Lecture 1 - Kidney Intro

Question 1

The high ______ pressure in glomerular capillaries drives filtration of blood into Bowman’s capsule (about 20% of Renal Plasma Flow - RPF - or 180L is filtered per day). About 178-179L of this fluid is reabsorbed.

Answer 1

Hydrostatic pressure

Question 2

While most electrolytes are regulated more so via _______, K+ and H+ are more so regulated via _______.

Answer 2

Reabsorption

Secretion

Question 3

The _____ convoluted tubule reabsorbs about 66% of Na+ and H2O, mainly via _______ transport. This convoluted tubule is freely permeable to ______ but not ______. As H2O is reabsorbed, the solute concentration INSIDE the tubule increases –> drives solute reabsorption. _____ junctions in this tubule have high permeability –> facilitates Paracellular transport of ____, ____, and _____.

Answer 3

Promixmal (PCT)

Transcellular

H2O but not Na+

Tight junctions

K+, Ca++, and Urea

Question 4

The _____ convoluted tubule also reabsorbs MOST of the HCO3-, ALL nutrients, and about 80% of ______.

Answer 4

Proximal (PCT)

Phosphate

Question 5

The PCT secretes weak ____ and ____ via ______ transport which are important for the elimination of drugs and foreign compounds.

Answer 5

Acids and Bases

Trancellular

Question 6

The thin descending limb of the Loop of Henle (tDLH) does not have ANY _____ transport.

Answer 6

Active transport

Question 7

The thin ascending limb of the Loop of Henle (tALH) also lacks active transport and is impermeable to _____.

Answer 7

H2O

Question 8

The Thick Ascending Limb of the Loop of Henle (TAL) is impermeable to _____ (so the entire ascending limb is impermeable to it), but it does have transcellular active transport. Specifically, it has the ________ exchanger that is the target for _____ (which diuretics?).

The TAL reabsorbs about 25% of _____. It also reabsorbs ____ and ____ via paracellular transport.

Answer 8

H2O

Na+/K+/Cl- exchanger

Loop (i.e. Furosemide)

Na+

Ca++ and Mg++

Question 9

The Distal convoluted tubule (DCT) also plays a small role in reabsorption of _____, and is the target for ______ diuretics. It is impermeable to _____, and it has Transcellular active transport of _____.

Answer 9

Na+

Thiazide

H2O

Ca++

Question 10

The ______ Collecting duct is comprised of _____ cells (acid/base balance) and _____ cells (Na+ reabsorption - regulated by which hormone? - and K+ secretion).

Which of these cells is the target for K+ sparing Diuretics?

Answer 10

Cortical Collecting Duct

Intercalated cells

Principal cells –> Na+ is regulated by Aldosterone here

Principal cells are the target for K+ sparing diuretics.

Question 11

The medullary Collecting duct is comprised of the Outer and Inner segments. The Outer has regulated _____ permeability via _____ (which hormone?). The Inner has regulated _____ and _____ permeability.

Answer 11

H2O

ADH

H2O and Urea