Komar: The kidney and Ca homeostasis
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
|
|
||||
|---|---|---|---|---|---|
| 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
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
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
Normal Size Small Size show me how
Created by:
bcriss
Popular Medical sets