Category: L

  • Leukoencephalitis

    Inflammation of the white matter of the brain.  

  • Lethal dose

    Amount of a drug that will cause death. The dose of a substance that results in the death of cells, tissues, or the organism.  

  • Leptons

    One of the two groups of matter particles. There are six types of leptons, all exist in pairs, each pair consisting of an electrically charged particle and a neutrino. The best-known pair is the electron and the electron neutrino. Leptons are subject to the electromagnetic and weak interactions.  

  • Leper

    Person who has leprosy.  

  • Latent schizophrenia

    Form of schizophrenia characterized by mild symptoms and/or a preexisting tendency to the disease in its usual form; also called borderline schizophrenia.  

  • Latency phase

    In psychoanalytic theory, the fourth stage in a person’s development, generally between the ages of 6 and puberty, during which the sex drive is not active, but is sublimated into other activities.  

  • Landmark

    Recognizable anatomic structure used as a reference point to measure or describe physical findings or other anatomic structures. A recognizable skeletal or soft tissue structure used as a reference point in measurements or in describing the location of other structures. Within the realm of superficial anatomy, a distinctive anatomical attribute that manifests visibly on the…

  • Lambdacism

    Speech disorder marked by incorrect or excessive pronunciation of the sound “1” or substitution of the sound ‘Y’ for “1”.  

  • Lallation

    Unintelligible speech-like utterances, as the babbling of an infant. An infantile form of speech in which the letter “1” is incorrectly used or pronounced.  

  • Lagophthalmos

    Abnormal condition in which an eye cannot be closed completely, because of disorder of the cornea or neurological or muscular disorder. Any condition in which the eye does not close completely. It may lead to corneal damage from undue exposure. An incomplete closure of the palpebral fissure when an attempt is made to shut the…