Digestive system part l

Digestive System

The system responsible for the acquisition and processing of nutrients, including the digestive tract and accessory organs.

Gastrointestinal (GI) Tract

The muscular tube that extends from the oral cavity to the anus, including the mouth, pharynx, esophagus, stomach, small intestine, large intestine, and anus.

Anabolism

The use of nutrients to synthesize essential compounds in the body.

Catabolism

The breakdown of nutrients to provide energy for cells.

Accessory Organs

Organs that assist in digestion but are not part of the digestive tract, including teeth, tongue, salivary glands, liver, pancreas, and gallbladder.

Ingestion

The process that occurs when food enters the oral cavity.

Mechanical Digestion

The physical process of breaking down food into smaller pieces through processes like chewing and churning.

Chemical Digestion

The chemical breakdown of food into small organic fragments by acids and enzymes.

Secretion

The release of water, acids, enzymes, buffers, and salts by digestive organs.

Absorption

The process of moving organic molecules, electrolytes, vitamins, minerals, and water across the digestive epithelium into the bloodstream.

Defecation

The elimination of indigestible substances from the body.

Peristalsis

Waves of muscular contractions that move a bolus along the digestive tract.

Segmentation

Cycles of contraction in the digestive tract that churn and fragment the bolus, mixing it with intestinal secretions.

Mucosa

The inner lining of the digestive tract consisting of epithelium, lamina propria, and muscularis mucosae.

Submucosa

A layer of dense irregular connective tissue that binds the mucosa to the muscular layer, containing blood vessels and nerves.

Muscular Layer

Smooth muscle layer involving inner circular and outer longitudinal layers responsible for mechanical digestion and movement.

Serosa

The visceral peritoneum covering the muscular layer of the digestive tract.

Tight Junctions

Structures between epithelial cells that form a barrier to exclude harmful molecules and facilitate nutrient transport.

Enteroendocrine Cells

Cells in the digestive tract that produce hormones influencing various aspects of digestion.