BIO 256 Exam 1 Review Questions and Answers 2023

BIO 256 Exam 1 Review Questions and Answers 2023 function of digestive system processes food, extracts nutrients and eliminates residue the physical breakdown of food into smaller parts mechanical digestion A series of hydrolysis reactions that break dietary macromolecules into their monomers chemical digestion 6 accessory organs teeth, tongue, salivary glands, liver, gallbladder, pancreas what makes up the gi tract stomach and intestines mechanical digestion occurs where grinding of teeth and churning of stomach and small intestine chemical digestion occurs where digestive enzymes produced by salivary glands, stomach, pancreas, and small intestine most absorption occurs where small intestine small mucosal projections that increase surface area for absorption villi permanent transverse folds in the intestinal lining circular folds four layers of the digestive tract mucosa, submucosa, muscularis externa, serosa (from inner to outer) the submucosal plexus is located ____ in the submucosa layer the myenteric plexus is located between two layers of the muscularis externa function of submucosal plexus control glandular secretions of mucosa and movement of muscularis mucosae function of myenteric plexus controls peristalsis and other contractions of muscularis externa what are the three salivary glands parotid, submandibular, sublingual function of saliva begins starch and fat digestion, inhibits bacterial growth, binds food together to form bolus, dissolves molecules to stimulate taste buds two enzymes in the saliva salivary amylase and lingual lipase salivary amylase function begins starch digestion and breaks down polysaccharides lingual lipase function activated by stomach acid and digests fat after food is swallowed and breaks down triglycerides what is deglutination swallowing first phase of swallowing oral phase (voluntary control) second phase of swallowing pharyngeal phase (involuntary control) third phase of swallowing and what occurs here esophageal phase (involuntary control) peristalsis occurs in this phase involuntary wave of muscular contraction that pushes bolus ahead of it peristalsis function of the esophagus actively move food and liquid to stomach lower esophageal location and function end of esophagus and prevents back flow of stomach contents functions of stomach food storage, mechanical digestion, chemical digestion, production of chyme/intrinsic factor parietal cells secrete intrinsic factor and HCl chief cells secrete pepsinogen and gastric lipase glycoprotein that aids in vitamin B12 absorption intrinsic factor HCl function activates pepsinogen, denatures proteins, kills microbes in food pepsinogen function activated by pepsin, breaks down proteins, protein digestion completed in small intestine gastric lipase function plays minor roll in lipid digestion, rest digested in small intestine how is the stomach protected and which cells secrete mucus mucous coat, tight junctions, epithelial cell replacement; and mucosa cells what causes stomach ulcers breakdown of protective measures (mucous coat, tight junctions, epithelial cell replacement) or acid-resistant bacteria (helicobacter pylori) pyloric sphincter location and function at the junction of the stomach and the small intestine; regulates the passage of chyme from the stomach into the small intestine and regulates food movement three layers of smooth muscle in stomach longitudinal, circular, oblique (inner to outer) folds in the stomach name and function rugae; allow gastric expansion functions of small intestine absorbs and digests 90% of nutrients and water localized contractions that mix chyme with digestive juices for absorption segmentations (happens in small intestine) the lacteals (lymphatic capillaries do what absorb chylomicrons in small intestine three parts of small intestine duodenum, jejunum, ileum the small intestine receives _____ from liver and _______ from pancreas bile from liver; pancreatic juices from pancreas starch digesting enzyme secreted by pancreas pancreatic amylase enzymes that digest proteins into peptides in the pancreas trypsin, chymotrypsin, carboxypeptidase, elastase principal fat/lipid/triglyceride digesting enzyme in adults in pancreas pancreatic lipase nucleic acid-digesting enzyme in pancreas ribonuclease digests RNA and DNA in nucleotides in pancreas deoxyribonuclease sodium bicarbonate in pancreas does what is in pancreatic juices that neutralizes the acid that comes from stomach three sections of large intestine colon, rectum and anal canal portion ending at anal canal in large intestine rectum final 3 cm of the large intestine anal canal functions of colon in large intestine drive contents into rectum, formation of feces, absorbs vitamins that are liberated by bacteria, convert proteins into amino acids, produce some B vitamins two sphincters of large intestine and what muscle are they made of internal anal sphincter (smooth) and external anal sphincter (skeletal) functions of liver produce bile, processing of drugs and hormones, excretion of bilirubin, phagocytosis, vitamin D activation and synthesis of bile salts