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ADH RAA Aldosterone
how blood pressure is maintained.
Hint | Answer |
---|---|
blood pressure control | blood pressure is controlled by vasoconstriction/vasodilation/baroreceptors and the RAA aldosterone negitive feedback loop |
baroreceptors | found in the arch of the aorta and the cartoid bodies |
a drop in blood pressure | is detected by the baroreceptors |
the baroreceptors | send a message to the cardiovascular centre in the brain (MEDULLA OBLONGATA) |
these messages | cause an increase in sympathetic activity causing the heart to speed up |
heart speeds up | vasoconstriction occurs and blood pressure will be raised |
RAA &aldosterone (adh) | RENIN ANGIOTENTIN ALDOSTERONE MECHANISM |
decreased BP | detected by the aterial pressure in the kidney |
baroreceptors in the JGA juxtaglomerula apparatus in the kidney | secrete renin into the blood |
renin converts | angiotensinogen to angiotentsin 1 |
angiotenstin 1 turns to | angiotensin 2 |
this causes 2 things to happen | vasoconstriction in the ateries of the kidney to maintain normal pressure in the kidney |
and secondly | angiotensin 2 stimulates the adrenal cortex to increase aldosterone secretion by the adrenal gland |
= more sodium and therfore more water are | reabsorbed into the blood |
causing | an increase in blood volume |
therefore | blood pressure will increase |
ADH= | anti duiretic hormone |
reduced blood volume | detected by osmoreceptors in the posterior pituritary gland |
posterior pituritary | releases an increased ammount of ADH |
causing | an increased permiability in the distal convoluted tubule in the kidney therefore blood volume will increase therefore blood pressure will increase. |