Learn about this topic in these articles:

animal reproduction
- In animal reproductive system: Ovaries
  …time or another, eggs in ovarian follicles (i.e., developing eggs); it undergoes fluctuations in size and appearance that correlate with stages of the reproductive cycle. The cortex also contains remnants of ovulated follicles and, in mammals, clusters of interstitial cells that, in some species, are glandular. The cortical components are…
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discovery by Graaf
- In Reinier de Graaf
  …of the ovary (known as Graafian follicles), in which the individual egg cells are formed. He was also important for his studies on the pancreas and on the reproductive organs of mammals.
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human reproduction
- In human reproductive system: Ovarian structure
  The ovarian follicles, sometimes called graafian follicles, are rounded enclosures for the developing ova in the cortex near the surface of the ovary. At birth and in childhood they are present as numerous primary or undeveloped ovarian follicles. Each contains a primitive ovum, or oocyte, and…
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- In menstruation: Biological significance
  …hormones that induce ripening of ovarian follicles—ova and the cellular structures that enclose them. These pituitary hormones, called gonadotropic hormones, are carried to the ovaries by way of the bloodstream. In primates the hypothalamic mechanism normally is independent of external stimuli, and regular discharge of ova into the tubes leading…
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In hormone: Follicle-stimulating hormone
FSH stimulates development of the graafian follicle, a small vesicle containing an egg, in the ovary of the female mammal. In the male it promotes the development of the tubules of the testes and the differentiation of sperm. FSH, like thyrotropin, is a glycoprotein, with an estimated molecular weight (in…
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In hormone: Estrogens
…the mammalian ovary by the ovarian follicle, or vesicle, including the granulosa cells immediately surrounding the ovum, or egg, and the cells of the theca, which forms a supporting outer wall for the follicle. The main estrogen secreted is called β-estradiol. The close relationship between the female and the male…
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follicle-stimulating hormone
- In follicle-stimulating hormone
  …(LH), stimulates development of the graafian follicle, a small, egg-containing vesicle in the ovary of the female mammal; in the male, it promotes the development of the tubules of the testes and the differentiation of sperm. Though in the male the presence of FSH is necessary for the maturation of…
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luteinizing hormone
- In luteinizing hormone
  …promotes the transformation of the graafian follicle (a small egg-containing vesicle in the ovary) into the corpus luteum, an endocrine gland that secretes progesterone. In the male, LH stimulates the development of the interstitial cells of the testes, which secrete testosterone, a male sex hormone. The production of LH is…
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