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graafian follicle

a small pouchlike cavity in an ovary in which an ovum develops (see oogenesis). At ovulation, one of the follicles ruptures and releases a mature ovum into a fallopian tube, where it may be fertilized. The ruptured follicle becomes the site of the corpus luteum. Also called ovarian follicle. [Reijner de Graaf (1641–1673), Dutch histologist]

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Psychology term of the day

May 26th 2024

metachromatic leukodystrophy

metachromatic leukodystrophy

an autosomal recessive disorder (see recessive allele) characterized by deficiency or absence of the enzyme arylsulfatase A, which results in loss of myelin in the nervous system and accumulation of cerebroside sulfate (a type of myelin lipid) within the white matter of the central nervous system. Loss of motor function and deterioration in mental ability most commonly develop after the 1st year of life (late infantile form), but symptoms may also appear between 3 and 10 years of age (juvenile form) or around age 30 (adult form).