Long Term Control Of Blood Pressure Flashcards
What does the long term control of blood pressure revolve around?
The control of plasma volume by the kidney through 3 hormonal systems;
Renin angiotensin aldosterone system
Anti diuretic factor ADH
Atrial nautriuretic peptide
The regulation of plasma volume by the kidneys is known as what system?
The renal counter current system
What receptors detect plasma volume in the kidneys?
Atrial volume receptors which are low pressure baroreceptors
When the collecting duct is impermeable what does this result in?
Little water absorption , lots of urine and a reduction in plasma volune
= large volume of hypo osmotic urine
Where is renin produced from?
The juxtoglomerular of kidney
What is renin production stimulated by?
Activated by a decrease in MAP through;
Activation sympathetic nerves to juxtoglomerular apparatus
Decreased distension of afferent arterioles
Decreased delivery of sodium and chlorine through tubule
What is the role of renin?
Renin converts angiotensin to angiotensin II
What is the action of angiotensin II?
Stimulates release of aldosterone from adrenal cortex
Increases release of ADH from pituitary
Vasoconstrictor
Where is anti diuretic hormone synthesised and produced?
The hypothalamus and produced in the pituitary
What is ADH release triggered by?
Decrease in MAP which is signalled by;
Decrease in blood volume
Inxrease in osmolarity of interstitial fluid
Circulating angiotensin II
What is the action of ADH?
Increases permeability of the collecting duct to water and therefore reduces diuresis and increases plasma volume
Causes vasoconstrition and therefore increases MAP
Where is atrial natriuretic peptide produced and released from?
ANP is produced and released from the myocardial cells of the atria
What is ANP release triggered by?
ANP is stimulated by a rise in MAP which is detected by;
Increased distension of atria
What is the action of ANP?
Increases excretion of sodium
Exhibits the release of renin
Acts on medullary cardiovascular centers to reduce MAP
what is produced from the juxtoglomerular apparatus of the kidney?
renin
