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Parturition Endocrine Control - Anatomy & Physiology (view source)
Revision as of 09:30, 9 July 2008
, 09:30, 9 July 2008no edit summary
== Introduction ==
The foetus triggers the onset of parturition by initiating a cascade of complex endocrine/biochemical events. The foetal hypothalamo-pituitary-adrenal axis is obligatory for the initiation of parturition.
== Regulation of Prostaglandins ==
The [[Female_Reproductive_Tract_-The_Uterus|uterus]] is an important site of prostaglandin synthesis. During pregnancy, the presence of the foetus inhibits the production of prostaglandins in order to prevent luteolysis. At parturition, an increase in prostaglandin synthesis is required.
The [[Female_Reproductive_Tract_-The_Uterus|uterus]] is an important site of prostaglandin synthesis. During pregnancy, the presence of the foetus inhibits the production of prostaglandins in order to prevent luteolysis. At parturition, an increase in prostaglandin synthesis is required.
== Regulation of Oxytocin ==
Details of Oxytocin Synthesis and Secretion may be found [[Endocrine_System_-_Pituitary_Gland_-_Anatomy_%26_Physiology#Oxytocin|here]]
Details of Oxytocin Synthesis and Secretion may be found [[Endocrine_System_-_Pituitary_Gland_-_Anatomy_%26_Physiology#Oxytocin|here]]
== Onset of Parturition ==
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''Species that depend on the Corpus Luteum to produce progesterone throughout pregnancy (Goat, Cow, Sow, Bitch)''
'''''Species that depend on the Corpus Luteum to produce progesterone throughout pregnancy (Goat, Cow, Sow, Bitch)'''''
* The foetus initiates parturition.
* The foetus initiates parturition.
* For parturition to occur, progesterone production by the Corpus Luteum must be terminated.
* For parturition to occur, progesterone production by the Corpus Luteum must be terminated.
''Species that depend on Placental Progesterone in late pregnancy (Ewe,Guinea Pig,Queen,Mare)''
'''''Species that depend on Placental Progesterone in late pregnancy (Ewe,Guinea Pig,Queen,Mare)'''''
* As previously explained, parturition is dependent on a rise in foetal Cortisol. However, in this case, the rise in foetal cortisol leads to a decrease in '''maternal''' Progesterone.
* As previously explained, parturition is dependent on a rise in foetal Cortisol. However, in this case, the rise in foetal cortisol leads to a decrease in '''maternal''' Progesterone.
* Foetal Cortisol causes upregulation of the enzymes '''17α Hydroxylase, C17-C20-lyase and Aromatase''' in order to increase the Oestrogen:Progesterone ratio.
* Foetal Cortisol causes upregulation of the enzymes '''17α Hydroxylase, C17-C20-lyase and Aromatase''' in order to increase the Oestrogen:Progesterone ratio.