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Defaecation

9.5 Defaecation 
 
This image explains the defaecation process and is divided into five sections: Function of the Large Intestine: Absorbs water and vitamins (e.g., Vitamin B, K, and folic acid) and forms faeces from undigested food, dead cells, and waste. Absorption Process: Water and minerals are absorbed, and byproducts from bacteria (e.g., Vitamin B and K) are also absorbed. Formation of Faeces: Faeces consist of waste, dead cells, bile pigments, and bacteria. Mucus smoothens the movement of faeces. Defaecation Process: Rectum muscles contract to push faeces out through the anus. Movement of Faeces: Takes 12-24 hours to reach the rectum, and pressure triggers the need to expel faeces. The center highlights the word DEFAECATION and the logo Pandai.
 
Function of The Large Intestine
  • After the absorption of nutrients is completed in the ileum, undigested food, dead cells, epithelial cells, fibre and water enter the large intestine and move slowly through peristaltic action.
  • Fibre consists of cellulose walls of plant cells.
  • The large intestine carries out two main functions:
    • Absorption of water and vitamins.
    • Formation of faeces.
Absorption of Water and Vitamins
  • Substances absorbed are
    • Water and mineral salts
    • Metabolic byproducts of some bacteria such as：
      • Vitamin B
      • Vitamin K
      • Folic acid
Formation of Faeces
  • After the water is absorbed, the remaining waste is a semisolid called faeces.
  • Faeces contains dead cells from the inner layer of the intestine, waste products such as bile pigments, bacteria and toxic substances.
  • The walls of the large intestine secrete mucus to smoothen the movement of faeces until the anus.
  • The movement of faeces takes about 12 to 24 hours before entering the rectum.
  • The faeces will accumulate in the rectum until the pressure in the rectum increases and triggers the need to expel faeces from the body.
  • The rectum muscles will contract to expel faeces from the anus.
  • This process is called defaecation.
 
 
The views expressed in the notes here are those of the contributor and don’t necessarily represent the views of Pandai.

Defaecation

9.5 Defaecation 
 
This image explains the defaecation process and is divided into five sections: Function of the Large Intestine: Absorbs water and vitamins (e.g., Vitamin B, K, and folic acid) and forms faeces from undigested food, dead cells, and waste. Absorption Process: Water and minerals are absorbed, and byproducts from bacteria (e.g., Vitamin B and K) are also absorbed. Formation of Faeces: Faeces consist of waste, dead cells, bile pigments, and bacteria. Mucus smoothens the movement of faeces. Defaecation Process: Rectum muscles contract to push faeces out through the anus. Movement of Faeces: Takes 12-24 hours to reach the rectum, and pressure triggers the need to expel faeces. The center highlights the word DEFAECATION and the logo Pandai.
 
Function of The Large Intestine
  • After the absorption of nutrients is completed in the ileum, undigested food, dead cells, epithelial cells, fibre and water enter the large intestine and move slowly through peristaltic action.
  • Fibre consists of cellulose walls of plant cells.
  • The large intestine carries out two main functions:
    • Absorption of water and vitamins.
    • Formation of faeces.
Absorption of Water and Vitamins
  • Substances absorbed are
    • Water and mineral salts
    • Metabolic byproducts of some bacteria such as：
      • Vitamin B
      • Vitamin K
      • Folic acid
Formation of Faeces
  • After the water is absorbed, the remaining waste is a semisolid called faeces.
  • Faeces contains dead cells from the inner layer of the intestine, waste products such as bile pigments, bacteria and toxic substances.
  • The walls of the large intestine secrete mucus to smoothen the movement of faeces until the anus.
  • The movement of faeces takes about 12 to 24 hours before entering the rectum.
  • The faeces will accumulate in the rectum until the pressure in the rectum increases and triggers the need to expel faeces from the body.
  • The rectum muscles will contract to expel faeces from the anus.
  • This process is called defaecation.
 
 
The views expressed in the notes here are those of the contributor and don’t necessarily represent the views of Pandai.
Chapter : Nutrition and Digestive System of Humans
Topic : Explain the functions of the large intestine: (i) absorption of water and vitamins, (ii) formation of faeces
Form 4 Biology
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