Digestive System Overview

Flashcards covering key vocabulary and concepts related to the digestive system.

Mouth

Ingestion and mechanical digestion (chewing), initial chemical digestion (saliva).

Pharynx

Pathway for food from mouth to esophagus; initiates swallowing.

Esophagus

Transports food from the pharynx to the stomach.

Stomach

Mechanical and chemical digestion (acid and enzymes break down food).

Small Intestine

Absorption of nutrients (amino acids, sugars, fatty acids).

Large Intestine

Absorption of water and electrolytes; formation of feces.

Rectum/Anus

Elimination of waste products.

Teeth

Mechanical breakdown of food.

Salivary Glands

Produce saliva, which moistens food and starts the breakdown of starches.

Liver

Produces bile for fat digestion.

Gallbladder

Stores and concentrates bile.

Pancreas

Secretes enzymes for digestion and bicarbonate to neutralize stomach acid.

Ingestion

Intake of food.

Secretion

Release of digestive enzymes, acid, and other substances to aid digestion.

Propulsion

Movement of food through the digestive tract (e.g., peristalsis).

Digestion

Breakdown of food into smaller molecules; mechanical involves physical breakdown, and chemical involves enzymatic breakdown.

Absorption

Uptake of nutrients into the bloodstream.

Elimination

Removal of indigestible substances as feces.

Mucosa

Inner lining of the GI tract, involved in absorption and secretion.

Submucosa

Contains blood vessels, lymphatics, and nerves.

Muscularis externa

Two layers of muscle responsible for peristalsis.

Serosa/Adventitia

Outer layer; serosa is a smooth membrane, adventitia is connective tissue.

Enteric Nervous System (ENS)

Network of nerves controlling GI function.

Myenteric Plexus (Auerbach’s Plexus)

Controls motility (muscle contractions).

Submucosal Plexus (Meissner’s Plexus)

Regulates enzyme secretion, blood flow, and absorption.

Greater Omentum

Stores fat, limits infections.

Lesser Omentum

Connects the stomach and liver, stabilizes the position of organs.

Mesentery

Supports the small intestine, contains blood vessels.

Mesocolon

Supports the large intestine.

Falciform Ligament

Attaches the liver to the anterior abdominal wall.

Deglutition

The act of swallowing.

Rugae

Folds in the stomach lining that allow for expansion.

Pyloric Sphincter

Regulates the flow of chyme into the duodenum.

Pancreatic Juice

Contains digestive enzymes and bicarbonate to neutralize stomach acid.

Bile

Produced in the liver for fat digestion.

Hepatic Portal Vein

Carries blood to the liver, enters from the digestive tract.

Common Bile Duct

Releases bile from the liver into the duodenum.

Villi

Finger-like projections in the small intestines that increase surface area for absorption.

Taenia Coli

Three bands of smooth muscle in the large intestine that aid in peristalsis.

Haustra

Pouches formed by the taenia coli in the colon.

Brush Border Enzymes

Located on the microvilli of enterocytes, finalize the breakdown of carbohydrates and proteins.

Defecation Reflex

Reflex involving stretch receptors in the rectum leading to relaxation of anal sphincters.

Cephalic Phase

Preparatory phase involving sensory stimuli triggering digestive secretions.

Gastric Phase

Food entering the stomach triggers enzyme and acid secretion.

Intestinal Phase

Controls the rate of stomach emptying into the small intestine.