Digestion BGI tract componentsAccessory organsDigestive systemBuccal cavityBuccal CavityHard PalateSoft PalateSeparates CavitiesSlide 10Slide 11ArchesOral Cavity Accessory StructuresTeethSlide 15Salivary glandsSalivary GlandsSlide 18Sublingual glandTongueSlide 21PapillaeSlide 23Slide 24Slide 25Taste budsTaste receptorSlide 28Taste receptorsFrenulumSlide 31PharynxSlide 33Slide 34Slide 35SwallowingSlide 37Buccal phaseSlide 39Pharyngeal phaseSlide 41Esophageal phaseSlide 43GlottisEsophagusSlide 46Slide 47PeristalsisEsophagus structureSlide 50Slide 51esophageal sphincterSlide 53Slide 54AchalasiaEsophageal histologyMucosaSubmucosaStomachStomach FunctionsStomach StructureSlide 62Slide 63CardiaFundusBodyPyloric SphincterSlide 68Slide 69Slide 70Slide 71Gastric ulcersStomach RugaeRugaeSlide 75Slide 76StretchyHistologySlide 79Slide 80Gastric PitsGastric GlandsSlide 83Slide 84Gastric secretionsSlide 86Slide 87Slide 88Muscularis ExternaSlide 90Small IntestineSlide 92MesenteriesSlide 94Mesentary FunctionSlide 96Small Intestine StructureDuodenumduodenumSlide 100JejunumSlide 102IleumSlide 104Joins To Large IntestineIleocecal Valve – sphincterMesentariesGreater omentumSlide 109Mesentary ProperSlide 111Mesentery ProperMesocolonSlide 114Large IntestineSlide 116Slide 117Gastric Bypass SurgeryGastric BypassSlide 120Large Intestine structureSlide 122CecumIleocecal valveAppendixSlide 126ColonSlide 128Slide 129Taenia coli & haustraSlide 131Colon faunaSlide 133rectumSlide 135GI Tract HistologySlide 137Slide 138Plicae CircularisSlide 140Slide 141Small Intestine HistologyVilliSlide 144Slide 145Slide 146Slide 147MicrovilliSlide 149Enhance Surface AreaLamina PropriaSlide 152LactealSlide 154Intestinal Histological specializationsSlide 156Duodenum histologySubmucosal (brunner’s) glandsSlide 159Slide 160Duodenal AmpullaSlide 162Slide 163Jejunum HistologyIleum histologyPeyer’s PatchesSlide 167aggregation of WBC’sSlide 169In submucosaSlide 171Digestion BChapter 25GI tract components•Oral cavity (buccal cavity)•Pharynx•Esophagus•Stomach•Small & large intestine (colon/rectum)Accessory organs•Teeth•Tongue•Salivary glands•Liver •Gall bladder•PancreasDigestive systemBuccal cavity–Roof•Hard palate•Maxillary & palatine bones–Soft palate•Fleshy posterior extension•Separates oral & nasal cavity–Floor•Tongue•Skeletal muscle–Posterior•Palatoglossal arches- muscles–Palatine tonsils•Palatopharyngeal arches- muscles•Uvula- extenion of soft palate•Fauces- entrance into pharynxBuccal CavityHard PalateSoft PalateSeparates CavitiesArchesOral Cavity Accessory Structures•Teeth•Salivary glands•Salivary ducts•Tongue•Papillae•Taste buds•frenulumTeeth•Mechanical breakdown of food•Mechanical digestion in buccal cavity•Physical reduction of food size•Churning in buccal cavityTeethSalivary glands•Chemical digestion•Occurs in buccal cavity•Secrete saliva–1-1.5 L/ day•Lubrication •3 primary glands–Parotid•Inf to Zygomatic arch, posterior to masseter–Submandibular•Inf to mandible–Sublingual•Inf to tongue•Salivary ducts–Deliver salivary secretions to oral cavitySalivary GlandsSalivary GlandsSublingual glandTongue•Manipulates food & provides sensory analysis•Mechanical digestion of food in oral cavity •Structure–Skeletal muscle–Covered with modified mucus membraneTonguePapillae•Cone-like projections of thickened epithelium•3 types–Filiform papillae (thread)•Numerous, thin across 2/3 of tongue surface–Fungiform papillae (mushroom)•Medium size, across surface of tongue•Primary Taste structures–Circumvallate papillae (around)•Large size, posterior of tongue•Primary taste structuresPapillaePapillaeTaste buds•Sensory nerve cells lining surface of papillae•Sensitive to 6 taste modalities–Sweet –Sour –Bitter–Salty–Umami–WaterTaste receptorTaste receptorsFrenulum•Tissue anchoring tongue to floor of mouthFrenulumPharynx•Common space where nasal & oral cavity meet•Passageway for both air & ingested substances•3 divisions–Nasopharynx•Superior aspect of pharynx–Oropharynx•Medial aspect of pharynx•Between soft palate & hyoid–Laryngopharynx•Inferior aspect of pharynx•Between hyoid & esophagusLaryngopharynxSwallowing•Deglutition aka “swallowing”•Passage of partially digested food (bolus) from buccal cavity into esophagus•3 stages–Buccal Phase–Pharyngeal phase–Esophageal phaseBuccal phase•Contraction of buccal muscles•Tongue moves food to the back of the oral cavityBuccal phasePharyngeal phase•Contraction of pharangeal muscles•Raises larynx (voice box)•Uvula & soft palate block nasopharynx•Pushes cartilage plate over opening to respiratory passages–Opening= glottis–Cartilage plate= epiglottisSwallowingEsophageal phase•Contraction of esophagus muscles•Moves food bolus thru esophagus to stomach–Massages food down via peristalsisEsophageal phaseGlottisEsophagus•Comprises 1 ft of GI tract•Carries food from pharynx to stomach•Peristalsis –Propells bolus (1-2 sec)–Secretes mucus- lubricates & moistens bolusEsophagusEsophagusPeristalsisEsophagus structure•Posterior to trachea (windpipe)•Passes through mediastinum•Passes through diaphragm–Muscles separating thoracic & abdominal cavities•Exits through lower esophageal sphincter–Smooth muscle ring between stomach & esophagusesophageal sphincteresophageal sphincter•Prevents reflux of stomach (gastric) substances•Improper closing of sphincter–Gastroesophageal reflux disorder (GERD)–Acid reflux- “heart burn” painful irritation of esophagus•Inability to relax sphincter–AchalasiaAchalasiaEsophageal histology•Mucosa–Stratified squamous epithelium•Submucosa–Mucous secreting glandsMucosaSubmucosaStomach•J shaped•Enlargement of tract•Temporary Food storage•Alexis st. martin- 1822Stomach Functions•Protein digestion–initiation•Mechanical digestion & churning•Temporary storage–2-4 hoursStomach Structure•Cardia–Superior region–Surrounds opening to esophageal sphincter•Fundus–Superior & lateral to cardia–Enlarged rounded region–1st storage region•Body–Large central region–Primary storage & churning site•Pyloris–“J” portion, Connects stomach to sm intestineStomachStomachCardiaFundusBodyPyloric SphincterPyloric Sphincter•Smooth muscle ring•Regulates slow entrance of food into intestinePyloric SphincterGastric ulcersStomach