BGYC33/CC4 Study Guide, Lectures 19-20 (2011)
Lecture 19: Urine Formation and Acid-Base Balance
The Medullary Osmotic Gradient
The Loop of Henle
The Vasa Recta
Water Handling by the Collecting Duct
Water Removal by the Vasa Recta
Overview of Respiratory and Metabolic Acid-Base Disturbances
Acid-Base Regulation by the Respiratory System
Acid-Base Regulation by the Renal System
Acid-Base Regulation in the Proximal Tubule (Bicarbonate Reabsorption)
Acid-Base Regulation in the Distal Tubule (Bicarbonate Synthesis)
Acid-Base Regulation in the Proximal Tubule during Severe Acidosis
1) Which of the following is an important driving force for the reabsorption of water in the kidney?
a) Colloid osmotic pressure in the Loop of Henle.
b) Colloid osmotic pressure in the vasa recta.
c) Osmotic pressure in the Loop of Henle.
d) Hormonally-triggered insertion of aquaporin 3 into the collecting duct.
e) Colloid osmotic pressure of the peritubular fluid.
2) The major limiting factor in the ability of the kidney to concentrate urine is?
a) The activity of ADH.
b) The length of the Loop of Henle.
c) The permeability of the vasa recta.
d) The permeability of the collecting duct.
e) The relative water or ion permeability in the different regions of the Loop of Henle.
3) Which of the following is not a feature of acid-base regulation by the proximal tubule?
a) HCO c3n be reabsorbed.
b) HCO c3n be synthesised.
c) Na can be reabsorbed.
d) H can be secreted.
e) None of the above. 2
4) Why is there no HCO reabsor3tion by the distal tubule?
a) There are no HCO /Cl exchangers in the distal tubule.
b) There is no carbonic anhydrase in the distal tubule cells .
c) The distal tubule is impermeable to CO . 2
d) There is very little filtered HCO in the3distal tubule.
e) The distal tubule is impermeable to HCO . 3-
5) What is the role of the vasa recta?
6) What is a countercurrent exchanger? What is a countercurrent multiplier?
7) Why is the colloid osmotic pressure in the vasa recta critical to kidney function?
8) Why is the colloid osmotic pressure of the vasa recta greater than that in the tubular fluid or the
9) What is ADH? What is its role? What regulates its release? 3
Lecture 20: Acid-Base Balance: Analysis of Davenport Diagrams
Buffering of Plasma Versus Whole Blood
Overview of Acid-Base Disturbances
Uncompensated Acid-Base Disturbances