Question

After filtrate has been formed, it is further processed to create urine. Follow some filtrate through the renal tubule (up to and including the collecting duct), explaining what processes take place in each region of the renal tubule. What are the normal constituents of urine at the end of this process?

Answer 1

In proximal convuluted tubule all the essential nutrients like glucose,vitamins are reabsorbed.Almost 70 % of the water and sodium is reabsorbed.In descending limb of loop of henley it is not permeable to sodiuma permeable to water ,so as the osmolarity increases from 300mosm/l to 1200mosm/L.In the ascending limb of Henley loop is almost permeable to sodium and impermeable to water,hence the osmolarity decrease to 300mosm/L.The loop of henley is useful in maintaining the osmolarity of the medullary interstitium.Distal convuluted tubule is for water and sodium reabsorption under harmone influence. Collecting duct is also for water reabsorption.The normal constituents of urine at the end of the process are urea, creatinine,some water