
Histology of the preovulatory follicle
A 'granulosa cell' is a somatic cell found closely associated with the developing female
gamete (called an
oocyte or egg) in the
ovary of
mammals.
Anatomy and function
Granulosa cells form a single flattened layer around the mammalian
oocyte in the primary ovarian
follicle and later in follicle development (
folliculogenesis) they advance to form a multilayered
cumulus oophorus surrounding the
oocyte in the preovulatory or
Graafian follicle.
The major functions of granulosa cells include the production of
steroids, as well as a myriad of growth factors thought to interact with the
oocyte during its development.
Also FSH stimulates granulosa cells to convert
androgens (coming from the
thecal cells) to
estradiol by
aromatase.
Embryology of ovarian granulosa cells
In the
development of the urinary and reproductive organs, the
oogonia become invaginated in the
gonadal ridge.
In the 1970’s, evidence emerged that the first cells to make contact with the oogonia were of mesonephric origin.
It was suggested that mesonephric cells already closely associated with the
oogonia proliferated throughout development to form the granulosa cell layer.
[1][2][3]
Recently this hypothesis has been challenged with some thorough histology. Sawyer et al. hypothesised that in sheep most of the granulosa cells develop from cells of the
mesothelium (i.e., epithelial cells from the presumptive surface epithelium of the ovary).
[4]
The embryological origin of granulosa cells remains controversial.
Additional images
References
1. Histogenesis and organogenesis of the gonad in human embryos., Satoh M, , , J Anat,
2. Preliminary observations on the role of the mesonephros in the development of the adrenal cortex., Upadhyay S, Zamboni L, , , Anat Rec, 1982
3. Zamboni, L., Bezard, J., and Mauleon, P. (1979). The role of the mesonephros in the development of the sheep fetal ovary. Annales de Biologie Animal Biochimie et Biophysique 19, 1153-78.
4. Formation of ovarian follicles during fetal development in sheep., Sawyer H, Smith P, Heath D, Juengel J, Wakefield S, McNatty K, , , Biol Reprod, 2002
See also
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Granulosa cell tumour
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Ovulation
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Membrana granulosa
External links
★ - "Female Reproductive System: ovary, cumulus oophorus"
★ - "Female Reproductive System: ovary, membrana granulosa"
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