Renal 8 Flashcards
whats the opposing pathway to renin angiotensin system
the ANP pathway
what region of the brain is responsible for thirst and salt
hypothalamus
2 main stimuli for ingesting salt
aldosterone
angiotensin II
whats an avoidance behaviour
avoid heat to avoid fluid loss
the cv system responds to changes in ________________ and _________
blood volume and pressure
the renal system responds to changes in ________________ and ___________
blood volume
osmolarity
what situation can cause hypokalemia or hyponatremia
no change in volume but a decrease in osmolarity
(sweating but only water replaced)
what happens during dehydration
decreased volume
increased osmolarity
does dehydration result in low BP
yes
what are the 3 factors that aim to restore dehydration
conserving fluid
trigger cardiovascular reflexes to increase blood pressure
stimulate thirst
what are the 4 compensatory mechanisms to overcome symptoms of dehydration
- cardiovascular mechanisms
- renin angiotensin system
- renal mechanisms
- hypothalamic mechanisms
whats the first thing that happens when you are dehydrated
carotid and aortic baroreceptors signal CVCC to increase sympathetic activity and blood flow
what decreases GFR to maintain body fluid
a drop in blood pressure
what are the 5 steps to fixing dehydration
- baroreceptors signal CVCC to increase sympathetic activity and vasoconstricts afferent arterioles
- That causes a decrease in GFR
- paracrine feedback from macula densa cells in the nephron cause granular cells to release renin
- granular releases renin
- ANGII, and the low blood pressure stimulates vasopressin release and the thirst centres of the hypothalamus
why isn’t aldosterone release during dehydration
the high osmolarity inhibits it as the body doesn’t need more solute
whats the normal pH of the body
7.4
are humans neutral
no we are slightly alkaline (7.4)
does a single pH unit change represent a large hydrogen change
yes
what can a change in pH do to protein
denature and change function
whats a low pH called
Acidosis
whats a high pH called
alkalosis
what can acidosis do
CNS depression
confusion
coma
what can alkalosis do
hyperexcitability in neurons and muscles
are we exposed to more acid or base
acid
