Upper GI Anatomy - Lecture slides.pptx

Upper Gastrointestinal tract- Gross and Dr Anthony Adefolaju Microanatomy...

Upper Gastrointestinal tract- Gross and Dr Anthony Adefolaju Microanatomy Lecturer, Anatomy [email protected] UM1010 - GI Block Where opportunity creates success Macro Learning Outcomes Describe the functional anatomy of the digestive tract (oral M1.I.GAS.AN cavity, oesophagus, stomach, duodenum, jejunum, ileum, A1 caecum and colon), accessory digestive organs (salivary glands, liver, gallbladder, pancreas) and the spleen. M1.I.GAS.AN Outline the major structures of the neurovascular supply to A2 the gastrointestinal system. Describe the organisation and clinical significance of the M1.I.GAS.AN parietal and visceral peritoneum, the greater and lesser sacs, A3 mesenteries and peritoneal ‘ligaments’. M1.I.GAS.AN Understand specific common clinical examples associated A4 with the gastrointestinal system. 1. Functional anatomy of the oral region, oesophagus, stomach and duodenum. 2. Functional anatomy of the pancreas, What we will liver and gall bladder cover in this session 3. Their neurovascular supply 4. Upper GI, hepatic and pancreatic histology. Introduct ion The digestive tract and associated organs. Oral Region oral cavity Teeth gingivae Tongue palate and the region of the palatine tonsils   The oral cavity is divided into two parts: 1. The vestibule Oral cavity proper- Boundaries of the oral cavity Tongue – Overview of structure Nerves of the oral cavity  Salivary 1. glands The salivary glands are the parotid, submandibular, and sub lingual glands. 2. Saliva is the clear, tasteless, odourless viscid fluid, secreted by these glands and the mucous glands of the oral cavity 3. Can you mention the functions of saliva?  Pharynx  a musculofascial (Skeletal ms.) half- cylinder that connects the oral and nasal cavities in the head to the larynx and oesophagus in the neck.  Through the pharynx, food bolus moves from the mouth to the oesophagus and stomach in a complex three-stage process known as deglutition (swallowing). Oesopha gus Extends from C6 to T11 20-40cm long & 2cm wide Relations and constrictions (ABCD) Sphincters; Upper (anatomical) and Lower (physiological) Oesopha gus Muscular (skeletal Muscle layers and smooth) tube - Outer longitudinal Muscle layers - Inner circular Muscular tube (skeletal and smooth muscle) - Upper 3rd – skeletal muscle - Middle 3rd – a mixture of skeletal and smooth muscle fibres. - Lower 3rd – Smooth muscle Oesopha gusInternal feature s Histolo gy Epithelium? Muscle layers Abdominal quadrants and regions  Derivatives of the gut Regions of the GI tract derived from the primitive fore, mid, hindgut. Stomach In Locatio relation to abdo regions & n peritoneu m? Shape Parts Relations Peritoneum and Peritoneal Cavity Stomach Parts Internal features Histology Stomach Parts Internal features Histology Gastric epithelium - simple columnar The epithelium forms gastric pits and gastric glands. The gastric pits have mucous cells that produce mucous to protect the inner lining of the stomach. The gastric glands are lined by ( Parietal cells - HCl ), (Chief cells - pepsinogen and chymosin), (Enteroendocrine cells – local hormones) Duodenum Locatio In relation to abdo regions & n peritoneum? Shape Parts Relations Retro peritoneal. C-shaped and has four parts.  Duodenum Parts Internal features Histolog y Superior (1st) part - no circular folds Other parts of the duodenum have circular folds (plicæ circulares, valves of Kerkring) and these are large valvular flaps projecting into the lumen. Unlike gastric rugae, do not disappear when the intestine is distended. The circular folds slow the passage of food along the small intestines.  Pancreas Locatio In relation to abdo regions & n peritoneum? Shape Parts Relations It is retroperitoneal except at the tail. It has exocrine and endocrine functions  Pancreas Parts Why accessory duct? Internal features Histology Exocrine pancreas - Produce digestive enzymes Endocrine pancreas - Produce hormones (Glucagon, insulin and somatostatin)  Liver Location Relations Surfaces Anatomical vs Functional lobes Posterior-inferior view of the liver Lobes of the Liver The liver consists of 2 main lobes –Right and Left. Intraperitoneal Additional lobes from the right are caudate and Ligaments of the Liver quadrate lobes Falciform ligament Coronary ligament (anterior and posterior folds) Visceral Surface Triangular ligaments (left and right) Impressions of other organs Lesser omentum  Liver – Blood supply Dual blood supply: Hepatic artery & vein proper (25%) oxygenation Hepatic portal vein (75%) main blood supply to the liver conveying absorbed nutrients from the small and large bowel. Histology of the Liver Polygonal hepatic lobules which form the basic functional units of the organ. Periphery of the hexagon has three structures known as the portal triad. The direction of bile flow is opposite to blood. Bile canaliculi are the smallest branches of the biliary tree. Stellate macrophages, called Kupffer cells…. Phagocytose aged erythrocytes.  Biliary Ducts and Gallbladder Extrahepatic bile passages and pancreatic ducts. 1. Sphincter of bile duct 2. Sphincter of pancreatic duct 3. Hepatopancreatic sphincter The Gall Bladder is an intraperitoneal pear-shaped sac Location - fossa between the inferior aspects of the right and quadrate lobes of the liver. Storage capacity - 30-50ml. Three parts: Fundus, Body and Neck Spleen Location Surfaces Relation s Internal features Has a diaphragmatic surface and a visceral surface. Old red blood cells are recycled in the spleen, and platelets and white blood cells are stored there.  Derivatives of the gut and blood supply Regions of the GI tract derived from the primitive fore, mid, hindgut. Blood Supply - Abdominal viscera Blood Supply - Coeliac trunk branches Coeliac trunk  Common hepatic artery Hepatic art. proper Right gastric artery Gastroduodenal artery Right gastro-omental  Left gastric artery  Splenic artery Left gastro-omental Short gastric arteries Dorsal pancreatic artery Inferior pancreatic  Nerve supply Innervat ion Foregut receives innervation from the autonomic nervous system: Parasympathetic innervation - Vagus nerve. Sympathetic supply - T5-T9 spinal cord segments 1. Functional anatomy of the oral region, oesophagus, stomach and duodenum. 2. Functional anatomy of the pancreas, What we liver and gall bladder covered in this session 3. Their neurovascular supply 4. Upper GI, hepatic and pancreatic histology. Additional resources Gray's anatomy for students https://uclan.alma.exlibrisgroup.com/leganto/public/44UOCL_INST/citation/55864838200 03821?auth=SAML Abrahams' and McMinn's clinical atlas of human anatomy https://uclan.alma.exlibrisgroup.com/leganto/public/44UOCL_INST/citation/55865199800 03821?auth=SAML Complete Anatomy https://uclan.alma.exlibrisgroup.com/leganto/public/44UOCL_INST/citation/55865371200 03821?auth=SAML Wheater's functional histology : a text and colour atlas https://uclan.alma.exlibrisgroup.com/leganto/public/44UOCL_INST/citation/55866190800 Macro Learning Outcomes Describe the functional anatomy of the digestive tract (oral M1.I.GAS.AN cavity, oesophagus, stomach, duodenum, jejunum, ileum, A1 caecum and colon), accessory digestive organs (salivary glands, liver, gallbladder, pancreas) and the spleen. M1.I.GAS.AN Outline the major structures of the neurovascular supply to A2 the gastrointestinal system. Describe the organisation and clinical significance of the M1.I.GAS.AN parietal and visceral peritoneum, the greater and lesser sacs, A3 mesenteries and peritoneal ‘ligaments’. M1.I.GAS.AN Understand specific common clinical examples associated A4 with the gastrointestinal system.