Question

Define excretion. Explain mechanism of urine formation.

Answer 1

THE PROCESS OF ELIMINATION OF METABOLIC WASTES FROM THE BODY IS CALLED EXCRETION.URINE FORMATION INCLUDES THREE PROCESSES .FILTRATION,REABSORPTION, SECRETION.THE KIDNEY FILTERS ALL THE BLOOD OF OYR BODY AND EXCRETE UREA AS MAJOR.

Answer 2

Answer:

Explanation:

Excretion is the process of elimination of metabolic waste from the body.

The mechanism of urine formation as follows:-

• Blood enters the glomerulus through the arteriole
• Small molecules like glucose amino acid, nitrogenous waste, ions and water moves from the glomerulus to the glomerular capsule. This result in elimination of large molecules and formed elements from the blood.
• The glomerular filtrate now enters the renal tubule where reabsorption of various nutrient from the filtrate to the blood take place and only a little part of it is added to the urine.
• Now the urine passes into the collecting duct and maximum amount of water gets reabsorbed here. Reabsorption of water is highly dependent on the concentration of antidiuretic hormone(ADH). The addition of urea also takes place here.
• In this way final concentrated urine is formed