Kidney Pathophysiology

Question 1

Basic functional unit of the kidney
*900K to 1 million in each kidney

Answer 1

Nephron

Question 2

Filtering unit
Made from network of capillaries surrounded by narrow wall of epithelial cells
Forms ~125 mL/min of filtrate w/in __
__ with basement membrane encompasses __ and form __ together

Answer 2

Glomerulus/Bowman’s Capsule/Renal Corpuscle

Question 3

Direct continuation of epithelium of Bowman’s capsule
Controls reabsorption of filtered glucose, AA, Na, HCO3, K, Cl, Ca, P, water, and other solutes
Manages secretion of renally excreted drug metabolites
Produces ammonium

Answer 3

Proximal convoluted tubule

Question 4

Concentrates urine, which may be diluted later in excretory system
Unable to permeate water–but can pump out sodium
Influences movement of water in or out of water-permeable collecting duct

Answer 4

Loop of Henle

Question 5

Three parts (thick ascending limb of Loop of Henle, macula densa, distal convoluted tubule)
Ability to actively transport NaCl in thick ascending limb
Concentrates urine by absorbing ~99% of water that is filtered by the kidneys back into the body
This ascending limb functions are governed by vasopressin, PTH, calcitonin

Answer 5

Distal tubule

Question 6

Principal and intercalated cells
Controls reabsorption of NaCl and secretion of K via principal cells
Regulates acid-base balance via secretion of H and HCO3 in intercalated cells

Answer 6

Collecting duct

Question 7

Excretory
Acid-base balance
Endocrine
Fluid and electrolyte balance

Answer 7

Functions of kidney

Question 8

Removal of excess fluid and waste
180L of filtrate pass daily – 1-2L removed as urine
Promote homeostasis of blood components

Answer 8

Excretory function of kidney

Question 9

Buffer system to keep pH level around 7.4
Bicarb carries H ions to kidney –> removed from ECF –> reabsorbed in proximal tubule –> returned to blood as needed.

Answer 9

Acid-base balance function of kidney

Question 10

Production of calcitriol
Production of erythropoietin

Answer 10

Endocrine function of the kidney

Question 11

Increased reabsorption of water in collecting duct

Answer 11

Fluid and electrolyte balance function of kidney

Question 12

> /= 90 mL/min
Kidney damage with normal or increased GFR

Answer 12

CKD stage 1

Question 13

60-89 mL/min

Answer 13

CKD Stage 2

Question 14

45-59 mL/min

Answer 14

CKD stage 3a

Question 15

30-44 mL/min

Answer 15

CKD stage 3b

Question 16

15-29 mL/min

Answer 16

CKD stage 4

Question 17

<15 mL/min

Answer 17

CKD stage 5

Question 18

Collection of symptoms with different etiologies
*Proteinuria (>3g/day),
*Hypoalbuminemia
*HTN, HLD
*Edema

Answer 18

Nephrotic Syndrome

Question 19

Avoid excessive protein intake to not exacerbate proteinuria
Sodium restriction
Monitor K and vit D–supplement if needed
Diet changes for associated HLD may not be effective

Answer 19

MNT for Nephrotic Syndrome