BIOD 151 MODULE 3 WITH CORRECT QUESTIONS AND ANSWERS

BIOD 151 MODULE 3 WITH CORRECT QUESTIONS AND ANSWERS What is the specific function of the salivary gland in the process of digestion? - Food is mixed and moistened with the saliva secreted from the salivary glands that contain enzymes that begin chemical digestion process by breaking down starch. Where are the taste buds located? - Primarily the tongue but also the surface of the mouth and wall of the pharynx. Describe the function of the tongue in the digestive process - tongue grips the food, constantly repositioning it between the teeth and forms the bolus that is pushed back to the pharynx to be swallowed. bolus - compact mass of food formed by chewing of the teeth and reposition by the tongue. three parts of the pharynx - nasopharynx, oropharynx, laryngopharynx through which sections of the pharynx does air travel? food? - air travels through all three sections food travels through oropharynx and laryngopharynx What prevents food from entering the lungs and why is this necessary? - The epiglottis covers the esophagus and prevent aspiration of food and liquid. Describe how the muscular layers in the pharynx assist with food passage. - The two layers of muscle, circumferential outer layer and inner longitudinal layer, alternatively contract to squeeze the food into the esophagus by peristalsis. Tissue layers of the esophagus - the innermost layer is the mucosa which secretes mucus into the interior the gastrointestinal tract, the second layer is the submucosa which contains blood and lymph vessels, lymph nodes, nerves, and mucous glands, the third layer is the muscularis externa which is made of two layers of muscle: the outer longitudinal fibers and inner circumferential fibers and the outermost layer is the serosa which is made up of cells that make serous fluid. Peristalsis - the squeezing of food through the GI tract by the alternating contraction of the sets of longitudinal and circumferential muscles. three main divisions of the tooth - crown, neck, root three types of papillae - filiform, fungiform, circumvallate Which papillae contain taste buds - Circumvallate and fungiform Describe the shape of the stomach and its location relative to the abdomen and diaphragm. - stomach is a backward C-shaped organ located along the left side of the abdomen and below the diaphragm Two divisions of the digestive system - alimentary canal and accessory organs seven parts of the gastrointestinal tract - mouth, pharynx, esophagus, stomach, small intestine, large intestine and anus six digestive accessory organs - teeth, tongue, gallbladder, salivary glands, liver, pancreas mouth opening - lips floor of the mouth - tongue walls of the mouth - cheeks roof of mouth - hard and soft palates two bones and membrane the tongue is attached to - hyoid and mandible bone and membranous lingual frenulum How many teeth are in the human adult and what do they do? - thirty-two teeth work together to tear, crush and grind food to mechanically digest food. What are the four types of teeth? - incisors, canines, premolars, molars incisors - two, chisel shaped for biting canine - one pointed for tearing pre-molars - two fairly flat for grinding molars - three flat