Changes

==Control of Blood Pressure==

==Control of Blood Pressure==

* If more sodium is excreted less water is reabsorbed therefore the ECF volume decreases and blood pressure decreases.

* If more sodium is excreted less water is reabsorbed therefore the ECF volume decreases and blood pressure decreases.

* The actual mechanism is not clear but it is thought to involve a direct effect of the pressure on the renal interstitium.

* The actual mechanism is not clear but it is thought to involve a direct effect of the pressure on the renal interstitium.

=====[[Important Hormonal Regulators of the Kidney - Anatomy & Physiology#The Renin Angiotensin Aldosterone System (RAAS)| Renin-Angiotensin-Aldosterone System]]=====

=====[[Renin Angiotensin Aldosterone System| Renin-Angiotensin-Aldosterone System]]=====

* Specialized cells in the distal tubule called the macula densa sense the concentration of sodium and chloride.

* Specialized cells in the distal tubule called the macula densa sense the concentration of sodium and chloride.

* If blood pressure falls there is a reduction in concentration of sodium and chloride in the distal tubule which is sensed by the macula densa.

* If blood pressure falls there is a reduction in concentration of sodium and chloride in the distal tubule which is sensed by the macula densa.

* The drop in blood pressure is also detected by baroreceptors in the aortic arch, carotid sinus and the afferent renal arteriole which stimulates renin release by the juxtaglomerular apparatus.

* The drop in blood pressure is also detected by baroreceptors in the aortic arch, carotid sinus and the afferent renal arteriole which stimulates renin release by the juxtaglomerular apparatus.

* Renin cleaves angiotensinogen into angiotensin 1 which in turn is cleaved by [[Angiotensin Converting Enzyme(ACE) - Renal Anatomy & Physiology|'''Angiotensin Converting Enzyme''' (ACE)]]  into angiotensin 2.

* Renin cleaves angiotensinogen into angiotensin 1 which in turn is cleaved by [[Angiotensin Converting Enzyme(ACE) - Renal Anatomy & Physiology|'''Angiotensin Converting Enzyme''' (ACE)]]  into angiotensin 2.

* Angiotensin 2 is a potent vasoconstrictor and also stimulates the adrenal cortex to release [[Important Hormonal Regulators of the Kidney - Anatomy & Physiology#Aldosterone|aldosterone]].

* Angiotensin 2 is a potent vasoconstrictor and also stimulates the adrenal cortex to release [[Aldosterone|aldosterone]].

* [[Important Hormonal Regulators of the Kidney - Anatomy & Physiology#Aldosterone|Aldosterone]] acts on the distal tubules and collecting ducts in the kidney causing retention of sodium and water.

* [[Aldosterone|Aldosterone]] acts on the distal tubules and collecting ducts in the kidney causing retention of sodium and water.

* Blood pressure increases.

* Blood pressure increases.