Sketchy Path: Calcium Oxalate Stones and Calcium Phosphate Stones Flashcards
The most common cause of calcium kidney stones is _________________.
idiopathic hypercalciuria with normocalcemia (like the guy with the normal amount of milk and the cow dripping too much milk into the ravine)
It’s thought that normocalcemic hypercalciuria might result from _____________.
too much absorption of calcemia from the gut (like the gut design on the cow)
Though most people with kidney stones are normocalcemic, _____________ can cause kidney stones.
hypercalcemia –such as from hyperparathyroidism –
Think of the other farmer lifting two buckets of milk and spilling lots of it down into the ravine.
Metabolic ____________ can cause hypercalcemia.
acidosis (like the guy dissolving bones with acid)
_______________ binds calcium and prevents kidney stones by shuttling calcium out in a non-precipitable form.
Citrate (like the citrate crate that has safely bottled up the milk)
In addition to direct dissolution of bone, metabolic acidosis also causes kidney stones by _______________.
shuttling citrate to serve as a buffer molecule; with less citrate in the nephron, calcium can precipitate more easily
(Think of the miners storing their stones in citrate crates after their acid operation.)
Diets high in ____________ can cause kidney stones.
meat (like the acid miner eating the chicken leg)
The more protein degraded leads to more acid generation… you know the rest.
Why does vitamin C deficiency cause kidney stones?
Citrate is a derivative of vitamin C (which is why the citrate crate has an orange on it)
Why does a diet high in sodium cause kidney stones?
More sodium absorption means more calcium excretion in the nephron (via the DCT), so more sodium equals more calciuria (like the peanuts falling into the ravine with more milk).
True or false: eating less calcium makes you have fewer kidney stones.
False. Like in Crohn’s disease, less calcium in the gut means more oxalate absorption which increases the likelihood of calcium oxalate formation.
(Think of the guy spilling his milk –decreased calcium –as the oxen charge into the ravine.)
Crohn’s is represented by ____________.
the cobblestones that skip
Although almost all calcium stones are calcium oxalate, calcium phosphate is more common in ____________.
children (like the kids mining phosphate)
Calcium phosphate stones are more common in what body state?
Alkaline urine, such as that found in type 1 renal tubular acidosis –the failure to excrete H+ by the alpha-intercalated cells
(Think of the 1-shaped beaker near the child-labor mine.)
What shape do calcium oxalate and calcium phosphate stones have?
- Calcium oxalate: x-shaped, kind of like an envelope (like the envelopes trailing behind the cart)
- Calcium phosphate: elongated wedges (like the wedge-shaped carts used by the kids)
