Digestive System - Video Notes

Vocabulary-style flashcards covering the major organs, processes, enzymes, and common digestive system diseases and conditions described in the video notes.

Digestive System

A group of organs that work together to break down food, absorb nutrients, and remove waste from the body.

Alimentary Canal

The continuous tube (Digestive Tract) that food passes through.

Accessory Organs

Organs that assist digestion but do not directly carry food; they produce or store enzymes and digestive juices.

Liver

Largest internal organ; secretes bile to emulsify fats, aiding digestion.

Bile

Digestive fluid (not an enzyme) that emulsifies fats to form smaller droplets for digestion.

Gallbladder

Stores and concentrates bile and releases it into the small intestine when fat is present.

Pancreas

Produces digestive enzymes (amylase, trypsin, lipase) released into the small intestine.

Pancreatic Amylase

Enzyme that digests carbohydrates in the small intestine.

Trypsin

Pancreatic enzyme that breaks proteins into peptides.

Peptidases

Enzymes that further break peptides into amino acids.

Pancreatic Lipase

Enzyme that digests fats into fatty acids and glycerol.

Mouth (Buccal Cavity)

Entry point for food where digestion starts; mechanical and chemical digestion occur.

Teeth

Incisors, canines, premolars, and molars; responsible for cutting, tearing, and grinding food.

Tongue

Muscular organ aiding in tasting and moving food; contains taste buds.

Taste Buds

Cells on the tongue that perceive tastes.

Salivary Glands

Produce saliva containing enzymes and lubricants for swallowing.

Salivary Amylase

Enzyme in saliva that digests carbohydrates.

Pharynx

Common passageway for air and food.

Epiglottis

Flap that closes over the trachea during swallowing to prevent food from entering the lungs.

Esophagus

Muscular tube that transports food from the pharynx to the stomach via peristalsis.

Peristalsis

Wave-like muscle contractions that move food through the esophagus and intestines.

Bolus

Mass of chewed and mixed food ready to enter the stomach.

Lower Esophageal Sphincter (Cardiac Sphincter)

Muscular ring that prevents stomach contents from re-entering the esophagus; opens to allow food into the stomach.

Stomach

Organ where food is mixed with gastric juice to form chyme.

Gastric Glands

Glands in the stomach that secrete acid and enzymes for digestion.

Chyme

Partially digested, soupy mixture formed in the stomach.

Pyloric Sphincter

Sphincter between stomach and small intestine that controls chyme passage.

Gastric Rugae

Folds in the stomach that allow it to expand when it fills with food.

Small Intestine

Long, coiled tube where digestion completes and most absorption occurs; contains enzymes from the intestinal lining.

Duodenum

First section of the small intestine where chyme mixes with bile and pancreatic juices.

Jejunum

Second section of the small intestine where most nutrient absorption occurs.

Ileum

Third section of the small intestine where absorption continues and bile acids are reabsorbed.

Villi

Finger-like projections lining the small intestine that increase surface area for absorption.

Large Intestine (Colon)

Absorbs water and electrolytes; forms and stores feces.

Ileocecal Valve

Valves between the ileum and the cecum preventing backflow of contents.

Cecum

Beginning section of the large intestine that connects to the ileum.

Rectum

Final section of the large intestine where feces are stored before elimination.

Anus

Opening at the end of the digestive tract through which feces are excreted.

Ingestion

The process of taking food into the mouth.

Mechanical Digestion

Physical breakdown of food (chewing, grinding, churning).

Chemical Digestion

Breakdown of food by enzymes and digestive juices into smaller molecules.

Enzymes

Proteins that speed up chemical reactions to break down substrates.

Absorption

Process by which digested nutrients pass into the bloodstream or lymphatic system.

Assimilation

Use of absorbed nutrients by body cells for energy, growth, and repair.

Excretion

Elimination of waste products from the digestive tract.

Macronutrients

Nutrients required in large amounts to provide energy and support bodily functions.

Carbohydrates

Macronutrient that provides quick energy and is digested into simple sugars.

Fats

Macronutrient that provides high-energy storage and is digested into fatty acids and glycerol.

Proteins

Macronutrient that provides building blocks for growth and repair, digested into amino acids.

Pepsinogen

Inactive enzyme precursor activated to pepsin by acid in the stomach.

Pepsin

Active enzyme in the stomach that digests proteins into peptides.

HCl (Hydrochloric Acid)

Acid in the stomach that activates pepsin and provides an acidic environment.

Chief Cells

Stomach cells that secrete pepsinogen.

Parietal Cells

Stomach cells that secrete hydrochloric acid.

Helicobacter pylori

Bacteria associated with stomach ulcers and gastritis.

GERD (Gastroesophageal Reflux Disease)

Chronic acid reflux due to LES dysfunction, causing heartburn and other symptoms.

LES

Abbreviation for Lower Esophageal Sphincter, controls entry of food into the stomach.

Gallstones

Solid stones formed from bile cholesterol or bilirubin that can block bile flow.

Lactose Intolerance

Inability to digest lactose due to insufficient lactase enzyme.

Rotavirus

Virus that can cause diarrhea via fecal-oral transmission.

Constipation

Condition where stool is dry and difficult to pass due to slow movement in the large intestine.