'OZ' - The 'Other' Side of the Rainbow: FYI - "It's alimentary, my dear Watson!"

Friday, August 15, 2025

FYI - "It's alimentary, my dear Watson!"

The alimentary canal, also known as the digestive tract or gastrointestinal (GI) tract, is the continuous tube through which food passes in the body, from ingestion to excretion. It plays a crucial role in digesting food, absorbing nutrients, and eliminating waste.

Main Components of the Alimentary Canal (in order):

Mouth
- Where digestion begins.
- Mechanical digestion happens through chewing, and chemical digestion begins with enzymes in saliva (e.g., amylase for starch).
Pharynx (Throat)
- Connects the mouth to the oesophagus.
- Involved in swallowing; a small flap called the epiglottis prevents food from entering the windpipe.
Oesophagus
- A muscular tube that moves food to the stomach using rhythmic contractions called peristalsis.
Stomach
- A muscular organ where food is mixed with gastric juices (acid and enzymes like pepsin).
- Begins protein digestion and converts food into a semi-liquid called chyme.
Small Intestine
- Duodenum, jejunum, and ileum are the three parts.
- This is the primary site of digestion and nutrient absorption.
- Enzymes from the pancreas and bile from the liver aid digestion here.
Large Intestine (Colon)
- Absorbs water, minerals, and vitamins from the remaining indigestible food matter.
- Hosts gut bacteria that help in fermentation of waste.
- Forms and stores faeces.
Rectum and Anus
- The rectum stores faeces.
- The anus is the final part of the canal, through which waste is eliminated during defecation.

Supporting Organs (not part of the canal but essential):

Salivary glands – produce saliva.
Liver – produces bile.
Gallbladder – stores and releases bile.
Pancreas – secretes digestive enzymes and bicarbonate into the small intestine.