Components of the Digestive System: The digestive system includes the oral cavity, pharynx, esophagus, stomach, small intestine, large intestine, and accessory organs like the liver, pancreas, and gallbladder, all working together to process food and absorb nutrients.
Small Intestine: The small intestine, composed of the duodenum, jejunum, and ileum, is the primary site for digestion and nutrient absorption, featuring villi and microvilli to increase surface area.
Digestive Process: The digestive process involves ingestion, propulsion, mechanical and chemical digestion, absorption of nutrients, and elimination of indigestible substances through defecation.
Histology Small Intestines: The small intestines histology features villi and microvilli on its mucosal surface, which greatly increase the surface area for nutrient absorption; it also contains glands and lymphatic structures for digestion and immune defense.
The Absorptive Stage: During the absorptive stage, which occurs while nutrients are being digested and absorbed, the body uses glucose as its primary energy source and stores excess nutrients as glycogen and fat under the influence of insulin.
