposure keratopathy, EK): corneal damage from dryness due to incomplete eyelid closure or poor blinking. Common in ICU patients (pooled prevalence 34%); treated with lubricants, moisture chambers, taping, tarsorrhaphy.
Exsanguination
Exsanguination, also called exsanguinating hemorrhage or total blood loss, is rapid extreme blood loss leading to hemorrhagic shock; it causes nearly half of early trauma deaths and is treated with damage-control resuscitation.
External carotid artery
External carotid artery (ECA): artery from the common carotid bifurcation (about C3-C4) supplying head and neck structures outside the skull; eight variable branches, common trunks, embolization and collateral pathways.
Extracellular fluid
Extracellular fluid (ECF), all body water outside cells, about one third of body fluid volume, divided into interstitial fluid, plasma, and transcellular fluid; sodium-dominated, osmolality 280-295 mOsm/kg, regulated by vasopressin, thirst, and the renin-aldosterone system.
Extrafusal muscle fiber
Extrafusal muscle fibers are the ordinary force-generating skeletal muscle fibers outside the muscle spindles, innervated by alpha motor neurons in motor units, arranged in parallel with intrafusal spindle fibers, and typed I, IIa, IIb, IIx.
Extramedullary hematopoiesis
Extramedullary hematopoiesis is the production of blood cells outside the bone marrow, mainly in the spleen, liver, and lymph nodes, often compensating for marrow failure.
Extraocular muscles
Extraocular muscles: the seven muscles per orbit (four rectus, two oblique, levator palpebrae superioris) that move the eye and lift the eyelid, innervated by cranial nerves III, IV, and VI, organized in global and orbital layers with connective tissue pulleys.
Extrapyramidal system
Extrapyramidal system: historical grouping of basal ganglia, substantia nigra, red nucleus, subthalamic nucleus and descending tracts outside the corticospinal tract; criticized as obsolete, tied to antipsychotic EPS, VMAT2 inhibitor treatments.
Eye
Eye: the organ that focuses light through cornea, pupil, and lens onto the retina, sending signals via the optic nerve to the brain; camera eyes evolved convergently in vertebrates and cephalopods, and vision impairment affects over 2.2 billion people.
Eye Axial Length
Eye axial length: distance from cornea to retina, normally about 23.5 mm (22-24.5 mm). Longer in myopia, shorter in hyperopia; measured by A-scan ultrasound or optical biometry (PCI, SS-OCT) for IOL calculation and myopia control.
Eye discharge
Eye discharge (eye mucus, ICD-11 MC14): mucus, pus, or excess tears from the eye. Normal as sleep crust; abnormal color, texture, or amount signals conjunctivitis, keratitis, blepharitis, stye, or dry eye.