long term control BP Flashcards
long term control BP involves 3 hormone systems
renin-angiotensin-aldosterone system
antidiuretic factor
atrial natriuretic peptide
where is renin produced
juxtaglomerular cells of kidney
what triggers renin production
- activation sympathetic nerves
- decreased distension of afferent arterioles
- decreased delivery Na/Cl through tubule
what does renin do
converts angiotensin to angiotensin 1
which is then converted to angiotensin 2 by ACE
what does angiotensin II do
- release aldosterone
- increases ADH release
- vasoconstriction
what does aldosterone do
inc Na reabsorption in loop of henle, so reduces diuresis and inc plasma volume
what does ADH do
inc water permeabiliy of collecting duct so reduces diuresis and inc plasma volume
vasoconstriction
increases sense of thirst
where is ADH produces
synthesised in hypothalamus and released from posterior pituitary
what triggers ADH relese
- dec blood volume
- inc osmolarity of interstitial fluid
- circulating angiotensin II
where is ANP produced
produced and released from myocardial cells in atria
what triggers ANP release
increased distension of atrium
what does ANP do
increase excretion of Na+ (natruiresis)
inhibit release of renin
act on medullary CV centres to reduce MAP
