Alimentary canal

• Swallowing moves food from the mouth to the stomach through the pharynx and esophagus.
• The stomach secretes hydrochloric acid and digestive enzymes that continue the breakdown of food begun in the mouth.
• Digestion involves mechanical breakdown (chewing) and chemical breakdown (enzymes).
• The digestive system is responsible for breaking down large molecules into smaller ones that can be absorbed by cells lining the intestines.
• Food is then moved into the small intestine, where most nutrient absorption occurs.
• The large intestine absorbs water and electrolytes from undigested material.
• Waste products are eliminated as feces.
• Chemical breakdown occurs when salivary amylase begins breaking down carbohydrates as soon as they enter the oral cavity.
• Gastric juice contains pepsinogen, an inactive form of the protein-digesting enzyme pepsin.
• Mechanical breakdown occurs when food is chewed, mixed with saliva, and ground up by teeth.
• Pancreatic juice contains bile produced by the liver and stored in the gallbladder.
• Chemical breakdown begins in the mouth with the action of amylase on carbohydrates and continues in the stomach with the secretion of hydrochloric acid and pepsinogen.
• The alimentary canal consists of the oral cavity, pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus.
• Enzymes are proteins that catalyze biochemical reactions without being altered or used up during the reaction.
• Lipase breaks down lipid into fatty acids and glycerol.
• Bile emulsifies fat droplets to increase surface area for pancreatic lipases to act on them.
• Bile produced by the liver helps emulsify fats so that lipases can break them down more easily.