Changes

====Action on the Renal Tubules====

====Action on the Renal Tubules====

ADH is released in response to reduction in plasma volume, a decrease in blood pressure (detected by baroreceptors in the left atrium, pulmonary vessels, aortic arch and carotid sinus), high levels of angiotensin 2 (part of the [[Renin Angiotensin Aldosterone System| RAAS]]), increased sympathetic activation or an increase in the osmolarity of the extracellular fluid (ECF)(detected by osmoreceptors within the [[Hypothalamus - Anatomy & Physiology|hypothalamus]]). If the osmolarity is high or the volume is low, ADH will be released. This acts on the renal tubules, decreasing water loss into the urine by the following mechanisms:

ADH is released in response to reduction in plasma volume, a decrease in blood pressure (detected by baroreceptors in the left atrium, pulmonary vessels, aortic arch and carotid sinus), high levels of angiotensin 2 (part of the [[Renin Angiotensin Aldosterone System| RAAS]]), increased sympathetic activation or an increase in the osmolarity of the extracellular fluid (ECF)(detected by osmoreceptors within the [[Hypothalamus - Anatomy & Physiology|hypothalamus]]). If the osmolarity is high or the volume is low, ADH will be released. This acts on the renal tubules, decreasing water loss into the urine by the following mechanisms:

* Acts on V2 receptors on the peritubular surface of the collecting ducts in the kidney.  

It acts on V2 receptors on the peritubular surface of the collecting ducts in the kidney. The permeability to water in the [[Reabsorption and Secretion Along the Distal Tubule and Collecting Duct - Anatomy & Physiology#Distal Tubule|distal tubule]] and [[Reabsorption and Secretion Along the Distal Tubule and Collecting Duct - Anatomy & Physiology|collecting duct]] is increased via insertion of [[Aquaporins of the Kidney and Water Homeostasis - Anatomy & Physiology| aquaporins]] into the apical membrane of principal cells (aquaporins are always present in the basolateral membranes). More water therefore, moves out of the tubule and into the intracellular space. Urine volume decreases and urine concentration increases. It is also released in response to '''cholecystokinin''' from the small intestine.

* Permeability to water in the [[Reabsorption and Secretion Along the Distal Tubule and Collecting Duct - Anatomy & Physiology#Distal Tubule|Distal Tubule]] and [[Reabsorption and Secretion Along the Distal Tubule and Collecting Duct - Anatomy & Physiology|Collecting Duct]] is increased via insertion of [[Aquaporins of the Kidney and Water Homeostasis - Anatomy & Physiology| aquaporins]] into the apical membrane of principal cells (aquaporins are always present in the basolateral membranes).

* More water moves out of the tubule and into the intracellular space.

* Urine volume decreases

* Urine concentration increases

 

 

* It is also released in response to Cholecystokinin from the small intestine

====Action on the Blood Vessels====

====Action on the Blood Vessels====