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Estrous Cycle
The order of the Estrous Cycle
Part 1 | Part 2 |
---|---|
Brain initiates the cycle | The release of GnRH causes the release of FSH |
FSH is carried to ovaries where it causes the growth of selected ovarian follicles | Follicles produce estrogen and inhibin |
Inhibin causes only species specific number of follicles to mature by inhibiting further release of FSH | Estrogen stimulates GnRH to stimulate the release of LH causing the mature follicle to ovulate |
The follicle transforms CL in the oviduct | The CL produces progesterone to maintain pregnancy |
Fertilization occurs and pregnancy begins | Early embryo signals uterus and ovary that pregnancy is established |
If egg is not fertilized, the CL continues to develop and maintains progesterone production (This is called diestrus) | The uterus releases prostaglandin if it doesn't receive the embryo signal. |
Prostagliandin lyses the CL causing a decrease in progesterone and ending diestrus | Follicle growth (would continue without progesterone) after the death of CL is called proestrus and the cycle repeats. |