Identify in diagrams and images the main organs of the digestive system, limited to: (a) alimentary canal: mouth, oesophagus, stomach, small intestine (duodenum and ileum) and large intestine (colon, rectum, anus) (b) associated organs: salivary glands, pancreas, liver and gall bladder

The main organs of the digestive system can be categorized into two groups: the alimentary canal and associated organs. Below is a description of each organ along with their functions.

(a) Alimentary Canal

1. Mouth
   • Function: The entry point for food where mechanical digestion begins through chewing, and chemical digestion starts with saliva from the salivary glands.
2. Oesophagus
   • Function: A muscular tube that transports food from the mouth to the stomach through peristaltic movements.
3. Stomach
   • Function: A hollow organ that stores food and mixes it with gastric juices to continue the digestion process, breaking down food into a semi-liquid form called chyme.
4. Small Intestine
   • Divisions:
     • Duodenum: The first section where most chemical digestion occurs, receiving bile from the liver and digestive enzymes from the pancreas.
     • Ileum: The final section where nutrient absorption occurs before passing undigested material to the large intestine.
5. Large Intestine
   • Divisions:
     • Colon: Absorbs water and electrolytes from indigestible food matter.
     • Rectum: Stores feces until they are expelled.
     • Anus: The opening at the end of the digestive tract through which feces are excreted.

(b) Associated Organs

1. Salivary Glands
   • Function: Produce saliva that contains enzymes to begin the digestion of carbohydrates and lubricate food for easier swallowing.
2. Pancreas
   • Function: Produces digestive enzymes and bicarbonate, which are released into the small intestine to aid in digestion and neutralize stomach acid.
3. Liver
   • Function: Produces bile, which helps emulsify fats for digestion, and processes nutrients absorbed from the small intestine.
4. Gall Bladder
   • Function: Stores and concentrates bile produced by the liver until it is needed in the small intestine for fat digestion.