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A&P IV Midterm Exam Review PacketCh. 24DIGESTIVE PROCESSES
GI TRACT AND ACCESSORY DIGESTIVE STRUCTURESBE ABLE TO IDENTIFY EACH ORGAN ON THE IMAGE ABOVE.GI TRACT INNERVATIONAutonomic NSoParasympathetic NV (enhances digestion)oSympathetic NV (inhibits or slows down digestion)Enteric Nervous SystemoSubmucosal plexusoMyenteric plexus
Be able to identify all parts of the GI tract What are the histological significances of the GI tract?The GI tract consist of 4 layers: Mucosa- Divides into 3 layers Epithelium – Surface EpitheliumLamina Propria – Connective TissueMuscularis Mucosae – Smooth MuscleSubmucosa- Areolar Connective TissueMuscularis- In all GI tract organs except the stomachSerosa
ENZYMES originating in the oral cavityWhat are the functions of the oral cavity? Salivary glandsParotid glands (under the cheek bones)Submandibular glands (under the mandible)Sublingual glands (under the tongue)AllsecreteSALIVA, whichcontains:oMostly wateroIonsoBuffersoLysosymeoSalivary amylaseSalivary Amylase (made by thesalivary glands)-Break down carbohydrates-Converts Polysaccharides to monosaccharides, maltose, maltotrioseand alpha-dextrins-Deactivatedby stomach acidLingual Lipase (made by thelingual glands of the tongue)-From lingual glands of the tongue-Break down lipids-Activatedby HClof stomach-Converts triglycerides to fatty acids and monoglycerides-What are the components of saliva?
Among these polynucleotides, what is digested in the oral cavity? (proteins, lipids, nucleic acids, THE SIGNIFICANT CELLS OF THE STOMACH AND THEIR SECRETIONS (GASTRIC JUICE)Parietal Cells-Secrete HCl-makes the chyme acidic-kills bacteria-denaturing (unfolding) proteins-activates pepsinalong with linguallipase.-Secrete intrinsic factor, which allows for absorption of vitamin B12 Chief Cells-The major stomach cells-Secrete pepsinogen,which is activated (by stomach acid) and becomes pepsin, a peptidase-Pepsinbreaks down proteins-Secrete gastric lipase-breaks down triglyceridesinto monoglyceridesand fattyacidsG Cells-Secrete Gastrin(hormone): contracts cardiac sphincter; loosens pyloric sphincter; promotes stomach motility; promotes secretion of pepsinogen from chief cells and HCl from parietal cellsMucous Cells-THEY SECRETE MUCOUS-Mucous forms a protective barrier against acidic chyme