Digestive System

• Digestion begins with chewing or mastication, where food is broken up mechanically to increase its surface area for chemical breakdown.
• Digestion is the breakdown of large molecules into smaller molecules that can be absorbed into the bloodstream
• Mechanical digestion involves physical processes such as cutting, grinding, mixing, churning, and propelling food through the digestive tract.
• The digestive system consists of organs such as the mouth, esophagus, stomach, small intestine, large intestine, rectum, anus, liver, gallbladder, pancreas, salivary glands, and accessory organs like teeth and tongue.
• Chemical digestion is the breakdown of food by the use of enzymes
• Ingestion: the introduction of food into the mouth
• Peristalsis: the involuntary constriction and relaxation of the muscles of the intestine or another canal, creating wave-like movements that push the contents of the canal forward.
• Mastication: The process of chewing food with the teeth and the muscles of the mouth.
• Gastric juice is secreted by the stomach walls and mixed with food
• Hydrochloric acid kills bacteria and activates pepsin
• Pepsinogen is converted to pepsin which breaks down proteins
• Bile from the liver emulsifies fats
• Pepsin breaks down proteins to peptides
• Emulsification: the process by which large, fat droplets are broken down into smaller droplets to increase surface area for chemical breakdown of lipids by lipase
• Maltase breaks down maltose to glucose
• Amylase breaks down starch to maltose
• Lipase breaks down triglycerides to glycerol and fatty acids
• Bile juice neutralizes the acidic chyme to make it less acidic
• The liver produces bile juice that is stored in the gallbladder until needed.
• Absorption is the process by which the products of digestion are taken up into the bloodstream
• Assimilation is the process by which the body utiliizes the nutrients that have been absorbed
• Egestion is the process by which the indigested and