CBSE Class 7 Answered

Hi Virat,

Waste materials are present in the blood, and hence, a mechanism to filter blood is needed which is performed by the blood capillaries in the kidneys. Of the useful and harmful substances in the blood which reach the kidneys, the useful substances are reabsorbed into the blood. The wastes dissolved in water are removed as urine. From the kidneys, the urine goes into the urinary bladder through tube-like ureters. The bladder stores urine till the time it is passed out through the urinary opening at the end of a muscular tube called urethra.

Sweat is also a type of excretory product containing water and salts. It is removed from the body by sweat glands through the skin. Sweat evaporates from our body taking the heat required for evaporation from the body; in this way, the body loses heat and makes us feel cool.