Diuretics Flashcards
True or false?
A “natriuretic” causes an increase in renal sodium excretion
How do Natriuretic peptides affect the kidney, heart, nervous and vascular system?
True
promotes the excretion of sodium (Na+) in the urine. They are secreted by the atria and ventricles.
Kidney: inhibits RAAS and renal SNA , Increases GFR. This increases Na and water excretion
Heart: reduces cardiac load, inhibits hypertrophy and fibrosis.
Vascular system: vasodilation, hypotensive and angiogenic effects
Nervous system: inhibits SNS, lowers vagal afferents activation threshold.
True or false
An “aquaretic” increases excretion of solute-free water
True
True or false
Interstitial fluid is found inside cells
False
Interstitial fluid is the fluid found outside the cells.
The fluid inside cells is called intracellular fluid.
Vessel elasticity is reduced because
Increase in age
Reduced nitric oxide
Increased sodium ions
Elevated chloride ions
Increased Na ions ?
True or false
The afferent renal arteriole is larger in diameter than the efferent renal arteriole
True
How is Fluid compartmentalized and body water distributed ?
How does Fluid move between compartments?
Between Intracellular fluid ICF 66%, Interstitial fluid IF and Plasma
Via
1. filtration- fluid exits capillary (arterial end net filtration pressure +10 mm Hg
2. Reabsorption- fluid reenters capillary (venous end net filtration pressure - 7 mm Hg
3. and no net movement
T/F?
Anti diuretic hormone causes increased elimination of water
Reabsorption of fluid occurs in the mid and venous end of the capillary
F
F
ADH actually promotes water retention.
Fluid reabsorption primarily occurs at the venous end
T/F?
Elevated levels of ANP are found during hypervolemic states
True
Atrial Natriuretic Peptide (ANP) is released by the atria of the heart in response to increased blood volume (hypervolemia) and atrial stretch.
Explain Neurohormonal volume regulation (RAAS)
Kidneys release renin when blood pressure is low.
It converts angiotensinogen in the liver to angiotensin I
ACE (Angiotensin-Converting Enzyme) from the lungs converts angiotensin I to angiotensin II
Angiotensin II causes
1) arteries to constrict, increasing bp
2) signals the pituitary gland to secrete ADH, reabsorbing water
3) Signals the adrenal glands to release Aldosterone, reabsorbs Na and Cl
excretes K and retains water
4) increases sympathetics activity by activating norepinephrine (NE) and epinephrine (Epi), vasoconstriction
When Na+ reabsorption is altered it can result in
edema (fluid buildup in tissues)
Peripheral edema is fluid buildup in the extremities (legs, feet, hands)
What are diuretics used for?
How do they work?
Used when there is too much water (extracellular fluid) in the body.
e.g. Edematous states( too much fluid) : CHF, hepatic cirrhosis, nephrotic syndrome.
Non-edematous states (other): Hypertension, diabetes insipidus, nephrolithiasis, hypercalcemia, glaucoma.
1) increases urine production by altering Na and H2O.
Diuretics: Points to know
1) Bind to protein, so they aren’t really filtered but secreted across the proximal tubule by pumps.
2) drugs eg NSAIDS compete for pumps thus reducing diuretics efficacy.
3) must enter luminal side of kidney tubule
4) renal failure or reduced renal blood flow can reduce efficacy.
Loop diuretics ..T/F?
Can be used to treat hypercalcemia
Used for pulmonary edema
Can be used to treat hypokalemia
T
T
F
