Digestive System PDF

Digestive system 3. Tunica muscularis composed of organs whose primary - usually 2 layers of smooth function are ingestion, digestion, and muscles, inner circular and outer absorption of food and excretion of longitudinal muscle layer...

Digestive system 3. Tunica muscularis composed of organs whose primary - usually 2 layers of smooth function are ingestion, digestion, and muscles, inner circular and outer absorption of food and excretion of longitudinal muscle layer undigested food - stomach has 3 layers of tunica muscularis, inner oblique, it include the mouth, pharynx, middle circular and outer esophagus, stomach, small and large longitudinal muscle layer intestine and the accessory digestive organs (salivary glands, liver, pancreas 4. Tunica serosa and gallbladder) - Visceral peritoneum - it is a single layer of simple Wall of Digestive tract squamous epithelium which secretes a small amount of 1. Tunica mucosa serous lubricating fluid which - functions : absorption, secretory reduces friction among the G.I. and protection tract organs and the body wall. Tunica mucosa composed of three MAIN DIVISIONS OF THE G.I TRACT sublayers Digestive tract Oral cavity a. epithelium - lined by a simple Pharynx ( oropharynx and columnar except mouth, laryngopharynx) pharynx, esophagus, and lower Esophagus anus which are lined by Stomach stratified squamous non keratinized Small Intestines duodenum b. lamina propria - loose areolar jejunum tissue ileum c. muscularis mucosa - made up Large intestines of smooth muscle cecum with vermiform appendix 2. Submucosa Ascending colon - Connective tissue consisting of Transverse colon the ff: blood vessels, lymphatics, Descending colon and nerves Sigmoid colon - major function: nutritive and Rectum protective Anus/Anal Canal ACCESSORY GLANDS/ORGANS 2 INCISORS - Lips 2 CANINES - Teeth 2 MOLARS - Tongue - Salivary Glands: Deciduous teeth erupt on the average 1. Big between 6 and 24 months after birth Parotid and are usually shed between the ages Submandibular of 6 and 12 Sublingual there are 32 permanent teeth in a full 2. Small set, 8 in each quadrant: Lingual Labial 2 incisors, 1 canine, 2 premolars, and Buccal 3 molars - eruption of the third molars/wisdom Liver teeth, is delayed until after the age of Pancreas 18 Gallbladder Tongue For speech and mechanical MOUTH digestion of food Oral vestibule Papillae: space between the lips and the a. vallate teeth - Largest and found at the sulcus terminalis that divides the Oral Cavity Proper tongue in to anterior ⅔ and inside the mouth, the roof of posterior 1/3 the mouth is the hard palate b. foliate and the floor of the mouth is c. fungiform the tongue d. Filiform - this papillae doesn't have taste buds TEETH - taste buds: sensory organs of taste especially numerous around vallate Types of teeth: papillae Deciduous/Temporary ( Milk tooth ) Permanent teeth The deciduous set consists of 20 teeth, 5 in each quadrant Nerves of tongue: 1. General sensory Viral inflammations: - lingual (CN V) (anterior 2/3 of tongue) Mumps / parotitis - Glossopharyngeal (CN IX post. 1/3 of - Mumps is a contagious the tongue) disease caused by a virus. - Vagus (CN X) epiglottic area It is a painful swelling in your parotid salivary 2. Special sensory glands (parotitis) - anterior 2/3 - chorda tympani from VII (facial) Important structure - posterior 1/3 - glossopharyngeal (CN embedded: facial nerve IX) 2. Submandibular gland 3. Motor - Second largest - to intrinsic and extrinsic muscles of - Mixed serous and mucous gland tongue - hypoglossal but more of serous - Duct : wharton’s - which opens at sublingual Salivary Glands papillae - secretion of saliva (salivary amylase) poured in the oral cavity 3. Sublingual gland starts digestion of carbohydrates. - Smallest of 3 Salivary glands - Mixed serous and mucous Types of Salivary Glands: but more mucous 1. Parotid Gland Ducts: - largest, lies on the posterior border of Rivinu’s - small ; opens at ramus of mandible summit of sublingual fold - secretion is purely serous Bartholin’s - Large; - duct : stensen's - opens into the opens into sublingual vestibule of mouth opposite second papillae molar tooth and will drain in the upper 2nd molar tooth Stensen's duct, also known as the parotid duct, is a tube that carries saliva from the parotid gland to the mouth PHARYNX 5. Cardiac region - are surrounding the point of entry of food 3 parts of the pharynx 1. Nasopharynx or epipharynx - Located behind the nasal cavity 2. Oropharynx or mesopharynx - Located behind the oral cavity - Palatine tonsil bounded by palatoglossal and palatopharyngeal fold 3. Laryngopharynx - Located behind the larynx - Continuous with the esophagus Esophagus A muscular tube extending from the pharynx to the stomach With 3 anatomical constrictions: Rugae - Fold of mucosa/Folds of the 1. At the stomach pharyngo-esophageal junction - 2. When left main bronchus crosses esophagus 3. When it enters the diaphragm Stomach Located within the peritoneal cavity With greater and lesser Cells in the stomach curvatures 1. Parietal cells - Secretes HCl Parts of the stomach: (hydrochloric acid) and 1. Fundus - found on the left intrinsic factor that for the border absorption of the Vitamin 2. body B12 which is important in 3. Pyloric antrum the maturation of the 4. Pylorus - tubular portion  blood cells, if you dont pancreatic duct draining have intrinsic factor this to the second part of the will lead to pernicious duodenum anemia - GROSS STRUCTURAL 2. Chief cell - secretes pepsinogen that will be converted to pepsin Characteristics: upon exposure to HCl - major duodenal papilla 3. Mucus neck cell secretes mucus - with sphincter of oddi around 4. G cells - secretes gastrin - common duct and main pancreatic duct of wirsung Swallowing minor duodenal of The tongue will move upward accessory pancreatic and backward to push the food duct, duct of santorini bolus. As the food moves downward, the soft palate rises, Jejunum sealing off the nasopharynx, located at the left upper while the epiglottis lowers to quadrant close the larynx. The food then upper ⅖ and 8ft long passes through the oropharynx, thicker than the ileum laryngopharynx, and into the esophagus. Ileum Chyme - food plus acid in the longest, found at the right lower stomach. quadrant ⅗ and 12ft long Small intestines has peyer’s patches or Longest aggregated lymphoid nodules 20ft (bilog bilog na continous absorbs nutrients that’s why it nodules) has villi/microvilli and plica circularis (to increase the area of Large intestines absorption of the small - 5 ft. long intestine) Parts of the Large intestine: duodenum cecum - widest part of the large - C-shaped intestine - With 4 parts (superior, vermiform appendix - located descending transverse posteromedial to cecum and ascending) Ascending colon - The common bile duct Transverse colon and the main pancreatic Descending colon duct and the accessory Sigmoid colon - S-shaped  Rectum - continuation of Celiac trunk sigmoid at S3 vertebra superior mesenteric artery Anal canal inferior mesenteric artery Characteristics of the Large intestine: Accessory Digestive Organs plica semilunaris - folds of the Salivary Glands Large intestines - Parotid gland - purely Haustra/sacculations - the serous, with stensen’s circular/round part of the folds duct that opens into the of the large intestine oral vestibule opposite Taenia coli - bond of the upper 2nd molar longitudinal muscle (tae nia coli tooth (kulay) white ) - Submandibular gland - Epiploicae appendices - fatty mixed, it’s duct wharton’s tags / yellow tags open into sublingual papilla (mostly serous) - Sublingual gland - it has 2 ducts : (mostly mucus) Bartholin’s duct - open into sublingual papilla Duct of rivinus - opens into sublingual fold Liver Largest gland of the body Internal anal sphincter with right and left lobe this sends a signal to the brain, Filters the blood and secretes the brain will know if you will bile excrete gas/feces - 2 smaller lobes: Involuntary quadrate lobe caudate lobe External anal sphincter Livers Ligaments: Voluntary Falciform ligament - divides the we can contract it when we liver in right and left lobes have bowel movements Coronary ligaments - top part of the liver Triangular ligaments - top part of the liver Blood Supply of the G.I.T Inferior/Visceral surface  Fissure for ligamentum teres Common hepatic duct hepatis, ligamentum venosum - Formed by the joined Fossa of gallbladder and IVC right and left hepatic Porta hepatis duct a. common bile duct Cystic duct b. hepatic artery - duct of gallbladder c. portal vein Common bile duct Lymphatic nerves - formed by the union of cystic duct and common Gallbladder hepatic duct Located under the surface of the - plus the main pancreatic liver duct that will form the stores and concentrates bile ampulla of vater that will parts: fundus, body, neck, drain to the major infundibulum duodenal papilla and will mucosa, muscular layer and drain at the sphincter of serosa oddi. spiral valve of heister Pancreas retroperitoneal organ located at the back of the stomach both endocrine(enzymes) and exocrine organs (islet of langerhans that releases hormones) with head, neck, body, tail, and uncinate process 2 major ducts : - Major duct of wirsung - accessory duct of santorini then will drain to the duodenum and will be joined by the common bile duct. Extrahepatic biliary tract