Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Block 9 Week 2 Meg > Duan: Diuretics I > Flashcards

Duan: Diuretics I Flashcards

1
Q

a compact cluster of convoluted capillaries, site of FILTRATION, functioning to remove certain substances from the blood before it flows into the convoluted tubule.

A

glomerulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

List the components of the nephron

A

glomerulus: site of filtration
tubule system: site of reabsorption, secretion, excretion
includes proximal convoluted tubule, Loop of Henle (descending, ascending), distal convoluted tubule, collecting tubule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the favoring force in glomerular filtration? What is the opposing force? How do you determine the net filtration pressure?

A

favoring force: capillary blood pressure
opposing force: blood colloid osmotic pressure
NFP = favoring force - opposing force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

glomeruli in outer cortex & short loops of Henle that extend only short distance into medulla
blood flow through cortex is rapid
majority (70-80%) of nephrons

A

cortical nephron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  • glomeruli in inner part of cortex & long loops of Henle which extend deeply into medulla.
    – blood flow through vasa recta in medulla is slow
    – medullary interstitial fluid is hyperosmotic
A

juxtamedullary nephron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

A two-step process beginning with the active or passive extraction of substances from the tubular fluid into the renal interstitium (the connective tissue that surrounds the nephrons); then these substances are transported from the interstitium into the bloodstream . These transport processes are driven by Starling forces, passive diffusion, and active transport.

A

reabsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does the descending limb of the loop of Henle differ from the ascending limb?

A

descending limb: highly permeable to H20

ascending limb: low permeability to H20 **responsible for 15-50% of reabsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

This portion of the Loop of Henle allows for the passive and active transport of salts such as Na+ and Cl- to move out of the tubules and be reabsorbed. Also, most K+ in the tubules cycles back into the lumen.

A

thick ascending limb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the main function of the Loop of Henle?

A

create a concentration gradient in the medulla of the kidney by means of a countercurrent multiplier system; creates an area of high urea concentration deep in the medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Briefly explain the loop of Henle

A

Descending limb: progressively becomes more concentrated as it loses H20

Vasa recta: removes water leaving the loop

Ascending limb: pumps out Na+, K+, and Cl-, so that the filtrate becomes hypoosmotic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens to Na and Cl in the distal convoluted tubule? What happens to Ca++?

A

Na and Cl- are reabsorbed from the DCT, creating more dilute urine;
Ca++ is also reabsorbed due to PTH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Two cells of the collecting tubule? Which cells are the site of action of aldosterone? Which cells are involved in acid-base homeostasis?

A

principal cells and intercalated cells

  • *aldosterone works on prinicipal cells to reabsorb Na+
  • *intercalated cells participate in acid-base homeostasis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Increases the activity of both apical Na+ channels and the Na+/K+ ATPase in the collecting duct; increases Na+ reabsorption and K+ secretion

A

aldosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

controls the water permeability of principal cells in this segment ;
regulates the insertion of aquaporin-2 (AQP2) into principal cells in the apical membrane

A

ADH (vasopressin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

If you have low ADH or absent ADH, what happens to your urine?

A

large volume of hypotonic and dilute urine, because there is low H20 permeability due to insertion of fewer aquaporins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

If you increase ADH, what happens to your urine?

A

small volume of hypertonic and concentrated urine because there are more aquaporins and increased H20 permeability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How do you calculate the amount of solute excreted in the urine?

A

Amount filtered + amount secreted - total reabsorbed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

This is a carbonic anhydrase inhibitor

A

Acetozolamide

**all end in -amide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How do carbonic anhydrase inhibitors work?

A

inhibit apical and cytosolic carbonic anydrase, thus increase HCO3- excretion
increase Na+, K+, and H20
**results in alkaline urine
causes metabolic acidosis as HCO3- levels drop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

When are carbonic anhydrase inhibitors used as non-diuretics clinically?

A

A FAMILY GAME
Alkalinizing urine for excretion of weak acids
Familial hypokalemic periodic paralysis
Glaucoma (decrease aqueous humor formation)
Altitude (mountain) sickness (decrease CSF and pH)
Metabolic Alkalosis
Epilepsy (seldom used)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the adverse effects of carbonic anhydrase inhibitors?

A 
A PACE
acidosis (metabolic)
potassium depletion
allergic reactions (sulfonamide based)
Ca+ nephrolithiasis
encephalopathy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

In what patient population are carbonic anyhdrase inhibitors contraindicated?

A

can cause hepatic encephalopathy in patients with cirrhosis of liver

**By producing an alkaline urine, CA inhibitors decrease excretion of NH4+ in the urine
This can lead to hyper-ammonemia and hepatic encephalopathy in patients with cirrhosis of the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

These are the osmotic diuretics

A

mannitol
glycerin
isosorbide
urea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How do osmotic diuretics work?

A

freely filtered in the glomerulus
undergo limited reabsorption
quantity of water retained in proportional to the quantity administered

**act primarily in the proximal tubule and to a lesser extend in the ascending loop of Henle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
When are osmotic diuretics used?
AAA ID Acute tubular necrosis (increase urine volume in case of acute GFR decrease) Anuria in hemolysis or rhabdomyolysis (prophylaxis use) Angle-closed glaucoma (reduce intraocular pressure) Increased intracranial pressure (used as the DOC) Dialysis disequilibrium
26
When should osmotic diuretics not be used?
CHF | severe renal disease
27
What are the adverse effects of osmotic diuretics?
if administered too rapidly, can decrease cell volume and impair cell function dehydration hyperkalemia hyponatremia
28
Name 3 adenosine A1 receptor antagonists
caffeine Rolophylline theophylline
29
How do adenosine A1 receptor antagonists work?
interfere with the Na+/H+ exchanger in the proximal convoluted tubule adenosine-mediated enhancement of K+ secretion in the collecting tubule
30
Which 2 loop diuretics are sulfonamide derivatives? Non-sulfonamide derivate?
Furosemide & torsemide Ethacrynic acid
31
How do loop diuretics work? Where do they work in the kidney? What do they block?
Inhibit Na/K/Cl cotransporter in the ascending limb of Henle which decreases hyperosmolarity in the medullary interstitium
32
Clinical use of loop diuretics
Edema related: emergency situations of acute pulmonary edema edema of cardiac, hepatic or renal origin Electrolyte or drug-related: Acute hypercalcemia Hyperkalemia - give with Na+ and water Useful for anion overdose (Br-, Fl-, I-) in addition to saline Torsemide: can decrease blood pressure without diuresis - useful for mild to moderate hypertension
33
Adverse effects of loop diuretics?
Ototoxicity & transient deafness Diabetogenic (furosemide & bumetanide) Compete for binding to serum proteins with drugs, such as warfarin and clofibrate Reduced clearance of Li+ Hyperuricemia due to increased reabsorption of uric acid in proximal tubule caused by decreased vascular volume Hypomagnesemia Severe vascular volume decrease Can lead to hyponatremia if patients increase H2O intake due to hypovolemia-induced thirst Can decrease LDL and triglyceride levels
34
Contraindications to loop diuretic use?
severe Na+ and volume depletion | hypersensitivity to sulfonamides
35
Sulfonamide derivative found while trying to make a better CA inhibitor; produces a diuresis with increase Cl- (not HCO3-); effective in both acidic and alkaline conditions
thiazide diuretics **hydrochlorothiazide
36
How do thiazide diuretics work?
inhibit Na+ and Cl- co-transport in the DISTAL tubule; increase Na+ and Cl- in the urine **weak diuretic since only 5% of filtered Na+ in reabsorbed in the distal tubule
37
What do thiazide diuretics do to the reabsorption of Ca++?
increase overall reabsorption
38
Why are thiazide diuretics preferred?
cause less distortion of the ECF bc they cause a modest diuresis & effect the excretion of several ionic species
39
What are thiazide diuretics used for?
``` edema associated with CHF hypertension Ca++ nephrolithiasis bromide intoxication diabetes insipidus ```
40
Adverse effects of thiazide diuretics?
**Increased cholesterol (5-15% - transient) & LDL Hypokalemia with prolonged therapy Associated with arrhythmias in some settings Hyperglycemia Hypokalemic metabolic alkalosis Hyperuricemia Hyponatremia
41
the volume of fluid filtered from the glomerular capillaries into the Bowman's capsule per unit time
Glomerular filtration rate (GFR) [Urine conc * Urine flow]/plasma concentration
42
Which diuretics do not act on the luminal surface?
aldosterone antagonists
43
How are diuretics that are not filtered at the glomerulus transported into the nephron?
organic acid or base transporters in the proximal tubule
44
What decreases diuretic access to the tubule lumen?
decreased renal blood flow (decreased GFR)
45
Why are diuretics that act proximally weak? Why are diuretics that act distally weak?
even though 70-80% of the filtered load is handles there, their actions are counteracted by more distal reabsorption diuretics that act distally are weak bc only 5-10% of the filtered load is involved
46
Why are loop diuretics the most effective?
1. they inhibit an important transport mechanism (Na/K/Cl transporter) 2. the affected site handles a large fraction of the filtered load (15-50%) 3. more distal mechanisms cannot compensate
47
How do loop and thiazide diuretics differ in how they affect concentration/dilution of urine?
loop diuretics act on the ascending limb of the loop of Henle, where Na+ is reabsorbed but water is trapped - so loop diuretics impair both the concentration and dilution of urine thiazide diuretics act distal to the loop of Henle, so they can influence dilution, but not concentration
48
This loop diuretic can decrease blood pressure without diuresis
Torsemide
49
Thiazide-like diuretic, that has anti-hypertensive actions independent of its diuretic activity; used in cases of renal failure together with loop diuretics
Indapamide
50
This thiazide-like diuretic is efficacious and can be given in combo with a loop diuretic; can be effective in renal insufficiency
Metolazone
51
Why does hypokalemia occur with diuretics?
K+ is exchanged for Na+ in the distal nephron
52
This is an aldosterone agonist that is a K+ sparing diuretic
Spironolactone
53
What does aldosterone do?
essentially it increases Na+ reabsorption and K+ excretion
54
These are two non-aldosterone agonists that are K+ sparing diuretics
Triamterene | Amiloride
55
How do non-aldosterone antagonist, K+ sparing diuretics work?
decrease Na+ reabsorption in the distal nephron - with less Na+ uptake there is a decrease in K+ loss
56
What should you use to treat hepatic cirrhosis and ascites?
thiazide, loop, and K+ sparing diuretics
57
What should you use to treat pulmonary edema?
loop diuretics
58
What should you use to treat cerebral edema?
osmotic diuretics for direct effects
59
What do you use to treat nephrotic syndrome? Acute renal failure? Chronic renal failure?
thiazide diuretics, decrease Na+ intake osmotic or loop diuretics treat aggressively with loop diuretics
60
How to treat hypertension?
decrease salt intake | add thiazides, maybe a K+ sparing or loop diuretic
61
How to treat nephrolithiasis?
treat with thiazides to increase Ca++ reabsorption | decrease salt intake
62
How to treat hypercalcemia?
treat with loop diuretics to increase calcium excretion | + normal saline to prevent contraction of extracellular space, +/- K+ sparing diuretics as needed
63
How to treat nephrogenic diabetes insipidus?
treat with thiazide or loop diuretics to reduce plasma volume and contract the extracellular space
64
What is diabetes insipidus?
increased urine output due to decreased ADH
65
What are the two types of diabetes insipidus? Which type will respond to desmopressin, an ADH analog?
central: decreased ADH due to injury, tumor or infection **will improve with desmopressin nephrogenic: decreased ADH responsiveness **won't respond to treatment with desmopressin
66
What is SIADH?
syndrome of inappropriate secretion of ADH --> too much ADH --> too much H20 reabsorption

Block 9 Week 2 Meg (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions