1. Upper Digestive Tract:
* Mouth: This is where mechanical digestion (chewing) and chemical digestion (with saliva) begin.
* Pharynx: This is the passageway from the mouth to the esophagus.
* Esophagus: This muscular tube carries food from the pharynx to the stomach.
2. Lower Digestive Tract:
* Stomach: This muscular organ churns and mixes food with gastric juices, beginning the breakdown of proteins.
* Small Intestine: This is the primary site of nutrient absorption. It's divided into three segments:
* Duodenum: This receives partially digested food from the stomach and mixes it with bile and pancreatic juices.
* Jejunum: The primary site of nutrient absorption.
* Ileum: Continues nutrient absorption and connects to the large intestine.
* Large Intestine: This is responsible for absorbing water and electrolytes, forming and storing feces. It's divided into four segments:
* Cecum: Connects to the small intestine and houses bacteria.
* Colon: The main part of the large intestine, where water absorption occurs.
* Rectum: Stores feces before elimination.
* Anus: The opening for the elimination of feces.
3. Accessory Organs:
* Liver: Produces bile, which aids in fat digestion.
* Gallbladder: Stores and concentrates bile.
* Pancreas: Secretes digestive enzymes and hormones that regulate blood sugar.
These subsystems work in a coordinated fashion to break down food, absorb nutrients, and eliminate waste. Each part plays a critical role in maintaining our overall health.
