Excretory System: Class 10 II Life Processes II Excretion in Humans and Plants II Free Study Material II LetsBloom study material

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The biological process involved in the removal of these harmful metabolic wastes from the body is called excretion.

In Unicellular Organisms

Many unicellular organisms remove these wastes by simple diffusion from the body surface into the surrounding water

In Multicellular Organisms

Multi-cellular organisms use specialized organs to perform the function of Excretion.

PARTS OF EXCRETORY SYSTEM:


How is urine produced?

  • The urine is produced by filtering out waste products from the blood.
  • Nitrogenous waste such as urea or uric acid are removed from blood in the kidneys.
Process of Excretion
  • The basic filtration unit in the kidneys is Nephron.
  • The basic filtration unit in the kidneys, is a cluster of very thin-walled blood capillaries around Nephron.
  • It comprises of cup-shaped or U-shaped end of a coiled tube called Bowman’s capsule that collects the filtrate and tube-shaped

  • tubule.
  • Dirty blood from body enters Bowman's capsule and filter out by glomerulus, so that Red Blood Cells and other things larger in size are removed out.
  • The filtered-out material- Filtrate containing glucose, amino acids, salts and a major amount of water flows along the tube.
  • In tubule these materials are selectively re-absorbed and enters the nearby capillaries.
  • The amount of water re-absorbed depends on how much excess water there is in the body, and on how much of dissolved waste there is to be excreted.
  • The urine forming in each kidney eventually enters a long tube, the ureter, which connects the kidneys with the urinary bladder. Urine is stored in the urinary bladder until the pressure of the expanded bladder leads to the urge to pass it out through the urethra. The bladder is muscular, so it is under nervous control.
EXCRETION IN PLANTS:

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