Changes

<big><center>[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]</center></big>

 

<big><center>[[Reproductive_System#Lactation|'''BACK TO LACTATION''']]</center></big>

|linkpage =Reproductive System - Anatomy & Physiology

 

|linktext =Reproductive System

 

 

 

|sublink1=Reproductive System - Anatomy & Physiology#Lactation

 

|subtext1=LACTATION

<br>

== Mammogenesis ==

== Mammogenesis ==

* '''Prolactin''' and '''progesterone''' are important for lobular alveolar growth.

* '''Prolactin''' and '''progesterone''' are important for lobular alveolar growth.

== Lactogenesis and Galactopoesis ==

== Lactogenesis and Galactopoesis ==

== 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]] '''.

* '''[[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]] '''.

== Afferent pathway ==

=== Afferent pathway ===

Mechanical stimulation of the teats activates pressure sensitive receptors in the dermis where the pressure is transformed into nerve impulses that travel via the spinothalamic nerve tract to the brain. These nerves synapse in the PVN and SON. When the cell bodies of the oxytocin-containing neurons are stimulated by these impulses originating in the teat, an action potential moves down the oxytocin-containing neurons from the cell body in the hypothalamus down the axon to the neuron ending in the posterior pituitary. This causes release of oxytocin and neurophysin into the blood.  

Mechanical stimulation of the teats activates pressure sensitive receptors in the dermis where the pressure is transformed into nerve impulses that travel via the spinothalamic nerve tract to the brain. These nerves synapse in the PVN and SON. When the cell bodies of the oxytocin-containing neurons are stimulated by these impulses originating in the teat, an action potential moves down the oxytocin-containing neurons from the cell body in the hypothalamus down the axon to the neuron ending in the posterior pituitary. This causes release of oxytocin and neurophysin into the blood.  

== Efferent Pathway ==

=== Efferent Pathway ===

The efferent pathway begins with the release of oxytocin into the blood. The oxytocin travels to the mammary gland via the blood.  It binds to oxytocin receptors on the myoepithelial cells, causing the myoepithelial cells to contract.  This results in increased intra-lumenal pressure and ejection of milk from the alveolar lumen.  Oxytocin receptors are associated with the myoepithelial cells, not the smooth muscle of the mammary gland.

The efferent pathway begins with the release of oxytocin into the blood. The oxytocin travels to the mammary gland via the blood.  It binds to oxytocin receptors on the myoepithelial cells, causing the myoepithelial cells to contract.  This results in increased intra-lumenal pressure and ejection of milk from the alveolar lumen.  Oxytocin receptors are associated with the myoepithelial cells, not the smooth muscle of the mammary gland.