Appearance
It is marked by the formation of a fluid-filled cavity adjacent to the oocyte called the antrum. The basic structure of the mature follicle has formed and no novel cells are detectable. Granulosa and theca cells continue to undergo mitosis concomitant with an increase in antrum volume. Antral follicles can attain a tremendous size that is hampered only by the availability of follicle stimulating hormone (FSH), which it is dependent on in this stage of folliculogenesis.
By command of an oocyte-secreted morphogenic gradient, the antral follicle's granulosa cells begin to differentiate themselves into four distinct subtypes: corona radiata that surrounds the zona pellucida, membrana that's interior to the basal lamina, periantral that's adjacent to the antrum, and cumulus oophorous that connects the membrana and corona radiata granulosa cells together. Each type of cell behaves differently in response to FSH.
Read more about this topic: Antral Follicle
Famous quotes containing the word appearance:
“The President has paid dear for his White House. It has commonly cost him all his peace, and the best of his manly attributes. To preserve for a short time so conspicuous an appearance before the world, he is content to eat dust before the real masters who stand erect behind the throne.”
—Ralph Waldo Emerson (1803–1882)
“This mesa plain had an appearance of great antiquity, and of incompleteness; as if, with all the materials for world-making assembled, the Creator had desisted, gone away and left everything on the point of being brought together, on the eve of being arranged into mountain, plain, plateau. The country was still waiting to be made into a landscape.”
—Willa Cather (1873–1947)
“Most lovers ... picture to themselves, in their mistresses, a secret reality, beyond and different from what they see every day. They are in love with somebody else—their own invention. And sometimes there is a secret reality; and sometimes reality and appearance are the same. The discovery, in either case, is likely to cause a shock.”
—Aldous Huxley (1894–1963)