The figure given below shows a part of a nephron. Answer the questions that follow: The figure given below shows a part of a nephron. Answer the questions that follow:
What is the technical term for the process that occurs in part 3?
Topic: Ultrafiltration
Answer
ULTRAFILTRATION.
Part 3 is the GLOMERULUS, where blood is filtered under HIGH PRESSURE. Water, glucose, amino acids, urea and salts are forced out into Bowman’s capsule, while the blood cells and the large plasma PROTEINS are held back.
The prefix ULTRA- means the filtration is unusually fine — fine enough to separate small molecules from large ones.
THE CONSEQUENCE worth knowing: finding PROTEIN in the urine (albuminuria) means the filtering membrane has been damaged, since proteins should never get through.
Ultrafiltration is the FIRST of the three steps of urine formation, followed by selective reabsorption and tubular secretion.