Digestive System Overview

These flashcards cover key vocabulary and concepts related to the digestive system as outlined in the lecture notes.

Digestive System Function

To break down food/drink into smaller units of absorbable nutrients, which are used by the body to generate energy.

Alimentary Canal

A long tube (approximately 15-20 feet) that includes structures such as the mouth, esophagus, stomach, small intestine, and large intestine, which break down food.

Peristalsis

An organized contraction and relaxation of smooth muscle layers that propels food through the alimentary canal in one direction.

Mechanical Digestion

Physical breakdown of food particles, including processes like chewing, churning, and segmentation.

Chemical Digestion

The process by which enzymes break down food particles into smaller molecules.

Absorption

The process by which digested particles (like sugars and fatty acids) are transported from the digestive canal into blood and lymph capillaries.

Defecation

The elimination of indigestible products from the body as feces.

Mucosa

The innermost layer of the alimentary canal, which lines the lumen and contains epithelial tissue.

Submucosa

A layer of connective tissue that supports the mucosa and contains blood vessels, nerves, and glands.

Muscularis Externa

The muscle layer of the alimentary canal responsible for peristalsis and segmentation movements.

Serosa

The outer covering of the alimentary canal, consisting of a simple squamous epithelium and loose areolar connective tissue.

Accessory Digestive Organs

Organs like the liver, gallbladder, pancreas, and salivary glands that participate in digestion but do not have food pass through them.

Cholecystokinin (CCK)

A hormone that signals the gallbladder to release bile for fat digestion.

Secretin

A hormone that stimulates the production of pancreatic juice and bile to neutralize stomach acids in the small intestine.

Villi

Small, finger-like projections in the small intestine that increase the surface area for absorption of nutrients.

Goblet Cells

Cells that secrete mucus to protect the epithelium of the digestive tract.

Pancreas

An organ that produces digestive enzymes and bicarbonate to neutralize stomach acid in the small intestine.

Liver

An organ that processes blood, produces bile for fat digestion, and stores nutrients.

Gallbladder

A small organ that stores and concentrates bile produced by the liver.

Esophagus

A muscular tube that connects the pharynx to the stomach, allowing the passage of food.

Celiac Disease

An autoimmune disorder where the ingestion of gluten leads to damage in the small intestine.

Haustra

Pouches in the large intestine formed by contractions of the tenia coli.

Plicae Circulares

Folds of mucosa and submucosa in the small intestine that increase internal surface area for absorption.