Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «L»:
Lennox-Gastaut syndrome: A severe form of epilepsy that
is characterized by the onset in early childhood of frequent seizures of multiple types, developmental delay, a particular brain wave pattern (a slow spike-and-wave pattern), and behavioral disturbances with poor social skills and attention-see...
Lens: The transparent structure inside the eye
that focuses light rays onto the retina (the nerve layer
that lines the back of the eye, senses light and creates
impulses that go through the optic nerve to the brain). The
lens was named after the lentil bean because it resembled
it in shape and ...
Lens, intraocular: See: Intraocular lens....
Lens, objective: In a microscope, the objective lens is the lens nearest to the object being examined whereas the lens closest to the eye is termed the ocular (the eyepiece).
The light microscope today is usually binocular (with one ocular for each eye) and has a turret bearing a selection of object...
Lens, ocular: In a microscope, the lens closest to the eye is termed the ocular (the eyepiece) whereas the objective (also called the objective lens) is the lens nearest to the object being examined.
The light microscope today is usually binocular (with one ocular for each eye) and has a turret bear...
Lentigines: When there is one lentigo, there are usually more lentigines....
Lentiginosis profusa syndrome
Lentiginosis profusa syndrome: See: LEOPARD syndrome....
Lentigo: A type of freckle that is a small tan, brown, or black spot which tends to be darker than the usual (ephelis-type) freckle and which do not fade in the winter. This kind of spot is referred to as lentigo simplex. Although lentigines may be part of a genetic disorder, for the most part they ...
Lentigo maligna melanoma
Lentigo maligna melanoma: See: Melanoma, lentigo maligna....
Lentigo, senile: See: Senile lentigo....
Lenz microphthalmia syndrome
Lenz microphthalmia syndrome: A genetic disorder characterized by microphthalmia (small eye) or anopthalmia (no eye) associated with malformation of the ears, teeth, fingers, skeleton, and genitourinary system. About half of patients have microcephaly (small head) and mental retardation.
Leon virus: Type 3 poliovirus. Named after the patient in California from whom this virus was first isolated. There are two other strains of poliovirus: Type 1 (known as the Brunhilde virus) and Type 2 (known as the Lansing virus). Immunity to one strain does not provide protection against the other...
Leonardo da Vinci
Leonardo da Vinci: Architect, engineer,
inventor, painter and the father
of anatomic art. Leonardo da Vinci first became interested
when he was asked by a Veronese anatomist named Marc
Antonia Della Torre to do the illustrations
for a text of anatomy. Della Torre was to do the
dissecting and ...
LEOPARD syndrome: A genetic syndrome transmitted in an autosomal dominant manner that is named for its characteristic features:
L -- lentigines (dark freckles) on the head and neck
E -- electrocardiogram (EKG) abnormalities
O -- ocular hyperteleorism (wide-spacing of the eyes)
P -- pulmonary sten...
Leper: 1. Someone with leprosy (Hansen disease). The term leper is now in disfavor.
2. By extension, a pariah. A person who is avoided or shunned by society.
From the French lepre, from the Greek lepros meaning scaly, referring to the scales that form on the skin in some cases of leprosy....