Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.

Remove Ads
Don't know
remaining cards
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards

Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Renal 23 Kidney & Ca

Komar: The kidney and Ca homeostasis

Serum Ca stores Ionized Ca (~50%) -Biologically active Protein-bound (~40%) Complexed to anions (~10%)
Ca homeostasis is primarily regulated by Parathyroid Hormone (PTH) -mobilize form bone Vitamin D -absorb from instetines
What couples with free Ca? Phosphate
How does PTH effect phosphate levels? Acts in the kidney to ↑phosphate excretion and ↓ reabsorption
What primary signals does PTH respond to? Absolute [Ca] Rate of fall of [Ca]
Effects of PTH in the kidney + Ca reabsorption - Phosphate reabsorption + primary hydolysis (responsible for activating Vit D.
Majority of phosphate is reabsorbed... In the proximal tubule
What mechanism is responsible for the increase in phosphate excretion in the presence of PTH? PTH inhibits the phosphate transporter from working and marks it be degraded by the lysosomes
Where along the nephron is what percent of Ca reabsorbed. Proximal tubule ~60% Thick ascending limb ~25% Distal convoluted tubule ~5% Collecting duct ~10%
Effect of PTH on Vitamin D and Ca uptake in the distal tubule PTH increase activity of an apical Ca channel Inside the cell Ca binds to Vit D which transports it cross cell Ca pumped out by Na/Ca exchange and Ca ATPase
How does Vitamin D affect PTH? Vitamin D feeds back to the parathyroid and decreases PTH secretion
Vitamin D and intestinal absorption of Ca. Vit D increases the synthesis of Ca binding proteins which grab Ca form the brush boarder side
How does elevated PTH cause hypercalciuria? PTH effect on bone resorption causes increased fluid levels of Ca These levels are higher than what hte kidney can absorb
Elevated PTH can cause _____ (phosphate) Hyperphosphaturia -↓resorption, ↑excretion
What would you expect to see with Ca in acidosis? ↓ renal Ca absorption ↓ protein binding to Ca thus ↑ionized[Ca] Promotes degradation of bone
What would you expect to see with Ca in alkalosis ↑ renal reabsorption of Ca ↑ protein binding to Ca so ↓ionized[Ca]
True/False Loop diuretics may decrease Ca excretion False It increases Ca excretion
Created by: bcriss