Part 22: Renal Function & BP Modulation Flashcards
what is the normal blood pressure?
120/80 mmHg
what is the target BP in patients with CV risk, diabtes, or kidney disease?
<130/80 mmHg
what is considered a dangerous BP (hypertensive crisis)?
> 180/120 mmHg
what are 3 strategies to reduce BP?
- reduce blood volume
- reduce vascular resistance
- reduce force of heart contraction
why is high BP dangerous?
puts stress on BV and organs
what are the main functions of the kidneys? (4)
- production of regulatory enzymes & hormones including renin
- filtering out waste products, metbolites & chemicals from the blood
- regulate water and electrolyte
- regulate BP
_____ of the kidney are the individual filtering units of the kidneys
nephrons
what is the function of the nephrons?
filtering, used to remove substances from the blood and excrete them in urine
t/f there are multiple sites of ion & solute reabsorption along the nephron
t
the thick ascending limb of the nephron expresses ion transporters that allow the reabsorption of ____, ____, and ___ from the urinary compartment
Na; K; Cl
the flow of K can go back into the urinary compartment of the acsending loop and creates a _____ (positive/negative) potential that increases the reabsorption of _____ions such as ___ and ____ back into the blood
positive; Mg and Ca
where do loop diuretics like furosemide act?
in the ascending limb
what is the MOA of loop diuretics like furosemide?
blocks the NKCC2 to reduce the transport of Na, K, and CL in the thick ascending limb and Mg and Ca reabsorption are also decreased, meaning more will be excreted in urine (along with water)
can water move in/out of the thick ascending limb of the nephron?
no
t/f loop diuretics like furosemide are effective in promoting the excretion of large volumes of fluid
t
furosemide is typically indicated for the management of edema associaed with ____, but can also be used for ____ when patients requires a diuretic effect
congestive heart failure; hypertension
which ion transporters are found in teh distal convoluted tubule?
Na/Cl co-transporter (NCC)
in the distal convoluted tuble, NCC facilitate the reabsorption of ions into the ___
blood
which hormone acts on the distal convoluted tubule to increase reabsorption of Ca?
PTH
what type of diuretics block the NCC in the distal convoluted tubule?
thiazide-like diuretics, like hydrochlorothiazide
what is the MOA of thiazide-like diuretics?
block the NCC, reducing the reabsorption of Na in the distal convoluted tubule
why are other thiazide-like diuretics typically given over hydrochlorothiazide?
they typically have a longer half life than HCTZ
what is the regular dosing of HCTZ?
BID
t/f bc the reabsorption of multiple ions are linked together by co-transport mechanisms, impairing the reabsorption of Na can impact other ions
t
the actions of loop diuretics and thiazide diuretics are most likely to cause an overall loss of ____ ions, resulting in hypo-___
K , kalemia
what are some of the symptoms of hypokalemia?
- increased blood pH (alkylosis)
- muscle weakness
- cardiac arrhythmias
why might hypokalemia cause muscle weakness and cardiac arrhythmias?
due to the importance of K ions in action potential generation
t/f patients on loop and thiazide duiuretics should have regular blood monitoring for K levels
t
t/f it would be reasonable to recommned a patient taking a thiazide or loop diuretic to eat bananas
t
what is the benefit of K sparing diuretics?
they do not cause a net excretion of K in urine and promote reabsorption of K in the collecting tubule
K sparing diuretics act at what part of the nephron?
collecting tubule
____ is the final segment of the nephron where Na reabsorption can occur before excretion in urine
collecting tubule
in the collecting duct, Na follows its ____ and ____ gradient from the nephron lumen into the ___-cell through Na channels
concentration and electrical; principle
how is the transport of Na ions in the collecting tubule different than in other sections of the nephron?
only Na is going through the channels, there is no co-transport with Cl