4,503
edits
Changes
Oestrous Cycle - Anatomy & Physiology (view source)
Revision as of 09:19, 11 September 2008
, 09:19, 11 September 2008→Cyclic Changes in the Ovaries
* There is rapid development of the corpus luteum.
* There is rapid development of the corpus luteum.
** Development is linear from day 2-12 after ovulation.
** Development is linear from day 2-12 after ovulation.
*
* By day 5 of dioestrus, the corpus luteum is 0.6cm in diameter.
* It then attains a maximum size of 0.9cm diameter and has a central cavity.
* Over the period of dioestrus, the colour changes from blood red to pale pink. The size stays constant until the onset of th next oestrus.
* At the onset of the next oestrus:
** Regression of the corpus luteum of the previous cycle is rapid
** Colour changes to yellow and then brownish-yellow.
* The luteolytic mechanism is similar to in the cow.
** At the end of dioestrus, under the influence of oestradiol and progesterone, there is an increase in the number of uterine oxytocin receptors.
** At the same time, the corpus luteum produces oxytocin, which stimulates PGF2. PGF2 then acts to stimulate the release of oxytocin in a feedback loop mechanism.
=== Endocrine Changes during the Oestrous Cycle ===
=== Endocrine Changes during the Oestrous Cycle ===