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Oestrous Cycle - Anatomy & Physiology (view source)
Revision as of 11:21, 11 September 2008
, 11:21, 11 September 2008→Cyclic Changes in the Ovaries
* Immediately after ovulation, the ruptured follicle is seen as a congested depression on the ovary.
* Immediately after ovulation, the ruptured follicle is seen as a congested depression on the ovary.
* Accumulation of blood clot soon gives the ruptured follicle a conical shape.
* Accumulation of blood clot soon gives the ruptured follicle a conical shape.
* By day 3 after ovulation, its cavity is filled with a dark red blood clot.
* By day 6, the blood clot is replaced by a connective tissue plug, or slightly yellow fliud.
** Clots may persist up to day 12.
** Fluid may persist up to day 18.
* Corpora lutea attain maximum size at 12-15 days post-ovulation.
* After this, they gradually regress to the next oestrus.
* They are dark red up to day 3.
* They then change colour and remain 'wine red' up to day 15.
* As the corpus luteum regresses between days 15-18, the colour rapidly changes to yellow, creamy yellow or buff.
* The mechanism of luteolysis is not fully understood in the sow.
** Corpora lutea are unresponsive to PGF2
=== Endocrine Changes during the Oestrous Cycle ===
=== Endocrine Changes during the Oestrous Cycle ===