23PharynxEsophagusSlide 4Esophageal CharacteristicsDigestive Processes in the MouthDeglutition (Swallowing)Slide 8PowerPoint PresentationSlide 10Slide 11Slide 12Slide 13Slide 14Slide 15StomachSlide 17Slide 18Slide 19Microscopic Anatomy of the StomachSlide 21Slide 22Slide 23Slide 24Glands of the Stomach Fundus and BodySlide 26Stomach LiningDigestion in the StomachRegulation of Gastric SecretionCephalic PhaseGastric PhaseSlide 32Intestinal PhaseRelease of Gastric Juice: Stimulatory EventsRelease of Gastric Juice: Inhibitory EventsRegulation and Mechanism of HCl SecretionSlide 37Response of the Stomach to FillingSlide 39Gastric Contractile ActivitySlide 41Slide 42Regulation of Gastric EmptyingSlide 44Slide 45Small Intestine: Gross AnatomySlide 47Small Intestine: Microscopic AnatomyDuodenum and Related OrgansSlide 50Small Intestine: Histology of the WallSlide 52Intestinal JuiceLiverSlide 55Liver: Associated StructuresSlide 57Gallbladder and Associated DuctsLiver: Microscopic AnatomySlide 60Slide 61Slide 62Microscopic Anatomy of the LiverComposition of BileThe GallbladderRegulation of Bile ReleaseSlide 67Slide 68Slide 69Slide 70Slide 71Slide 72Slide 73Slide 74Copyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsHuman Anatomy & PhysiologySEVENTH EDITIONElaine N. MariebKatja HoehnPowerPoint® Lecture Slides prepared by Vince Austin, Bluegrass Technical and Community CollegeC H A P T E R23The Digestive SystemP A R T BCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsPharynxFrom the mouth, the oro- and laryngopharynx allow passage of:Food and fluids to the esophagusAir to the tracheaLined with stratified squamous epithelium and mucus glandsHas two skeletal muscle layersInner longitudinal Outer pharyngeal constrictorsCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsEsophagusMuscular tube going from the laryngopharynx to the stomachTravels through the mediastinum and pierces the diaphragm Joins the stomach at the cardiac orificeCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsEsophagusFigure 23.12Copyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsEsophageal CharacteristicsEsophageal mucosa – nonkeratinized stratified squamous epithelium The empty esophagus is folded longitudinally and flattens when food is presentGlands secrete mucus as a bolus moves through the esophagusMuscularis changes from skeletal (superiorly) to smooth muscle (inferiorly)PLAYPLAYInterActive Physiology®:Secretion, page 6Copyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsDigestive Processes in the MouthFood is ingestedMechanical digestion begins (chewing)Propulsion is initiated by swallowingSalivary amylase begins chemical breakdown of starchThe pharynx and esophagus serve as conduits to pass food from the mouth to the stomachCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsDeglutition (Swallowing)Coordinated activity of the tongue, soft palate, pharynx, esophagus, and 22 separate muscle groupsBuccal phase – bolus is forced into the oropharynxCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsDeglutition (Swallowing)Pharyngeal-esophageal phase – controlled by the medulla and lower ponsAll routes except into the digestive tract are sealed offPeristalsis moves food through the pharynx to the esophagusPLAYPLAYInterActive Physiology®:Motility, pages 4-5Copyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsFigure 23.13(d)(e)RelaxedmusclesCircular musclescontract,constrictingpassagewayand pushingbolus downBolus offoodLongitudinalmusclescontract,shorteningpassagewayahead of bolusGastroesophagealsphincter closedStomachRelaxedmusclesGastroesophagealsphincter open(a) (b)(c)TongueTracheaPharynxEpiglottisGlottisUpper esophagealsphincter contractedBolus of foodUpper esophagealsphincter relaxedEpiglottisEsophagusUvulaBolusBolusUpper esophagealsphincter contractedCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsDeglutition (Swallowing)Figure 23.13(a)TongueTracheaPharynxEpiglottisGlottisUpper esophageasphincter contractedBolus of foodCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsDeglutition (Swallowing)Figure 23.13(b)Upper esophagealsphincter relaxedEpiglottisEsophagusUvulaBolusCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsDeglutition (Swallowing)Figure 23.13(c)BolusUpper esophagealsphincter contractedCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsDeglutition (Swallowing)Figure 23.13(d)RelaxedmusclesCircular musclescontract,constrictingpassagewayand pushingbolus downBolus offoodLongitudinalmusclescontract,shorteningpassagewayahead of bolusGastroesophagealsphincter closedStomachCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsDeglutition (Swallowing)Figure 23.13(e)RelaxedmusclesGastroesophagealsphincter openCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsFigure 23.13(d)(e)RelaxedmusclesCircular musclescontract,constrictingpassagewayand pushingbolus downBolus offoodLongitudinalmusclescontract,shorteningpassagewayahead of bolusGastroesophagealsphincter closedStomachRelaxedmuscles(a) (b)(c)TongueTracheaPharynxEpiglottisGlottisUpper esophagealsphincter contractedBolus of foodUpper esophagealsphincter relaxedEpiglottisEsophagusUvulaBolusBolusUpper esophagealsphincter contractedCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsStomachChemical breakdown of proteins begins and food is converted to chymeCardiac region – surrounds the cardiac orificeFundus – dome-shaped region beneath the diaphragmBody – midportion of the stomachPyloric region – made up of the antrum and canal which terminates at the pylorusThe pylorus is continuous with the duodenum through the pyloric sphincterCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsStomachGreater curvature – entire extent of the convex lateral surfaceLesser curvature – concave medial surfaceLesser omentum – runs from the liver to the lesser curvatureGreater omentum – drapes inferiorly from the greater curvature to the small intestineCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsStomachNerve supply – sympathetic and parasympathetic