Because the are unable to pass through a semipermeable membrane such as a capillary.
nephrons
nephrons
exocytosis
They are the nephrons that really fine tune the level of concentration of the urine.
The filtering units within the kidney are called nephrons.
urea
nephrons
nephrons
The filtering unit of the kidney is the nephrons.
cortical nephrons
There are about 1 million nephrons in a kidney. Most humans have 2 kidneys.
Deamination
exocytosis
serum
Nephrons in kidney .
They are the nephrons that really fine tune the level of concentration of the urine.
Why are nephrons surrounded by many tiny blood vessels