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Oestrous Cycle - Anatomy & Physiology (view source)
Revision as of 14:45, 10 September 2008
, 14:45, 10 September 2008→Headline text
* In addition, pathological structures like ovarian cysts can be seen.
* In addition, pathological structures like ovarian cysts can be seen.
== Headline text ==
=== Endocrine Changes during the Oestrous Cycle ===
* Hormones are secreted in a pulsatile manner and fluctuate considerably.
* Just before onset of behavioural oestrus, there is a sharp rise in plasma oestrogens, particularly oestradiol.
** Peak values occur at the beginning of oestrus
** Levels decline to basal concentrations at ovulation
* During the rest of the cycle, there are fluctuations but there is a discrete peak around day 6 of the cycle.
** Related to the first wave of follicular growth
* Pre-oestrus rise in oestrogens stimulates the LH surge from the anterior pituitary.
** This is necessary for follicular maturation, ovulation and maturation of the corpus luteum.
* A second, less discrete peak occurs 24 hours after the LH surge.
* Changes in progesterone concentrations mimic changes in the corpus luteum.
* Progesterone levels peak 7-8 days after ovulation and decline quickly from day 18.
* When progesterone levels fall to low basal levels, the negative feedback on the pituitary gland is removed. This allows a sudden release of gonadotrophins.
= Links =
= Links =
[[Oestrous_Cycle_-Pharmacological_Manipulation_of_Oestrous_Cycles_-_Anatomy_%26_Physiology|Pharmacological Manipulation of Oestrous Cycles]]
[[Oestrous_Cycle_-Pharmacological_Manipulation_of_Oestrous_Cycles_-_Anatomy_%26_Physiology|Pharmacological Manipulation of Oestrous Cycles]]