Changes

== Mammogenesis ==

== Mammogenesis ==

* Build up to peak yield, then a decline as the offspring requirement diminishes.

* Build up to peak yield, then a decline as the offspring requirement diminishes.

* Depends on the frequency of suckling stimulus to cause release of the lactogenic complex.

* Depends on the frequency of suckling stimulus to cause release of the lactogenic complex.

== Milk Ejection Reflex ==

== Milk Ejection Reflex ==

* '''[[Endocrine_System_-_Pituitary_Gland_-_Anatomy_%26_Physiology#Oxytocin|Oxytocin]]''' is synthesised by magnocellar neurones of the '''Paraventricular nucleus (PVN)''' and '''Supraoptic nucleus (SON)''' of the '''[[Endocrine_System_-_Hypothalamus_-_Anatomy_%26_Physiology#Hypothalamus|Hypothalamus]] '''.

* '''[[Pituitary Gland - Anatomy_%26_Physiology#Oxytocin|Oxytocin]]''' is synthesised by magnocellar neurones of the '''Paraventricular nucleus (PVN)''' and '''Supraoptic nucleus (SON)''' of the '''[[Hypothalamus_- Anatomy & Physiology#Hypothalamus|Hypothalamus]] '''.

* Oxytocin is secreted from the '''[[Endocrine_System_-_Pituitary_Gland_-_Anatomy_%26_Physiology#Posterior_Pituitary_Gland|Posterior Pituitary Gland]]'''.

* Oxytocin is secreted from the '''[[Pituitary_Gland_- Anatomy & Physiology#Posterior_Pituitary_Gland|Posterior Pituitary Gland]]'''.

* Plasma oxytocin concentration rises rapidly following suckling stimulation via a '''neuroendocrine reflex''' and exibit '''positive feedback'''.  The positive feedback loop is terminated when stimulation of the teat ceases.

* Plasma oxytocin concentration rises rapidly following suckling stimulation via a '''neuroendocrine reflex''' and exibit '''positive feedback'''.  The positive feedback loop is terminated when stimulation of the teat ceases.

*  The neuroendocrine reflex may become a conditioned behavioural reflex, such that a cow going to the milking parlour will have elevated levels of oxytocin in the plasma prior to stimulus being applied to the teats.

*  The neuroendocrine reflex may become a conditioned behavioural reflex, such that a cow going to the milking parlour will have elevated levels of oxytocin in the plasma prior to stimulus being applied to the teats.

* Oxytocin exibits a local positive feedback effect in the hypothalamus to trigger maternal behaviour and the maternal bonding process.  Hence stimulating the cervix of a foster ewe to trigger the Fergessons reflex and thus trigger oxytocin release makes accepting the orphaned lamb more likely.

* Oxytocin exibits a local positive feedback effect in the hypothalamus to trigger maternal behaviour and the maternal bonding process.  Hence stimulating the cervix of a foster ewe to trigger the Fergessons reflex and thus trigger oxytocin release makes accepting the orphaned lamb more likely.