CBSE Class 10 Answered

Metabolic wastes are removed from the body with the help of nephrons.

• The blood which enters the kidney through the renal artery contains waste substances as well as useful substances.
• The nephrons remove the wastes such as excess water, mineral salts and urea from the blood.
• The glomerular filtrate consists of water, urea, salts, glucose and other plasma solutes.
• Blood corpuscles, proteins and other large molecules remain behind in the glomerulus.
• The glomerular filtrate entering the renal tubule contains many useful substances.
• Hence, as the filtrate passes down the tubule, water and other substances required by the body are reabsorbed.
• The filtrate left after reabsorption and tubular secretion is called urine.
• The urine passes from the collecting duct to the pelvis of the kidneys. From there, it is sent to the urinary bladder through the ureters.
• By relaxing the sphincters present at the opening of the urethra, the urine is expelled out of the body. This process is known as micturition or urination.