Renal - Major Factors That Contribute To The Buildup Of Solute Concentration Into The Renal Medulla

Front 1

Major Factor 1

Back 1

Active transport of sodium ions and co-transport of potassium, chloride, and other ions out of the thick portion of the ascending limb of the loop of Henle into the medullary interstitium

Front 2

Major Factor 2

Back 2

Active transport of ions from the collecting ducts into the medullary interstitium

Front 3

Major Factor 3

Back 3

Facilitated diffusion of large amounts of urea from the inner medullary collecting ducts into the medullary interstitium

Front 4

Major Factor 4

Back 4

Diffusion of only small amounts of water from the medullary tubules into the medullary interstitium

Front 5

Major Factor 5

Back 5

Sets up gradient effect of the gross structure of kidney- have to maintain that with a very low GFR

Front 6

Low vasa recta (located in the juxtamedullary) blood flow required to maintain medullary hypertonicity makes the tubule region vulnerable to ischemia

What are the regional blood flow rates (mL/min per gram tissue)

Back 6

Cortex (4-5 mL/min)

Outer medulla (.7-1 mL/min)

Inner medulla (.2-.25 mL/min)

Front 7

Nephron Summary
(how nephron does its job of reabsorbing 124 mL/min)

What are the proximal events?

Back 7

o Large volume reabsorbed
o Necessary nutrients reabsorbed
o Bicarbonate reabsorbed
o Less fine tuning
o All events are isomotic (not really an osmotic gradient from proximal tubule cells into interstitium)

Front 8

Nephron Summary
(how nephron does its job of reabsorbing 124 mL/min)

What are the distal events and what happens in the Loop of Henle?

Back 8

o Smaller volumes reabsorbed
o more active transport (mitochondria)
o hormonal control ( the later you go in the nephron, the more that the hormones (vasopressin and aldosterone) can influence reabsorption)
o fine tuning of body sodium, water, potassium, pH
o various sties are targets of diuretic action
o urine concentration