BMAT - Biology - Digestion, Excretion, Circulatory System Review Questions and Answers

What is the structure of the digestive system? What is the function of the oeophagus? Carries food from mouth to stomach What is the function of the stomach? muscular sac with an inner layer that produces enzymes. Its role is to store and digest food, especially proteins. It has glands that produce enzymes which digest protein. What is the function of the ileum? long muscular tube. Food is further digested in the ileum by enzymes that are produced by its walls and by glands that pour their secretions into it. The inner walls of the ileum are folded into villi, which gives them a large surface area. The surface area of these villi is further increased by millions of tiny projections, called microvilli, on the epithelial cells of each villus. This adapts the ileum for its purpose of absorbing the products of digestion into the bloodstream. What is the function of the large intestine? Absorbs water What is peristalsis? Mouth - food chewed iin to small pieces by the teath and mixed with saliva. tongue rolls food in to soft mass called bolus. Swallowing the tongue moves up to push bolus towards pharynx, the soft pallet moves up to prevent bolus entering nasal cavity. Epiglosis lowers to stop opening to trachea Bolus enters oesophagus, wall of oesophagus consists of circulat and longitudinal mucles. Circular contract behind and longitudial relax, in from C relaxes and L contracts - this wave like movement is peristalsis What is the function of the rectum? Final section of intestines where the feaces are stored before egestion What are the enzymes present in digestion? amylase - salivary breaks down starch to maltose - made in salivary glands membrane bound disaccharide maltase - turns maltose to glucose in the illeum Pepsin - breaks down proteins to amino acids in the stomach - produces in the stomach Trypsin - produced in the pancreas breaks down proteins Pancreatic lipase breaks apart fats in the intestines and ileum Salivary lipase - from salivary glands breaks down liipids Things like mineral salts and bile to keep neutral