Gastrointestinal System Anatomy Quiz

Overview

• The gastrointestinal (GI) system, also known as the digestive system, is a complex system responsible for breaking down and absorbing nutrients from food.

Mouth

• Mouth cavity (buccal cavity)
  • Food enters the mouth, where it is chewed by teeth and mixed with saliva that contains enzymes to break down carbohydrates.
  • The tongue helps mix food with saliva and forms a bolus for swallowing.

Esophagus

• Esophagus
  • A muscular tube that carries food from the mouth to the stomach through peristalsis, a wave-like muscle contraction.
  • The lower esophageal sphincter (LES) regulates the passage of food into the stomach.

Stomach

• Stomach
  • A sac-like organ that secretes digestive enzymes and acids to break down proteins and fats.
  • The stomach lining has rugae (folds) and is lined with mucous membranes to protect it from acid digestion.
  • Gastric juices contain:
    • Pepsin: breaks down proteins
    • Hydrochloric acid (HCl): creates an acidic environment
    • Mucin: protects the stomach lining

Small Intestine

• Small intestine (small bowel)
  • A long, thin tube where most nutrient absorption takes place.
  • The walls of the small intestine have finger-like projections called villi, which increase the surface area for absorption.
  • Nutrients are absorbed into the bloodstream and transported to the liver for processing.

Pancreas and Bile Ducts

• Pancreas
  • Produces digestive enzymes that break down carbohydrates, proteins, and fats.
  • Secretes bicarbonate-rich fluids to neutralize stomach acid.
• Bile ducts
  • Bile produced in the liver is stored in the gallbladder and released into the small intestine to emulsify fats.

Large Intestine

• Large intestine (colon)
  • Absorbs water and electrolytes, and stores and eliminates waste.
  • The colon is home to a diverse microbiome that helps with fermentation and immune system function.

Accessory Organs

• Liver
  • Produces bile, filters blood, and regulates metabolism.
• Gallbladder
  • Stores and concentrates bile from the liver.
• Rectum and anus
  • The rectum stores feces until they are eliminated through the anus during defecation.

Gastrointestinal System

• The GI system is responsible for breaking down and absorbing nutrients from food.

Mouth

• The mouth cavity is where food is chewed by teeth and mixed with saliva that contains enzymes to break down carbohydrates.
• The tongue helps mix food with saliva and forms a bolus for swallowing.

Esophagus

• The esophagus is a muscular tube that carries food from the mouth to the stomach through peristalsis, a wave-like muscle contraction.
• The lower esophageal sphincter (LES) regulates the passage of food into the stomach.

Stomach

• The stomach is a sac-like organ that secretes digestive enzymes and acids to break down proteins and fats.
• The stomach lining has rugae (folds) and is lined with mucous membranes to protect it from acid digestion.
• Gastric juices contain:
  • Pepsin, which breaks down proteins
  • Hydrochloric acid (HCl), which creates an acidic environment
  • Mucin, which protects the stomach lining

Small Intestine

• The small intestine is a long, thin tube where most nutrient absorption takes place.
• The walls of the small intestine have finger-like projections called villi, which increase the surface area for absorption.
• Nutrients are absorbed into the bloodstream and transported to the liver for processing.

Pancreas and Bile Ducts

• The pancreas produces digestive enzymes that break down carbohydrates, proteins, and fats.
• The pancreas secretes bicarbonate-rich fluids to neutralize stomach acid.
• Bile produced in the liver is stored in the gallbladder and released into the small intestine to emulsify fats.

Large Intestine

• The large intestine absorbs water and electrolytes, and stores and eliminates waste.
• The colon is home to a diverse microbiome that helps with fermentation and immune system function.

Accessory Organs

• The liver produces bile, filters blood, and regulates metabolism.
• The gallbladder stores and concentrates bile from the liver.
• The rectum stores feces until they are eliminated through the anus during defecation.