Renal Basic Functions Flashcards
How do the kidneys participate in Acid-Base balance
Bicard reabsorption and riding the body of acid
What 3 hormones do the kidneys produce?
Renin
Erythropoietin
Vit D3
How much blood do the kidneys receive?
About 25% per minute (a liter per min)
RBF is maintained between
50-180 mmHg
Is there a direct relationship between RBF and GFR?
YES
When does filtration cease
MAP below 50
Can the kidneys override the SNS?
YES
What happens when the kidneys release renin?
Increased aldosterone secretion to increase blood pressure
Aldosterone causes reabsorption of ______&____
secretion of _________
Na+ and H2O
K+
Aldosterone works were in the kidneys?
DCT and CD
What is the strongest trigger of aldosterone release?
HYPERkalemia
What is ADH’s (antidiuretic hormone) affect on distal tubular area?
Increases its permeability to water
What does the RAAS system do
Converts Angiotensin II to cause vasoconstriction
Renin/Angiotensin causes reabsorption of ____&____
secretion of ______
causes release of _____&_____
NaCl and H2O
K+
aldosterone & ADH
Which medication inhibit RAAS?
ACE inhibitors, ARBs, Beta-Blockers, Aldosterone Antagonists, Renin Antagonists
ANF (atrial natriuretic factor) effects on the kidneys
increases urine flow and promotes Na+ excretion, vasodilates, and may increase RBF & GFR
When is ANF released?
When there is an atrial stretch
Prostaglandin E2 causes
Vasodilation
Thromboxane A2 causes
Vasoconstriction
What percentage of bicarb is reabsorbed?
99%
The kidneys try to maintain a pH of
> 4.5
What do the kidneys do to H+ (hydrogen ions)
excrete them
H+ combines with bicarbonate to form__________
carbonic acid
What breaks down carbonic acid into water and CO
carbonic anhydrase
The body takes up bicarb in exchange for
Cl-
Acid base balance primarily happens where?
Proximal Tubule
What is the order of urine filtrate formation?
Filtration
Reabsorption
Secretion
Excretion
GFR per day
180 L/day (178 reabsorbed)
How do we estimate GFR
filtration markers
How is GFR increased
Increasing RBF
Afferent VASODILATION
Efferent VASOCONSTRICTION
How is GRF decreased
Decreased RBF
Afferent CONSTRICTION
Efferent DILATION
NSAIDs ________afferent arterioles, ________GFR and flow (_______ ________)
constrict; decrease; kidney damage
NSAIDs inhibit ________ _________, causing vaso_________
prostaglandin production; constriction
ACEI/ARBs _________ efferent arterioles and provide kidney ________
dilate; protection
Reabsorption & Secretion can happen by
active or passive mechanisms
Where is water permeable?
PCT & beginning of Loop of Henle
Where is most of the Na+ reabsorbed?
PCT
Where do thiazide diuretics work?
DCT
In the absence of ADH, the final urine will be
dilute
In the presence of ADH, the final urine concentration will be
concentrated
