GI System Overview

These flashcards cover key terms and definitions relevant to the gastrointestinal system, including its anatomy, functions, and various processes involved in digestion.

Alimentary Canal

The GI tract that stores, transports, breaks down food; absorbs nutrients; and eliminates waste.

Tunica Mucosa

The inner layer of the GI tract consisting of epithelium, lamina propria, and muscularis mucosa.

Goblet Cells

Cells that secrete mucus found in the epithelium of the GI tract.

Enteroendocrine Cells

Cells that secrete hormones in the GI tract.

Tunica Submucosa

A layer of loose connective tissue in the GI tract that contains glands, blood vessels, and lymphatic tissue.

Meissner's Plexus

A network of nerves in the submucosa that controls local secretion and absorption.

Tunica Muscularis

The layer mostly made of smooth muscle that mixes and crushes food, controlled by the ANS.

Tunica Serosa/Adventitia

The outermost membrane that covers and lubricates organs in the GI tract.

Hepatic Portal System

The blood flow system that shunts nutrient-rich deoxygenated blood from the GI tract to the liver.

Bile

A substance produced by the liver that breaks down fats into smaller pieces.

Chylomicrons

Fat transport particles that enter the lymphatic system rather than blood due to their large size.

Amylase

An enzyme that breaks down starch into disaccharides and monosaccharides.

Gastrin

A hormone secreted by enteroendocrine cells in the stomach that stimulates acid release.

Cholecystokinin (CCK)

A hormone released in response to fat in the duodenum that inhibits GI motility and stimulates bile release.

Microvilli

Small finger-like projections on the surface of intestinal cells that increase surface area for absorption.

Hemorrhoids

Swollen and inflamed veins in the rectum which can cause discomfort and bleeding.

Motility

The ability of the GI tract to move food and liquids through its system.

Enteroendocrine Cells

Cells that produce and secrete hormones like secretin and GIP in the GI tract.