Renal handling of solutes and renal stones

Question 1

What are kidney stones?

Answer 1

Precipitated salts which grow into calci

Question 2

Urolithiasis

Answer 2

In urinary tract

Question 3

Nephrolithiasis

Answer 3

In kidney

Question 4

Nucleation

Answer 4

Ions come together in CD

Question 5

Aggregation

Answer 5

Crystals aggregate in renal pelvis

Question 6

Renal colic

Answer 6

pain associated with kidney stone - lower back pain, nausea and vomiting, intermittent pain

Question 7

5 types of kidney stones

Answer 7

• Calcium-containg stones (calcium oxalate (alkaline/acidic) and calcium phosphate(alkaline))
• Magnesium ammonium phosphate - alkaline conditions
• Uric acid stones - acidic conditions
• Cystone stones - acidic conditions
• Xanthine stones

Question 8

Risk factors for calcium stones

Answer 8

• Calcium supplements
• Calcium antacids
• Foods high in oxalates - spinach, pecans, peanuts

Question 9

Risk factors for magnesium ammonium phosphate stones

Answer 9

• Women, UTIs

- Alkaline environment favours crystal formation

Question 10

Risk factors for urate stones

Answer 10

• High uric levels in blood plasma (hyperuricemia)
• Probenecid - increased urate excretion
• Not visible on x-rays

Question 11

Treatment for kidney stones

Answer 11

• Tamsulosin is a alpha1a antagonist to dilate ureter
• Keterolac is NSAID
• Hydromorphone or morphine is opioid for pain
• Zofran for vomiting

Question 12

Shock wave lithotripsy

Answer 12

• High frequency ultrasound targets stone

- Breaks it up

Question 13

Uteroscopy

Answer 13

• Medium stones
• General anaesthesia
• Ureteroscope to visualise stone

Question 14

Percutaneous nephrolithotomy

Answer 14

• Hole into back at kidney level
• Camera inserted
• Visualise stone
• Pulverised using ultrasound

Question 15

prevention of kidney stones

Answer 15

• Lots of fluids
• Limit oxalates and calcium supplements
• Decrease nondairy animal protein
• Decrease sodium
• Decrease fructose and sucrose
• Increase potassium
• Increase phytates
• Apple cider vinegar

Question 16

How do thiazide diuretics prevent kidney stones?

Answer 16

stop sodium-calcium symporter in DCT so decreases intracellular sodium and increase sodium movement into cell by anti-porter so more calcium reabsorbed

Question 17

What do SGLT2 cotransporters move?

Answer 17

Na+ anf glucose

Question 18

When is acetazolamide used?

Answer 18

Altitude sickness

Question 19

What is empahglifloxin

Answer 19

Reversibly inhibits sodium-glucose co- transporter 2 (SGLT2) in the renal proximal convoluted tubule to reduce glucose in diabetics

Question 20

Which substances does empaglifloxin move?

Answer 20

Cl-, K+, water, amino acids out of lumen and H+ in

Question 21

Which substances does acetazolamide move?

Answer 21

HCO3-

Question 22

What is the purpose of the countercurrent principle?

Answer 22

Maintains hypertonic interstitial

Question 23

What happens in ascending LOh

Answer 23

Reabsorbs solutes but no water - creates hypertonic medulla

Question 24

Which substances does the NKCC2 cotransporter and loop diuretics move and where

Answer 24

Na+, Cl-, K+ out of lumen

Question 25

Which molecules determine the paracellular voltage and what is this

Answer 25

Ca2+ and Mg2+ moving out - voltage is 8mV

Question 26

Why is the inside of the cell positive?

Answer 26

Backleak of potassium through cells

Question 27

PTh effect on calcium

Answer 27

Stops it being excreted

Question 28

What happens to glucose concentration in PCT?

Answer 28

Falls to 0

Question 29

What happens if we block SGLT2

Answer 29

Blocking SGLT2 so urinate sugar in diabetics - line would be less steep Concentration would increase in descending limb and then stay constant in rest of LOH In DCT concentration would steeply increase

Question 30

Characteristics of calcium oxalate crystals

Answer 30

radio-opaque Small and numerous Can form in any urine

Question 31

Characteristics of calcium phosphate crystals

Answer 31

Radio-opaque Small and numerous Form in alkaline conditions - hyperparathyroidism

Question 32

Characteristics of magnesium crystals

Answer 32

radio-opaque alkaline urine Staghorn

Question 33

Characteristics of uric acid crystals

Answer 33

High purine diets, malignancies and metabolic defects Radio-lucent Acidic urine Small, numerous, stag horn

Question 34

Characteristics of cystine and xanthine crystals

Answer 34

Metabolic defects Soft and waxy Faint on x-ray especially in children

Question 35

Function of ANP

Answer 35

ANP counteracts aldosterone ANP released in response to increased intravascular volume

Question 36

What are type A and B cells

Answer 36

Type A and B are both intercalated cells Type A cells like to get rid of Hydrogen ions into tubular lumen and hold onto bicarb - correct acidosis pCO2 increases due to hyperventilating Type B cells hang onto hydrogen and get rid of bicarb

Question 37

What is spironolactone

Answer 37

Aldosterone antagonist - sodium/chloride potasisum exchange

Question 38

Impact of aldosterone and ANP on tubule

Answer 38

Move sodium and chloride out and potassium in

Question 39

Impact of aldosterone on tubule

Answer 39

Moves HCO3- and K+ out and H+ in