Nephron - Handling of Solutes

Where is 67% of Na+ reabsorbed under normal conditions in the nephron?

Proximal Convoluted Tubule

Where is 67% of K+ reabsorbed under normal conditions in the nephron?

Proximal Convoluted Tubule

Where is 70% of Phosphate reabsorbed under normal conditions in the nephron?

Proximal Tubule

Where is 15% of Phosphate reabsorbed in the nephron under normal conditions?

Proximal Straight Tubule

How much phosphate is excreted in the urine?

15%

Why is 15% of phosphate excreted in the urine?

Buffer for H+ (becomes H2PO4-)

In early proximal tubule Na+ and other ions are reabsorbed with water.. what is this called?

Isosmotic reabsorption

How much Mg is absorbing in the early proximal convoluted tubule?

30%

How much Glucose is remaining in the middle portion of the proximal CT? (under normal conditions)

0%

How much amino acid is left in the middle portion of the proximal convoluted tubule? (under normal conditions)

0%

How much bicarb is filtered by the middle portion of the convoluted tubule?

85%

In the late proximal tubule Cl- is exchanged on the luminal side by what transporter?

Cl- / Formate exchanger

Once Cl- is in the late PCT cell, it moves into the blood how?

Paracellular transport

As Cl- is leaving, it creates a (+) charge in the cell, what ion is thus driven out with Cl- ?

Na+

Is the thin descending limb of the loop of henle water permeable?

yes

In the PTC, parathyroid hormone acts indirectly on Na/phosphate co-transporters. Does PTH increase or decrease phosphate reabsorption?

decrease

True or false? Parathyroid hormone increases increases excretion of phosphate?

true

Fibroblast Growth Factor 7, released by osteocytes, acts on Na/Phosphate co-transporter. Does it increase or decrease phosphate excretion?

increase

Fanconi syndrome primarily affects the reabsorption of glucose, AA, phosphate, and HCO3-. What are some of the effects?

phosphaturia, glucosuria, aminoaciduria, hypovolemia, acidosis

Glomerular tubular balance