Question

How is the function of the kidney greatly dependent on the process of osmosis?  If there was a high amount of vasopressin, what happens regarding osmosis along the collecting duct? Include how are the regional differences (medulla vs. cortex) of the kidney are involved and the function of juxtamedullary nephrons.

Answer 1

Kidney cells has semipermeable membrane throughout and the osmosis actively facilitates the removal of metabolic waste products beacause osmosis allows the liquid solvents to pass through the semipermeable membranes. The high salt concentration is the characteristics of interstitial fluid .The interstitial fluid present outside the nephron provides the driving force for osmosis and therefore retention of water from the filterate occurs further.

Vasopressin functions on renal collecting tubule via V2 receptor and tends to increases the water permeability /osmosis.Our body system has unique way to control the high amount of vasopressin,the osmosis process will faster in collecting tubule and will be able retain more water from the filterate inside body.As a result, the highly concentrated urine will be excreted out.

The cortex region of the nephron contains shorter loop of henle which is present in the outer medulla region of nephron whereas the juxtamedullar nephron contains long loop of henle embedded in the inner medulla region of the nephron.