Nephron Functions

Question 1

Proximal Tubule

• Excreted
• Reabsorbed

Answer 1

Reabs:

1. glucose, aa, protein

Question 2

THICK descending

• Excreted
• Reabsorbed

Answer 2

Reabs:
Excr:

Question 3

thin descending LoH

• Excreted
• Reabsorbed

Answer 3

Reabs:

1. H2O

Question 4

thin ascending LoH

• Excreted
• Reabsorbed

Answer 4

H2O impermeability dilutes fluid
Reabs:
1. Na

Excr:
2. Urea

Question 5

THICK ascending limb

• Excreted
• Reabsorbed

Answer 5

**H2O impermeability** = dilutes fluid
Re-abs:  (Na/K/2Cl-) 
1. Na
2. Cl
3. K+
4. Mg++
5. Ca++
6. HCO3
7. H2O 
8. glucose, aa, protein

Excrete-
1. H+ ions

(X) Furosemide (loop diuretic)–/Na/K/2Cl

Question 6

Early Distal Tubule

• Excreted
• Reabsorbed

Answer 6

**H2O impermeability**
Reabs: 
1. Na (Aldosterone dep) 
2. Cl
3. K
4. Ca++
5. Mg++
6. HCO3

Excr:
1. K
2. Urate
3. NH3
4. H+ ions 
(X) Thiazide diuretic --/NaCl cotransporter

Question 7

Late Distal Tubule
-Excreted
-Reabsorbed
(2 Cell types)

Answer 7

Principal Cell (light)
water reabs + ENaC
       Reabs: 
            1. H2O (ADH--> aquaporin)
             2. Na (Aldosterone) 
       Excr: 
             1. K+
Intercalated Cell (dark)- acid/base balance 
      Reabs:  HCO3
      Excr: H+
(X) K+ sparing diuretics/Na+ channel blockers--/ENaC
(X) Aldosterone antagonists--/ Na+ abs w K+ excr

Question 8

Collecting Duct

• Excreted
• Reabsorbed

Answer 8

Reabs: 
1. H2O (ADH--> aquaporin)
2. urea
3. NaCl
4. HCO3-
Excr: 
1.  H+