Alimentary Canal Overview

Alimentary Canal

• The alimentary canal, also known as the digestive tract, is a long tube that starts at the mouth and ends at the anus.
• It is responsible for the digestion and absorption of food.

Mouth

• The mouth is the first part of the alimentary canal.
• Food is chewed and mixed with saliva.
• Saliva contains the enzyme salivary amylase which helps break down starch into simpler sugars like maltose.
• The tongue helps mix the food with saliva.

Esophagus

• The esophagus is a muscular tube that connects the mouth to the stomach.
• Peristalsis, a wave-like muscular contraction, moves food down the esophagus.

Stomach

• The stomach is a muscular pouch that stores, mixes, and churns food with gastric juice.
• Gastric juice contains hydrochloric acid and enzymes.
• Gastric glands in the stomach wall secrete gastric juice.
• The stomach breaks down large food molecules into smaller, absorbable ones.

Small Intestine

• The small intestine is divided into three segments: duodenum, jejunum, and ileum.
• Enzymes from the liver and pancreas continue breaking down food in the small intestine.
• The liver produces bile, which helps digest fats.
• The pancreas produces pancreatic juice containing enzymes for various food groups.
• The small intestine's inner wall has villi, finger-like projections that absorb digested food and water.

Liver

• The liver is the largest gland in the body.
• It secretes bile, a digestive fluid that helps break down fats.

Pancreas

• The pancreas secretes pancreatic juice, which contains enzymes that help digest carbohydrates, proteins, and fats.

Large Intestine

• The large intestine absorbs water and stores waste material.
• The large intestine leads to the rectum, which continues to absorb water.
• Feces are eliminated through the anus (defecation).