What is the primary function of the glomerulus?

What is the primary function of the glomerulus?

• A. Site of filtration
• B. Site of reabsorption
• C. Site of secretion
• D. Storage of urine

Answer: (A)

Filtration of blood plasma is the main function of the glomerulus. Within the renal corpuscle, blood enters specialized glomerular capillaries and is forced through a filtration barrier that lets water and small solutes pass into Bowman's space, forming the filtrate. Large proteins and blood cells are retained in the bloodstream because of size and charge restrictions of the barrier. This filtration step is the first stage of urine formation, and the filtrate then moves on to the tubules where most reabsorption and some secretion occur to produce the final urine. So, the glomerulus is the site where plasma is filtered into a filtrate, not where reabsorption, secretion, or urine storage happens. Reabsorption and secretion happen later along the renal tubules, and urine storage occurs in the urinary tract and bladder.

Filtration of blood plasma is the main function of the glomerulus. Within the renal corpuscle, blood enters specialized glomerular capillaries and is forced through a filtration barrier that lets water and small solutes pass into Bowman's space, forming the filtrate. Large proteins and blood cells are retained in the bloodstream because of size and charge restrictions of the barrier. This filtration step is the first stage of urine formation, and the filtrate then moves on to the tubules where most reabsorption and some secretion occur to produce the final urine. So, the glomerulus is the site where plasma is filtered into a filtrate, not where reabsorption, secretion, or urine storage happens. Reabsorption and secretion happen later along the renal tubules, and urine storage occurs in the urinary tract and bladder.