1,240 articles
End-plate potential
End-plate potential (EPP), the graded depolarization of skeletal muscle at the neuromuscular junction, produced by acetylcholine release; built from about 200 quantal units (MEPPs, first recorded by Fatt and Katz), triggers the muscle action potential unless reduced, as in myasthenia gravis.
Endocochlear potential and cochlear homeostasis
Endocochlear potential (EP), the ~+80 mV positive potential of cochlear endolymph generated by the stria vascularis via Kir4.1 channels, drives hair-cell transduction; its maintenance through potassium recycling defines cochlear homeostasis.
Endophthalmitis
Endophthalmitis: purulent intraocular inflammation of vitreous and aqueous, usually infectious; exogenous or endogenous. Treated with intravitreal vancomycin and ceftazidime, with vitrectomy guided by the 1995 EVS trial.
Endorphins
Endorphins are endogenous opioid peptides, chiefly beta-endorphin from POMC, binding mu and other opioid receptors; discovered after the 1975 enkephalin finding, they modulate pain, reward, stress, and exercise effects.
Enteric nervous system
Enteric nervous system (ENS), the gut's "second brain": intrinsic network of over 500 million neurons and glia in the gastrointestinal wall, forming myenteric and submucosal plexuses, controlling motility and secretion autonomously of the CNS.
Enteric neuron
Enteric neuron, a neuron of the enteric nervous system ("second brain"), located in myenteric and submucosal plexuses; sensory, interneuron, motor, and secretomotor types operating largely independently of the CNS.
Entoptic phenomenon
Entoptic phenomenon: visual sensations arising inside the eye itself, including floaters, blue field entoptic phenomenon (Scheerer phenomenon), Haidinger's brushes, and the Purkinje tree; used clinically to measure macular blood flow.
Entorhinal cortex
The entorhinal cortex is a medial temporal lobe region acting as the gateway between the hippocampus and neocortex, central to memory and containing grid cells for navigation.
Enucleation of the eye
Enucleation of the eye is surgical removal of the entire globe, unlike evisceration (contents only) or exenteration (whole orbit). First documented by Bartisch in 1583; used for intraocular malignancy, blind painful eye, and trauma, usually with an orbital implant and later prosthesis.
Ependyma
Ependyma: ciliated simple cuboidal epithelium (ependymocytes, tanycytes, choroid plexus) lining brain ventricles and spinal central canal; radial-glia derived glia driving CSF flow at 28–40.7 Hz, partial CSF–brain barrier, ependymoma origin.
Ependymoma
Ependymoma, also known as ependymal tumor, is a glioma arising from ependymal cells lining the brain's ventricles and spinal canal, treated with surgery and radiation.
Ephrin
Ephrins are membrane-bound ligands of Eph receptor tyrosine kinases, the largest RTK family, split into GPI-anchored ephrin-A and transmembrane ephrin-B classes mediating bidirectional signaling in axon guidance and cancer.
Epiblepharon
Epiblepharon is a congenital eyelid condition, common in East Asian children, in which a skin-muscle fold overrides the lower lid margin and turns lashes against the eye; it often resolves spontaneously and is corrected by the modified Hotz procedure.
Epibulbar choristoma
Epibulbar choristoma (ICD-11 LA14.06): benign congenital growth of normal tissue in an abnormal site on the eye surface; types include dermoid, dermolipoma, complex, and the rare osseous choristoma containing bone.
Epicanthic fold
Epicanthic fold (epicanthal fold, epicanthus, plica palpebronasalis): a skin fold of the upper eyelid covering the eye's inner corner. Normal in East Asians (40–90%) and children; also seen in Down syndrome and BPES; corrected by epicanthoplasty.
Epidural administration
Epidural administration injects local anesthetics or opioids into the epidural space between dura mater and vertebral canal. Pioneered by Corning (1885), Sicard and Cathelin (1901), and Fidel Pagés (1921); used for labor, surgery, and postoperative pain.
Epidural hematoma
Epidural hematoma (EDH, extradural hematoma): blood between skull and dura, usually from middle meningeal artery tear after skull fracture. Biconvex on CT, lucid interval in under 20%, surgery if over 30 cm3 per Brain Trauma Foundation.
Epilepsy research
Epilepsy Research (Epilepsy Res., ISSN 0920-1211) is an Elsevier peer-reviewed journal, published in Amsterdam since 1987, covering basic, clinical, and translational epilepsy research across disciplines.
Epiretinal membrane
Epiretinal membrane (macular pucker): fibrocellular sheet on the inner retinal surface, usually after posterior vitreous detachment, causing metamorphopsia; staged by Govetto OCT criteria, observed or treated by vitrectomy with membrane and ILM peeling.
Episcleritis
Episcleritis, also called bulbar conjunctivitis, is a benign, self-limited inflammation of the episclera between conjunctiva and sclera, with simple and nodular forms, usually idiopathic, sometimes linked to rheumatoid arthritis or IBD, and distinguished from scleritis by phenylephrine blanching.
Episodic memory
Episodic memory is the memory system for personally experienced events, tied to the time and place they occurred. Endel Tulving defined it in 1972 as distinct from semantic memory.
Epley maneuver
The Epley maneuver, also called the canalith repositioning procedure, is a sequence of timed head and body positions used to treat benign paroxysmal positional vertigo.
Erb's palsy
Erb paralysis (Erb's palsy, Erb-Duchenne paralysis) is upper-arm weakness from C5–C6 upper trunk brachial plexus injury, mostly at birth; ~90% of neonatal brachial plexus palsies, often with shoulder dystocia, usually recovering in 3–4 months.
Esotropia
Esotropia, also known as cross-eye or convergent strabismus, is a form of strabismus in which one eye deviates inward toward the nose, affecting about 0.67% of people worldwide.
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.