Renal Pathology

Question 1

What are the Main Functions of the Kidney?

Answer 1

• Maintain Water Balance
• Regulate the quantity and concentration of the ECF ions
• Maintain plasma volume
• Acid-base balance
• Excrete waste products
• Secretion of renin, erythropoietin, etc

Question 2

What are the 3 main cells of the Glomerulus?

Answer 2

-Podocytes, Mesangial Cells, and Endothelial Cells

Question 3

How do Mesangial Cells help to keep out plasma proteins?

Answer 3

they are responsible for laying down the glomerular basement membrane that is negatively charged

Question 4

What is the normal physiological GFR?

Answer 4

100-125 ml/min

Question 5

Formula For Calculating GFR?

Answer 5

GFR = Kf (HPc - πc - HPbs)

Question 6

How does Tubuloglomerular feedback in work to regulate Renin levels?

Answer 6

1. )↑ pressure in afferent arteriole inhibits renin release from JG cells, ↓ pressure promotes renin relase
2. )B1-adrenergic nerves timulate renin relase (green arrows)
3. )Increased NaCl in distal nephron inhibits renin release (red arrows), decreased load promotes renin release

Question 7

Acute Renal Failure

Answer 7

a sudden decrease in glomerular filtration rate, resulting in an increase in plasma concentration of waste products (azotemia) normally excreted by the kidneys

Question 8

Where is ARF usually contracted? What is the mortality rate in these populations that contract it?

Answer 8

ARF almost always evolves in the hospital, in 1% to 25% of critically ill patients. Mortality in these populations ranges from 28% to 90%.

Question 9

ARF is characterized by

Answer 9

• reducted production of urine
• retention of water, H+, and minerals, resulting in metabolic acidosis
• retention of metabolic waste products in the blood, most notably BUN and creatine

Question 10

oliguria

Answer 10

reduced urine production

Question 11

anuria

Answer 11

no urine production

Question 12

What are the three types of Acute Renal Failure?

Answer 12

• Pre-Renal
• Post-Renal
• Parenchymal Renal Disease

Question 13

Pre-Renal ARF

Answer 13

• decreased renal perfusion,reduction in blood flow,
• could be caused by loss in blood volume & blood pressure
• caused by shock, heart failure, or hemmorrage

Question 14

Post-Renal

Answer 14

• obstruction to urine flow, nephrons can’t drain

- could be kidney stones, bladder problems, prostrate cancer, pinching off ureter

Question 15

Parenchymal Renal Disease

Answer 15

Intra Renal Disease, means the problem is with the kidney itself and not flow to the kidney

Question 16

Pre-Renal ARF (Pre-Renal azotemia) pathogenesis?

Answer 16

Any process that sharply decreases renal perfusion

• Hypotension
• Volume depletion (fluid loss, bleeding, etc.)
• Primary cardiac pump failure
• Decreased systemic vascular resistance (sepsis)

Question 17

Response to renal hypoperfusion in Pre-Renal ARF?

Answer 17

↓ GFR => ↑ Ang II, ↑ ADH, ↑ Aldosterone

-Na and water retention

Question 18

In Pre-Renal ARF what happens to BUN/creatine levels?

Answer 18

Increase, especially BUN reabsorption which will increase the BUN : Creatinine ratio

Question 19

Best way to treat Pre-Renal ARF?

Answer 19

improve renal perfusion!!!

-Volume replacement, dialysis