Concise Selina Solutions for Class 9 Biology Chapter 11 Digestive System


The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion. Digestion involves the breakdown of food into smaller and smaller components until they can be absorbed and assimilated into the body. The digestive processes are ingestion, propulsion, mechanical digestion, chemical digestion, absorption, and defecation. The GI tract is a series of hollow organs joined in a long, twisting tube from the mouth to the anus. The hollow organs that make up the GI tract are the mouth, esophagus, stomach, small intestine, large intestine, and anus. The liver, pancreas, and gallbladder are the solid organs of the digestive system.