Digestive System Overview PDF

Digestive system ​ Supplies the fuel and the building blocks for your body ​ Digestive tract ○​ Gastrointestinal Tract (GI tract) or alimentary canal ​ Oral cavity ​ Ingestion, mechanical digestion, ​ accessory organs-...

Digestive system ​ Supplies the fuel and the building blocks for your body ​ Digestive tract ○​ Gastrointestinal Tract (GI tract) or alimentary canal ​ Oral cavity ​ Ingestion, mechanical digestion, ​ accessory organs- ○​ Teeth and tongue ​ Moistening, mixing with saliva ​ Pharynx ​ Muscular propulsion of materials into the esophagus ​ Esophagus ​ Transport of materials to the stomach ​ Stomach ​ Chemical digestion of materials by acids and enzymes ​ mechanical digestion through muscular contractions ​ Small intestine ​ Enzymatic digestion and absorption of water, organic substrates, vitamins, and ions ​ Large intestine ​ Dehydration and compaction of indigestible materials in preparation for elimination ​ Various accessory organs ​ Teeth ○​ mechanical digestion by mastication (chewing) ​ Tongue ○​ Assists mechanical digestion with teeth and sensory analysis ​ Salivary glands ○​ Secretion of lubricating fluid containing enzymes that break down carbohydrates ​ Liver ○​ Secretion of bile, storage of nutrients, many other vital functions ​ Gallbladder ○​ Storage and concentration of bile ​ Pancreas ○​ Exocrine cells secrete buffers and digestive enzymes, and endocrine cells secret hormones ​ Peritoneal cavity ○​ Lined by peritoneum ​ 2 parts ​ 1. Visceral peritoneum ​ 2. Parietal peritoneum  ​ Peritoneal fluid ○​ Some organs supported by mesenteries ​ Mesenteries ○​ Stabilize position ○​ Provide pathway ​ Blood vessels ​ Nerves ​ Lymphatics ○​ Mesenteries to know ​ Falciform ligament ​ Separates the liver into right and left lobes ○​ Greater omentum ​ Lies anterior to abdominal viscera ​ Pouch extends between body wall and small intestine ​ Hangs from lateral and inferior borders of stomach ​ Provides ​ Padding, protection, insulation, and energy reserves ○​ Lesser omentum ​ a thin, double-layered sheet of peritoneum that extends from the liver to the stomach and duodenum ○​ Mesentery proper ​ attaches the small intestine (jejunum and ileum) to the posterior abdominal wall ​ Suspends all but 1st 25cm of small intestine ​ Duodenum and pancreas are retroperitoneal (behind peritoneum) ○​ Mesocolon ​ Associated with large intestine ​ Ascending, descending, and rectum fuse to body wall ​ Transverse mesocolon and sigmoid mesocolon ○​ Intraperitoneal ​ Located within peritoneum ○​ Retroperitoneal ​ Behind peritoneum ​ Generalized wall of the digestive tract ○​ 4 layer wall ​ 1. Mucosa ​ Innermost facing lumen ​ 3 layers ○​ 1. Epithilium ​ Simple or stratified ○​ 2. Lamina propria ​ Layer of tissue that contains blood vessels, arteries, veins, nerve endings, scattered lymphatic tissue  ○​ 3. Muscularis mucosae ​ Sheet of smooth muscle and elastic muscle ​ 2. Submucosa ​ Dense irregular connective tissue ​ Binds mucosa to the muscular wall ​ Blood vessels and lymphatics ​ Exocrine glands in some regions ○​ Secret buffers and enzymes into the lumen ​ Submucosal neural plexus ○​ Inervates mucosa and submucosa ​ 3. Muscularis ​ 2 layers ○​ 1. Inner circular wall ​ Incirculas the lumen ○​ 2. Outer longitudinal layer​ ​ Parallel muscle fibers ​ Similar to submularis mucose ​ Myenteric plexus ○​ Network of nerves that control the muscles of the GI tract ​ Intramural plexus=myenteric + submucosal ​ 4. Serosa ​ Serous membrane ​ Convers digestive tract in peritoneal cavity ​ Adventitia ○​ Fibrous sheeth ○​ Modification of layers ​ 4 wall layers specialized to fit location along the digestive tract ​ Various epithelial in mucosa ​ Extra layers of muscle ​ Glands in various segments ​ Esophagus ○​ Mucosa:stratified squamous epithelium resirs abrasions ○​ Muscularis: 2 layers-​ ​ inner circular with striated muscle ​ Outer longitudinal layer- Smooth muscle ○​ Serosa: Outer layer, fibrous (aventita), serous around part of the esophagus in the thoracic cavity ​ Stomach ○​ Mucosa: arranged inflexible longitudinal folds call rugae ​ Rugae allows for distension, contains gastric pits with microscopic gastric glands ○​ Muscularis: 3 layers ​ 1. Circular ​ 2. Longitudinal  ​ 3. Oblique fibers ​ 2 spinchters- lower esophageal spincter (LES) at the entrance of the stomach and Pylortic sphincter at its exit, formed by circular fibers ○​ Serosa: Outer layer, vesceral peritoneum; hangs in a double fold from the lower edge of the stomach over the intestines and forms an apron-like structure, greater omentum, lesser omentum connected the stomach to the liver ​ Small intestine ○​ Mucosa: Contains permanentie circular folds ○​ Muscularis: 2 layersof inner circular and longitudinal fibers ○​ Serosa: Outer layer visceral peritoneum, continuous with mesentery ​ Large intestine ○​ Mucosa: Solitary lymph nodes; intestinal mucosa glands; anal columns form in the anal region ○​ Muscularis: Outer logitiudinal layer, cicular muscle ○​ Serosa: Outer layer visceral peritoneum, continuous with mesocolon ​ Movement ○​ Motility ​ 1. Perstalis (movement forward) ​ 2. Segmentation ( ​ Ring-like regions that contract in intervals ​ Regions go back and forth contracting and relaxing ​ Chopping and mixing contents ​ Oral cavity ○​ Buccal cavity ​ Sensory analysis of food ​ Mechanical digestion ​ Lubrication ​ Limited chemical digestion ​ Oral mucosa ​ Stratified squamous epithelium ○​ Keratinized in areas exposed to severe abrasion ​ Hard and soft palates ​ Tongue ​ Buccal fat pads and buccinator muscle ​ Lips ○​ Philtrum ​ Runs from the top of the lips to the nose ​ Vestibule ○​ Space between the lips, cheek, in the mouth  ​ Gingivae ​ Fauces ○​ Narrow opening between the mouth and the throat ​ Uvula guards opening to pharynx ○​ 2 pharyngeal arches to each side of the uvula ​ 1. Palatoglossal ​ Soft tissue ridge in the throat from the soft plate to the base of the tongue ​ 2. Palatopharyngeal ​ Soft palate to the pharynx ​ Palatine tonsils between ○​ Tounge ​ 4 primary functions ​ 1. Mechanical digestion ​ 2. Manipulating food to assist chewing and swallowing ​ 3. Sensory analysis ​ 4. Secretion of mucins and lingual lipase ​ Body → oral portion ​ Root → pharyngeal portion ​ Lingual papillae on dorsum ​ Lingual frenulum on inferior midline ​ Plica fimbriata → fimbriated folds ​ Lingual vein ​ 2 groups of skeletal muscles ​ 1. Extrinsic tongue muscles ○​ Move and position the tongue ​ 2. Intrinsic tongue muscles ○​ Control shape and size ​ Both are under the control of the CN XII hypoglossal ○​ Teeth ​ 3 main regions ​ 1. Crown ​ 2. Neck ​ 3. Root ​ Gingival sulcus ​ Periodontal membrane ​ Periodontal ligaments → provide support ​ Pulp cavity ​ Contains blood vessels and nerves ​ Mastication or chewing ​ 4 special connective tissue/dental tissue ​ 1. Pulp ○​ Innermost layer with nerves, blood vessels, and connective tissues  ​ 2. Dentin ○​ Beneath the enamel and makes up most of the tooth ​ 3. Cementum or cement ○​ Holds the root in place and surrounds the root ​ 4. Enamel on the occlusal surface ○​ Hard white outer layer that protects from damage. ​ Types of teeth ​ Dentition ​ 20 primary or deciduous teeth ○​ Name or capital letter ​ 32-28 permanent teeth ○​ Name or Arabic numeral ○​ Clockwise (Top R → L → bottom L → R) ​ Primary teeth lack premolars (bicuspids) and 3rd molars ○​ Salivary glands ​ 3 major pairs secrete into the oral cavity ​ 1. Parotid - 25% ○​ Parotid duct to vestibule at 2nd upper molar ​ 2. Sublingual - 5% ○​ Sublingual ducts along the lingual frenulum ​ 3. Submandibular - 70% ○​ Submandibular ducts immediately posterior to bottom teeth ​ Minor salivary glands in submucosa mainly secrete mucous ​ Saliva ​ 99% water, electrolytes (Na, Cl, HCO3), buffers, glycoproteins, igA antibodies, Enzymes, and wastes ​ pH of the mouth is 7 ​ igA and lysozyme control oral bacteria ​ Salivary amylase and lingual lipase ​ Pharynx ○​ Throat ​ Common passageway ​ Stratified squamous epithelium ​ 3 regions ​ 1. Nasopharynx ​ 2. Oropharynx ​ 3. Laryngopharynx ​ Esophagus ○​ Begins inferior to cricoid cartilage of the larynx at C6 ○​ Posterior to trachea and heart ○​ 3 regions ​ 1. Cervical ​ Runs through the neck ​ 2. Thoracic  ​ Through the thorax/chest ​ 3. Abdominal ​ Past the diaphragm into the abdomen ○​ Esophageal hiatus ​ Small opening in the diaphragm that allows the esophagus to pass through to the stomach ○​ Folded mucosa and submucosa ○​ Muscularis with both skeletal and smooth muscle portions ​ Superior ⅓ ​ Middle ⅓ ​ Inferior ⅓ ○​ Lack serosa - retroperitoneal ○​ A pair of sphincters close off at both ends of the esophagus ​ Upper esophageal sphincter (UES) ​ Cervical portion ​ Prevents air entering during respiration ​ Lower esophageal sphincter or cardiac sphincter ​ Prevents food from entering the esophagus ​ Swallowing/Deglutition ○​ 3 phases ​ 1. Buccal ​ Compression of the bolus ​ Retraction of the tongue ​ 2. Pharyngeal ​ Bolus comes into contact with the palatal arches ​ Uvula and soft palate block passage through the nasopharynx ​ 3. Esophageal ​ Contraction of the pharyngeal muscles force the bolus into the esophagus ​ The bolus is pushed into the stomach ○​ Starts as voluntary and then becomes involuntary ○​ Proceeds automatically in pharynx and esophagus ​ Swallowing reflex ​ Tactile cues on palatal arches and uvula ​ Swallowing centers in the medulla ​ CN V trigeminal and glossopharyngeal CN IX ​ Stomach ○​ A tubular organ in the upper left quadrant of the peritoneal cavity ​ Temporary store food ​ Mechanically digest food ​ Chemically digest food ○​ Chyme ​ Food bolus, partially digested food, gastric juices ○​ Lesser curvature  ​ Cardia to pylorus ○​ Greater curvature ​ On lateral surface ○​ Typically extends between T7 and L3 ○​ 4 regions ​ 1. Cardia ​ Connected to esophagus ​ 2. Fundus ​ Top rounded part to the left of the cardia ​ 3. Body ​ Largest and main part ​ Food is mixed and starts to break down ​ 4. Pyloric ​ Connects to the small intestine ○​ Pyloric sphincter ○​ Cardiac sphincter or lower esophageal sphincter ○​ Rugae ○​ Oblique layer ○​ Stomach histology ​ Simple columnar epithlium ​ Gastric pits ​ Gastric glands ​ Parietal cells ​ Parietal cells indirectly produce HCL ​ Produce H+ and Cl- separately ​ Produce carbonic acid and transports bicarbonate ​ Actively transport hydrogen into stomach ​ Chloride shift moves bicarbonate out and chlorine in ​ Chief cells ​ Secrets digestive enzymes ​ Digestion and absorption in the stomach ○​ Permits continued digestion of the carbohydrates via salivary amylase and lingual lipase ○​ preliminary digestion of proteins ○​ Very little absorption of nutrients ​ Most absorption is in the small intestine ○​ Some drugs and alcohol are absorbed in the stomach and before nutruience ​ Small intestine ○​ Where chemical digestion is completed and products absorbed ○​ 3 segments ​ 1. Duodenum - 25 cm (10in) ​ A lot of digestion occurs ​ 2. Jejunum 2.5 m (8.2ft) ​ 3. Ileum 3.5 m (11.5ft)  ​ Transitions into large intestine ○​ small intestine ends at Ileocecal valve ○​ Wall of small intestine ​ Circular folds or plica circulares ​ Permit folds that significantly increase surface area for absorption ​ Intestinal villi ​ Finger-like projections into the lumen of the small intestine and contain microvilli ​ Simple columnar epithelia with microvilli ​ Brush border ○​ Brush border enzymes that help with digestion ​ Nerves, capillaries, and lacteals in each villus ​ Regional specializations ○​ Intestinal glands ​ At base of villi ​ Intestinal crypts ​ Stem cells ​ Paneth cells ​ Enteroendocrine cells ​ Submucosal mucous glands ○​ Intestinal control ​ Neural and hormonal control ​ Duodenal submucosal glands ​ Local reflexes ​ Parasympathetic stimulation ​ Sympathetic inervation inhibits secretion ​ Myenteric reflexes ​ Enetrogastic reflex ​ Hormones from the digestive tract can enhance or suppress reflexes ​ Pancreas (accesory organ)(exocrine pancreas) ○​ Posterior to stomach ○​ Sceretes digestive enzymes and buffers ○​ Head in bend of duodenum ○​ Body 15 cm(6 in) long ○​ Tail ○​ Retroperitoneal ○​ Pancreatic duct ○​ Accessory pancreatic duct in 3-10% of population ○​ Joins bile duct ​ Hepatopancreatic ampulla ○​ Enters duodenum at duodenal papiilla ○​ pancreatic acini → simple cuboidal ○​ Islets only account for approximately 1% of cell population ○​ Pancreatic juice  ​ Contains digestive enzymes ○​ Pancreatic enzymes do most of the digestive work ○​ Hormones from dudenum control secretion ​ Secretin ​ Cholecystokinin (CCK) ○​ Pancreatic enzymes ​ Pancreatic alpa amalayes ​ Pancreatic lipase ​ Nucleases ​ Proteolytic enzymes ​ Liver ○​ Largest visceral organ ○​ Inferior to diaphragm ○​ R hypochondriac and epigastric regions ○​ Wrapped in a tough fibrous capsule ○​ Covered by a layer of visceral peritoneum ○​ 4 lobes ​ 1. Right lobe ​ 2. Left lobe ​ 3. Caudate lobe ​ 4. Quadrate lobe ○​ Falciform ligament and round ligament ○​ Hilum also known as porta hepatitis ○​ connective tissue divides each lobe into 100,000 lobules ○​ Interlobular septum separates adjacent lobules ○​ Hexagonal shape ○​ Hepatocytes arranged in irregular plates ○​ Sinusoids between plates drain into central vein ​ Draining blood ○​ Stellate macrophages (kupffer cells) in sinusoids ○​ 6 portal triads ​ Interlobular portal vein (branch of hepatic portal vein) ​ Interlobular artery (branch of hepatic portal artery) ​ Interlobular bile duct ○​ Bile duct system ​ Bile caniliculi ​ Combine with bile ductules ​ Travel to portal triads ​ Right and left hepatic ducts ​ Common hepatic ducts ​ Flows into either ○​ Bile ducts ​ Joining cystic duct and common hepatic duct ​ Empties into duodenal (hepatopancraetic) ampulla  ​ Empities duodenum via major duodenal papilla ○​ Cystic duct ​ Leads to gallbladder ○​ Liver physiology ​ Carries out over 200 functions ​ 3 categories ​ 1. Metabolic regulation ​ 2. Hematological regulation ​ 3. Bile production ​ Secrete and store bile (700-1,200 mL per day) ​ Metabolism of lipids, carbohydrates, and proteins ​ Immunity – Stellate macrophages (Kupffer cells) ​ Secretes clotting factors ​ Stores blood ​ Stores glycogen ​ Stores vitamin B12, E, A, and K ​ Stores minerals ​ Detoxifies hormones, toxins, and drugs ​ Produces plasma proteins – fluid balance ​ Converts ammonia (NH4) to urea ​ Gallbladder ○​ Hollow, pear-shaped organ ○​ Stores and consecrates bile ○​ Fossa on the posterior surface of right lobe of liver ○​ Fundus, body, and neck connecting to the cystic duct ○​ Hepatopancreatic sphincter ​ Large intestine ○​ Stores and compacts digestive waste ○​ Reabsorbs water ○​ Absorbs vitamin from bacteria ○​ Divided into 3 parts ​ 1. Cecum ​ Expanded pouch in the lower right quadrant ​ Material arriving from Ileum ​ Ileocecal valve ​ Appendix or vermiform appendix ​ Meso-appendix ○​ Small mesentery that connects the cecum to the appendix ​ 2. Colon ​ Large diameter and thinner walls than small intestine ​ Haustra ​ 3 teniae coli ​ Omental appendices or fatty appendices of colon or epiploic appendages  ​ Divided into 4 segments ○​ 1. Ascending colon ​ Just superior to the cecum ○​ 2. Transverse colon ​ Curve anteriorly from hepatic flexure and cross the abdomen from right to left ○​ 3. Descending colon ​ Inferiority along left side until iliac fossa ○​ 4. Sigmod colon ​ S-shaped ​ Posterior to the urinary bladder ​ Supported by transverse mesocolon ○​ Superior and inferior mesenteric artery and vein ​ 3. Rectum ​ Final 15-20 cm or 8-12 inches of the digestive tract ​ Anal canal ​ Anal columns ​ Distal transverse folds mark epithelial transitional ​ Ends in anus ​ Hemorrhoid plexus ​ 2 sphincter ○​ 1. Internal anal sphincter ​ Circular smooth muscle ​ Involuntary control ○​ 2. External anal sphincter ​ Skeletal muscle ​ Conscious control ​ Elimination ○​ Expulsion of feces from the digestive tract ○​ Defecation ○​ Stimulation of receptors in rectal mucosa ○​ Distention of rectum ​ Reflexive relaxation of internal anal sphincter ​ Desire to defecate ○​ Consious relaxation of external anal sphincter ​ Contraction of colonic smooth muscle ​ Residues of digestion ○​ Feces ​ Cellulose ​ Undigested connective tissues ​ Mostly collagen ​ Lack enzymes to hydrolyze ​ Undigested fats ​ Bacteria  ​ Pigments ​ Water ​ Mucous ​ Large intestine histology ○​ Large lymphoid nodules in lamina propria ○​ Longitudinal layer of muscularis reduced as Teniae coli ○​ Lack villa ○​ Abundance of goblet cells ○​ Distinct intestinal glands ​ Large intestine physiology ○​ Absorption and reabsorption in the large intestine ​ Water ​ Vitamins ​ Salts ​ Approx 10% of nutrient reabsorption ​ Absorption ○​ Transcellular absorption ​ Across cells ○​ Paracelluar absorption ​ Passive ○​ Mostly occurring in the small intestine ​ But not entirely ​ Carbohydrates ○​ Starts in the mouth and ends in the small intestine brush border ○​ Salivary amylase ○​ Pancreatic Alpha-amylase ○​ Function best at pH 6.7-7.5 ○​ salivary amylase breaks starch down into disaccharides and trisaccharides ○​ Pancreatic alpha-amylase continues digestion in the duodenum ○​ Brush border enzymes in microvilli break carbs into monosaccharides ​ Maltase ​ Breaking down maltose ​ Sucrase ​ Breaking down sucrose ​ Lactase ​ Breaking down lactose ○​ Absorption by the intestinal epithelium ○​ Monosaccharides cross the intestinal epithelium by ​ Contransport ​ Sodium ​ Facilitated diffusion ○​ Facilitated diffusion out basal epithelium into villi capillaries ○​ In the hepatic portal vein ​ Lipids  ○​ Starts in mouth and ends in the intestines ○​ Lingual lipase ​ Begins the process ○​ Pancreatic lipase ​ Assisted by bile salts ○​ Triglycerides → one glycolic molecule +3 fatty acids ○​ Water soluble enzymes interact with insoluble lipids ○​ Bile salts emulsify Lipids in the duodenum ○​ Form lipid-bile salt complexus called micelles ○​ Able to diffuse into intestinal epithelia ○​ Synthesize new triglycerides in cytoplasm ○​ Coat fat-soluble substances with proteins ○​ Chylomicrons ​ Secreted from intestinal cells by exocytosis ​ Too large to fit into capillaries ​ Most diffuse into intestinal lacteals ​ Cisterna Chyli → Thoracic duct → L Subclavian vein ○​ Most Bile salts will be reabsorbed by sodium-linked cotransport ​ Proteins ○​ Mechanical processing in the oral cavity ○​ Chemical processing in the stomach ​ Acids disrupt tertiary and secondary structure ​ Expose peptides to enzymes ○​ Pepsin ​ Requires low pH 1.5-2.0 ○​ When Chyme enters the duodenum ​ Enteropeptidase from the small intestine ​ Conversion of trypsinogen to trypsin ○​ Buffers raise pH to 7-8 ​ Pancreatic peptidases can work at this pH ​ Trypsin ​ Chymotrypsin ​ Elastase ○​ Carboxypeptidase ​ Responsible for breaking off the last amino acid ○​ Epithelial surface of the small intestine contains dipeptidases ​ Breaking short peptide chains into individual amino acids ○​ Break peptides into single amino acids (AAs) ○​ Contransport and facilitated diffusion just like carbohydrates ​ Apical and basal surface ○​ Hepatic portal vein ​ Nucleic Acids ○​ Broken down by brush border enzymes ○​ Sugars, phosphates, and nitrogenous bases absorbed via active transport  ○​ A very small fraction of nutrients absorbed each day ​ Water, Ions, and Vitamins ○​ Water ​ Passive flow down osmotic gradients ​ Small intestine and more in large intestine ○​ Ions ​ Multiple transport mechanisms ​ Diffusion. Cotransport and active transport ○​ Vitamins ​ Water soluble ​ Most absorbed via diffusion ​ B12 requires intrinsic factors and active transport ​ Fat-soluble ​ Enter with lipids dissolved in triglycerides ​ Digestive system aging ○​ Tooth enamel and dentin deteriorate → Mastication ○​ Taste buds decline in number⇒ Taste altered ○​ Sense of smell decreases → sense of smell ○​ Salivary secretion decreases → digestive process ○​ Gastric motility may be reduced → digestive process ○​ Protective mucosal barrier of stomach decreases → damage to the lining of stomach ○​ Change in intestinal microbiota ○​ Size of Peyer’s patches decreases → Immune function ○​ Villi shorten → absorption ○​ Intestinal absorption, motility, and blow flow decrease ○​ Rectal muscle mass decreases → elimination/constipation ○​ Decreased hepatic regeneration ○​ Ability to detoxify drugs decreases ○​ Secretion of digestive enzymes decreases ○​ Division rate of stem cells decrease and cancer risk increases Study guide Know how different macromoles are digested Know where mysteries are and where they connect ​ Primary Job of the digestive system ○​ Provide the building blocks and fuel you need ​ The digestive system plays a secondary role as an adaptive immune system ○​ False (its innate body does) ​ Cavity in torsal surrounded by a membrane ○​ Partitoneal ​ Lines body cavity  ○​ Pariotalperitonial ​ Soundounds organs ○​ Visceralperiotonial ​ Call double sheet of peritoneal membrane that connects the 2 layer ○​ Mesentery ​ Found in spaces between parietal and visceral ○​ Peritoneal fluid ​ Supporing organs mesintary supports pathways for blood vessels nerves and lymphatics ○​ T ​ Which mesintary separtes the lobes of the liver ○​ Falciform ligament ​ Which missionary hangs as a pounh anterior to the abdominal visceral ○​ Greater omentum ​ Which military is found between liver and stimach ○​ Lesser omentum ​ mesentery supports most of the small intestine ○​ Mesintary proper ​ Which mesentary supports large intestine that passes across the top of the abdominal cavity (transverse colon) ○​ Transverse mesocolon ​ Which mesentery supports connection between the colon and rectum ○​ Sigmoid mesocolon ​ What term describes all organs within the peritoneal cavity ○​ Intraperitoneal ​ What term describes all organs outside the peritoneal cavity ○​ Retroperitoneal ​ Which layer of digestive tract lines the lumen ○​ Mucosa ​ A layer of tissue that contains blood vessels, arteries, veins, nerve endings, scattered lymphatic tissue ○​ Lamina propria ​ The epithelial of digestive is simple columnar except for the rectum ○​ False ​ Muscularis mucosa is found in the muscular layer of the digestive tract ○​ False (found in mucosa) ​ The muscularis mucosa has… ○​ Smooth muscle and elastic fibers ​ Layer is made of dense regular connective tissue and acts as a connection for teh two layers ○​ Submucosa ​ Call the nerves in the submucosal layer ○​ Submucosaplexus ​ Which layer of the digestive contains metric plexus ○​ Muscularis ​ Which layer is the serous membrane on the surface of the diesgive tract ○​ Serosa ​ Serosa is only found on the part of the digestive tract that are within the peritoneal cavity ○​ True ​ T or F There are pacesetter cells in the muscularis mucosa that regulate motility ○​ True ​ What term moves food through the diesfgive tracy ○​ Parastolsis ​ Movement where food is broeken down in digestive tract ○​ Segmentation ​ Term for the mouth ○​ Buccal ​ Oral cavity performs all except ○​ Absorption of nutrients ​ Specific tissue type is epithilum of oral mucosa ○​ Straifed squamous ​ Hard and soft pallet make up ○​ Roof ​ Tounge makes up ○​ Floor ​ Cheeks are made up of ○​ Buccal muscles and fat pads ​ From lips to nose ○​ Philtrum ​ Term desicbes space between cheeks and teeth ○​ Vestibule ​ What term describes the opening between soft palate and tongue ○​ Fauces ​ Structure that hangs from soft pallet keeps food from the nose ○​ Uvula ​ Term describes the gums ○​ Gengiva ​ Which pahringial arch is anterior ○​ Palatoglossal ​ Posteior arch ○​ Palatopharyngeal ​ Inbetween bprh arches ○​ Palatine tonsils ​ Primary functions of the tongue ○​ Mechanical, manipulating food, sensory analysis, secretion of mucins ​ Body of the tongue is also called ○​ oral portion ​ Root ○​ pharyngeal portion ​ Projections of mucosa on the tongue that have taste buds ○​ Lingual papillae on dorsum ​ Thin fold of musocus membrane connecting body of tongue to floor of the mouth ○​ Lingual frinulum ​ Call the folds underneath the tongues ○​ Plica fimbriata ​ Vein underneath the tongue that absorbs tongue ○​ The lingual vein ​ Term descibres insertion and origin in the tongue ○​ Intrinsic ​ Term describes only one (origin or insertion) on tongue ○​ Extrinsic ​ Gross movent of the tongue ○​ Extrinsic ​ Fine movements of the tongue ○​ Intrinsic ​ What cranial never is reespoible for intrinsic and exterinsic movement of the tongue ○​ CN XII hypoglossal ​ Part of tooth is superior to ○​ Crown ​ Part of tooth at the boundary of teh gum ○​ Neck ​ Part of tooth under gum ○​ Root ​ Space inside the tooth ○​ Pulp cavity ​ Shows where gums are relative to the tooth ○​ Gingival sulcus ​ Official term for chewing ○​ Mstication ​ Dental tissue fills pulp cavity ○​ Pulp ​ What delta tissue makes up the majority of the tooth ○​ Dentin ​ What spacial tissue is around the root ○​ Cementum ​ What special tissue cover the crown of the tooth ○​ Enamel (hardest material in the body) ​ Harvest and least reactive material​ ○​ enamel ​ Baby/disiduse teeth ○​ 20 ​ Kept teeth ○​ 32 ​ Adult have if they did not have wisdom teeth ○​ 28 ​ How do we label primary teeth ○​ Name or capital letter ​ Name adult teeth ○​ Name or Arabic numeral ​ Appropriate dental formula for a child ○​ Missing 2 pre moral and 2 3rd molars ○​ 2,2,2,0,2,2,0 ​ Adult dental formula ○​ 2,2,2,4,2,2,2 ​ If a person had a dental formula of 1234567 how many ○​ Central incisors ​ 1 ○​ Lateral incisor ​ 2 ○​ Canines ​ 3 ○​ Premolars ​ 4 ○​ 1st molars ​ 5 ○​ 2nd molars ​ 6 ○​ 3rd molars ​ 7 ​ What class of antibodies can be found in saliva ○​ Antibody A ​ Digestive enzymes can be found in saliva ○​ TRUE (amalayes and lipase) ​ Each salivary gland is inervated as.. ○​ Dual inervated ​ Anatomical name for the throat ○​ phayrnx ​ Region of phaynx is not used bty digestive ○​ Nasopharynx ​ The specific tissue type is pharyngeal mucosa ○​ Stratified squamous epithelium ​ Stratified squamous to the bottom of the.. ○​ Espogus and the simple columnar epithelium ​ Which part of digestive tract is the first not shared with other systems ○​ Esophagus ​ Espogus is — to the trachea and heart ○​ Posterior ​ The esophagus enters the abdomen via what structure ○​ Esophageal hiatus ​ The esophagus begins anterior to which vertebrae ○​ C6 ​ The muscularis pn the top 1/3 of esophagus ○​ skeletal muscle only ​ Middle third of the esophagus ○​ Both ​ Bottom of the esophagus ○​ Smooth muscle ​ What sphincter stops air from entering esophagus ○​ UES ​ Bottom sphincter ○​ LES (cardiac sphincter) ​ Sphincter that goes to the small intestine ○​ Pyloric sphincter ​ What is the term for swallowing ○​ Degulttion ​ Swallowing is voluntary and once enters the esophagus it is ○​ Involuntary ​ Part of the brain controls the swallowing reflex ○​ Medulla ​ Which cranial nerve is involved in the swallowing reflex ○​ Trigeminal and glassophyrngeal ​ Which abdominopelvic region is the stomach in ○​ Upper left ​ Call the mixture of food with stomach secretions ○​ Chyme ​ Which is not a major function of the stomach ○​ Absorb materials ​ What name is the medial surface of the stomach ○​ Lesser curvature of the ​ Lateral surface of the stomach ○​ Greater curvature ​ Stomach region ithe s closest to the esophagus ○​ cardia/cardiac region ​ Which part/region of the stomach connects to the small intestine ○​ pyloris/pyloric region ​ Portion of the stomach that comes above the cardia/where esophagus comes in ○​ Fundus ​ Biggest part of the stomach ○​ Body ​ What call the folds of mucousa inthe stomach to let it expand ○​ Ruggae ​ The stomach has 3 layers of smooth muscle ○​ True (oblique layer) ​ Specific tissue type of gastric mucosa/stomach ○​ Simple columnar epithelium ​ Call the indentions of the mucosa that hae the gastric glands ○​ Gastric pits ​ Which cell type in the stomach secrets intrinsic factor and HCL ○​ Parietal cells ​ Chief cells ○​ Pepsinin (breaks down proteins) ​ Endocrine cells in the stomach secrete to help break down food ○​ TRUE ​ Which portion of small intestine connects to the stomach ○​ Duodenum ​ Which portion of the small intestine is where most digestion occurs ○​ Jejunum ​ Last 12 feet of the small intestine ○​ Illium (not much absoprion here) ​ Circular folds in the mucosa of the small intestine ○​ Plica circulars ​ Finger-like projections on mucosa ○​ Villi ​ Microvilli at the apical end of the villi ○​ Brush border ​ Each intestinal villi has what inside of it ○​ Neves ○​ Capillaries ○​ Lactials ​ Call the initial glands at the base of the initial villi ○​ Intestinal crypts ​ What cell type in the intestinal crypts produces new cells to cover the villi and are constantly shed ○​ Stim cells ​ What cells produce antimicrobial cells ○​ Paneth cells ​ Menteric reflex ○​ a reflex action in the intestines that causes the digestive tract to contract and relax in a wave-like motion ○​ In muscularis ​ Interigastic reflex ○​ When pH in the intestine is too low it shuts down the pyloric sphincter ​ Where is the pancreas located ○​ Posterior to the stomach ​ Portion of the intestine is the pancreas associated with(where does it dump its stuff)  ○​ Duodenum ​ Call the exocrine structures of the pancreas ○​ Asceni ​ Is the majority of the pancreas exocrine or endocrine glands ○​ Exocrine ​ What hormone stimulates the pancreas to release the buffers to neutralize the stomach acids ○​ Secretin ​ CCK function ○​ Release of digestive enzymes ​ Largest visceral organ in the body ○​ Liver ​ Liver ○​ 2 lobes (right and left) (right is larger and made of quadrate and caudate) ​ Gallbladder ○​ In fossa on the liver ○​ Bile storage and concetration ​ Bile ○​ Release to help break down fats ○​ Without causes lipids to clump and become harder to digest ​ Cells in liver ○​ Hepatacyes ​ Lobules are what shape and contain ○​ Hexagon with blood and bile ○​ Carry blood to a central cavity ​ Phagocytes in liver ○​ Eat up stellate macrophages ​ Hepatic ducts come to ○​ Common bile duct to cyst bile duct ○​ Joins at ampulla ​ Carbs and amnio acids absorbed by ○​ Cotransport ​ Fats ○​ Direct diffusion ​ Illeosecal valve ○​ Between small and large intestine ​ Large intestine ○​ Ascending, transverse, descending, sigmoid ​ Capillaries in anal region ○​ Hermroid plexus Review structures of the liver, small intestine, large intestine, gallbladder