Major enzyme is Tryptophan Synthase whose activity is reduced when trp concentration is high

TLS Online TPP Program

#Id: 5542

#Unit 7. System Physiology – Animal

The thick ascending limb of the loop of Henle is the site of action of the powerful “loop” diuretics such as

Furosemide

Ethacrynic acid

Bumetanide 

TLS Online TPP Program

#Id: 5543

#Unit 7. System Physiology – Animal

At physiologic pH, the loop diuretics are anions that attach to the Cl−-binding site of the Na+-K+-2Cl− cotransporter.

TLS Online TPP Program

#Id: 5544

#Unit 7. System Physiology – Animal

The thick ascending limb has a sodium-hydrogen counter-transport

TLS Online TPP Program

#Id: 5545

#Unit 7. System Physiology – Animal

In the thick segment of the ascending loop of Henle, paracellular reabsorption of cations, such as Mg++, Ca++, Na+, and K+ occur

TLS Online TPP Program

#Id: 5546

#Unit 7. System Physiology – Animal

Paracellular reabsorption of cations (K+) causes slight positive charge (+8)of the tubular lumen relative to the interstitial fluid

TLS Online TPP Program

#Id: 5547

#Unit 7. System Physiology – Animal

Positive charge forces cations such as Mg++ and Ca++ to diffuse from the tubular lumen through the paracellular space and into the interstitial fluid