Digestion Process Overview

Digestion

• Digestion begins in the mouth with chewing food into smaller pieces
• Saliva from salivary glands contains amylase, initiating carbohydrate digestion, and lipase, initiating fat digestion
• The chewed food forms a bolus
• The bolus travels down the esophagus and through the lower esophageal sphincter into the stomach
• The stomach secretes hydrochloric acid (HCl), pepsin, and gastric lipase
• The stomach churns food into chyme, released into the duodenum through the pyloric sphincter
• The duodenum receives bile from the liver and gallbladder, and digestive enzymes from the pancreas
• Bile aids in fat digestion
• The pancreas secretes pancreatic amylase, pancreatic lipase, trypsin, and chymotrypsin
• Most nutrient absorption occurs in the small intestine
• The small intestine comprises the duodenum, jejunum, and ileum
• The ileum connects to the large intestine via the ileocecal valve
• The large intestine absorbs water and some solutes
• The large intestine consists of the ascending colon, transverse colon, descending colon, and sigmoid colon
• The appendix is a small, finger-like projection from the cecum, the first part of the large intestine
• Feces are expelled through the anus
• The small intestine possesses villi, projections increasing the surface area for absorption
• Villi are covered in microvilli (brush border), further enhancing surface area
• Enterocytes line villi, assisting in nutrient absorption
• The central lacteal within villi absorbs fats into the lymphatic system
• Capillary networks surround each villus, absorbing proteins and carbohydrates and delivering nutrients to the bloodstream

This quiz covers the comprehensive steps of digestion, starting from the mouth to the small intestine. Understand how various organs like the stomach, liver, and pancreas contribute to breaking down food and the absorption of nutrients. Test your knowledge on enzymes and their roles in digestion.