PT102 Other Organ Systems 1 GI PDF

PT102 OTHER ORGAN SYSTEMS 1 PREPARED BY: JOHN PATRICK R. LENTEJAS, PTRP, MSc SEPTEMBER 30, 2024 This is the PPT for PT102 Other Organ Systems 1 module prepared by Asst...

PT102 OTHER ORGAN SYSTEMS 1 PREPARED BY: JOHN PATRICK R. LENTEJAS, PTRP, MSc SEPTEMBER 30, 2024 This is the PPT for PT102 Other Organ Systems 1 module prepared by Asst Prof JPRL for students registered in PT102 Semester 1 Academic Year 2024–2025. Obtain written permission prior to using this document for any other purpose. Copyright belongs to the College of Allied Medical Professions, University of the Philippines Manila. All rights reserved 2024. DIGESTIVE SYSTEM  LEARNING OBJECTIVES At the end of the session, the students should be able to: Explain the function and processes of the digestive system Describe the structure and function of the layers of digestive canal Identify the location and function of the structures found in the oral cavity Discuss functional anatomy of the tongue, pharynx, esophagus, stomach, and their innervation and blood supply Identify the location and function of the salivary glands Discuss the different stages of swallowing reflex Identify the organs located on each abdominal quadrant or region Differentiate the regions of small and large intestine in terms of histological specialization, segmental movements, and function Discuss the location, function, and histological specialization of the different accessory glands Trace the pathway of bile and pancreatic juices from their respective organs to the duodenum Trace the pathway of blood from the liver to the general circulation FUNCTION OF DIGESTIVE SYSTEM INGESTION – taking food into mouth SECRETION – release of water, acid, buffers, enzymes into lumen of digestive canal MIXING AND PROPULSION – churning and movement of food through digestive canal DIGESTION – mechanical and chemical breakdown of food ABSORPTION - passage of digested products from digestive canal into blood plasma and lymph plasma DEFACATION – elimination of feces from digestive canal  LAYERS OF DIGESTIVE CANAL From deep to superficial; present from stomach to intestines MUCOSA Inner lining, mucous membrane Consist of epithelial layer (secretion and absorption) Lamina propria – areolar CT, contain blood and lympathics for nutrient absorption Muscular mucosae – creates folds to increase surface area for digestion SUBMUCOSA Areolar CT, binding mucosa to muscularis Blood and lymphatic vessels, MALT – immune function Submucosal Plexus (Meissner’s plexus) – controls secretion and blood flow MUSCULAR LAYER (Muscularis Externa) Inner circular layer – decrease diameter of lumen Outer Longitudinal layer – shortens tube Myernteric Plexus (Auerbach’s plexus)– controls and coordinates motor activity of muscle layer SEROSA Outer covering, continuation of peritoneal membrane ORAL CAVITY ORAL CAVITY Roof: Hard palate (palatine process of the maxilla and the palatine bone) and soft palate (aponeurosis of tensor palati muscle) FUNCTION OF SOFT PALATE (palatine muscle): Separates the nasal and buccal cavities In speaking, swallowing and blowing, the soft palate closes off the nasopharynx from the buccal cavity Uvula – finger shaped located center of the posterior margin of soft palate FUNCTION: PREVENT FOOR FROM ENTERING PHARYNX PREMATURELY Pharyngeal arches Palatoglossal Arches: lie between soft palate and base of tongue Palatopharyngeal Arches: lie between soft palate and side of the pharynx Palatine tonsil: lie between palatoglossal and palatopharyngeal arches Fauces: entrance to the oropharynx Floor: tongue and mylohyoid muscles Laterally: cheeks (buccal region) – buccinator muscle, zygomatic bone and zygomatic arch  Oral Cavity Oral Vestibule narrow space between the lips and cheeks, and the gums and teeth This material was prepared by Mary Rose C. Gonzales for OTPT 102 students of the College of Allied Medical Professions, UP Manila. July 2010. Edited by CVIsaac July 2011. Please obtain permission before use. TONGUE FLOOR OF THE ORAL CAVITY FUNCTION: (1) Assist in chewing and swallowing (2) Sensory (3) Taste receptors (4) Mechanical processing important for speech Innervation: Anterior 2/3 general sensation – lingual branch CN V (Trigeminal Nerve) Anterior (taste) – chorda tympani of CN VII (Facial Nerve) Posterior 2/3 both taste and sensation – glossopharyngeal nerve MOTOR – CN XII (hypoglossal nerve) Blood Supply: lingual branch of the external carotid artery  SALIVARY GLANDS PAROTID GLAND Largest, below external auditory meatus and behind ramus of mandible, anterior of SCM. Produces more water secretion of enzymes Nerve: Parasympathetic - glossopharyngeal SUBLINGUAL GLAND Beneath the tongue, superior to submandibular glands; produces mucus rich saliva SUBMANDIBULAR GLAND Floor of oral cavity; produces mixed (mucus & enzymes) Nerve (both submandibular and sublingual) parasympathetic, facial nerve SALIVA – lubrication Salivary amylase – initial digestion of starch 99.5% water, 0.5% solutes – Na+, K+, Bicarbonate, chloride, phosphate Lysozyme – bacteriolytic enzyme *** Formation of bolus Pharynx Musculofascial tube, incomplete anteriorly Area behind the nasal and oral cavities and the larynx Funnel shaped space ending at the level of the 6th cervical vertebra Acts as a common entrance to the respiratory and alimentary tracts Pharynx Arterial supply: superior thyroid and ascending pharyngeal branches of the external carotid Innervated by: CN IX (glossopharyngeal) - sensory CN X (vagus) – motor Nasopharynx* - sensory from maxillary division of CN V Pharynx a. Nasopharynx Communicates anteriorly with the nasal cavities through the posterior nares, and lies above soft palate Location of the opening of the Pharyngo-tympanic or Eustachian tubes Prevents regurgitation of food through the nose b. Oropharynx Lies behind mouth and tongue; Segment between the palate (uvula) above and the hyoid bone (tip of epiglottis below) c. Laryngopharynx Narrowest part of the pharynx, lies behind the larynx From the tip of the epiglottis to the termination of the pharynx in the esophagus at the level of C6 This material was prepared by Mary Rose C. Gonzales for OTPT 102 students of the College of Allied Medical Professions, UP Manila. July 2010. Edited by CVIsaac July 2011. Please obtain permission before use. Describe the position of the esophagus from the larynx Esophagus Starts from cricoid cartilage (at vertebral level C6) and ends at the gastroesophageal (GE) junction pierces the diaphragm through the esophageal hiatus (at vertebral level T10) upper 5% of the esophagus consists of skeletal muscle only; middle 45% of the esophagus consists of both skeletal muscle and smooth muscle interwoven together; and the distal 50% of the esophagus consists of smooth muscle only FUNCTION: propels the swallowed food into the stomach  Anteriorly – trachea, arch of the aorta, the left bronchus and the left atrium Posteriorly – 6th and 7th cervical vertebrae, thoracic vertebrae Blood supply: inferior thyroid artery, branches of the descending thoracic aorta and the left gastric artery; inferior thyroid veins and azygos vein Innervation: Somatic – C1 and hypoglossal nerve (upper part only); vagus and sympathetic trunks via the esophageal plexus Esophagus Composed of two sphincters: FUNCTION: prevent air from entering the upper esophagus and gastric acid from entering the lower esophagus Upper Esophageal Sphincter (UES) - skeletal muscle (Voluntary control) that separates the pharynx from the esophagus Opening muscles (i.e., thyrohyoid and geniohyoid muscles) and closing muscles (i.e., inferior pharyngeal constrictor and cricopharyngeus) Lower Esophageal Sphincter (LES) - smooth muscle (Involuntary control) that separates the esophagus from the stomach The LES prevents GE reflux.  As part of the swallowing reflex, the upper esophageal sphincter relaxes to permit swallowed food to enter the esophagus. The upper esophageal sphincter then contracts so that food will not reflux into the pharynx. A primary peristaltic contraction creates an area of high pressure behind the food bolus. The peristaltic contraction moves down the esophagus and propels the food bolus along. Gravity only accelerates the movement. (NOTE: The reason why swallowing persists despite a person being upside-down) A secondary peristaltic contraction clears the esophagus of any remaining food. As the food bolus approaches the lower end of the esophagus, the lower esophageal sphincter relaxes.  Esophagus Gastro-esophageal Junction 50° angulation to the left that prevents regurgitation together with the lower esophageal sphincter Act as valve This material was prepared by Mary Rose C. Gonzales for OTPT 102 students of the College of Allied Medical Professions, UP Manila. July 2010. Edited by CVIsaac July 2011. Please obtain permission before use. Swallowing Reflex (Deglutition) Sensory Input: CN IX glossopharyngeal Swallowing Center in Medulla Oblongata Output: Somatic neurons of pharyngeal muscles and upper esophagus, and autonomic (lower esophagus)  VOLUNTARY STAGE PHARYNGEAL STAGE ESOPHAGEAL STAGE Abdominal Quadrants  Abdominal Regions and Quadrants Abdominal regions divide the abdomen into nine regions  STOMACH FUNCTION: bulk storage of ingested food, mechanical breakdown of ingested food Chemical digestion: gastric juices containing HCI (kills bacteria and denatures proteins), pepsin (begins the digestion of proteins), intrinsic factor (aids absorption of vitamin B12), and gastric lipase (aids digestion of triglycerides) *** FORMATION OF CHYME (soupy, strongly acidic mixture) Functional Movement: mixing Blood supply: Left gastric a. – supply lesser curvature and cardia Splenic a. – supply fundus and greater curvature Common hepatic a. – lesser and greater curvature (via right gastric, right gastroepiploic and gastroduodenal a.) Innervation: Vagal fibers, Enteric Nervous System (myenteric plexus)  STOMACH Intraperitoneal, J-shaped, between T7 and L3 vertebrae, variable in size, and projects to the left 4 Regions: Cardia – the superior orifice; junction between stomach and esophagus (close proximity to heart) Fundus – superior to gastroesophageal junction, contacts the diaphragm Body – both fundus and proximal body receive the ingested meal (orad region) Pylorus – inferior orifice; distal part of the stomach Pyloric Antrum – wide part, together with distal body start point of contraction – mix food and propel into the duodenum Pyloric canal – narrow part, connects to duodenum Pyloric sphincter – prevents reflux of duodenal contents into stomach 2 Curvatures: short lesser curvature, and long greater curvature Rugae – prominent longitudinal folds inside the stomach, permits expansion of gastric lumen Has extraoblique muscle layer – for mixing and churning  SHORT INTESTINES Occupies all abdominal regions (except left hypochondriac and epigastric regions) Averages 6 m (20 ft) in length (range, 5.0–8.3 m [5– 25 ft]) and has a diameter ranging from 4 cm (1.6 in.) at the stomach to about 2.5 cm (1 in.) at the junction with the large intestine FUNCTION: primary role in the digestion and absorption of nutrients (90% OF NUTRIENT ABSORPTION), the rest occurs in the proximal portion of large intestine 3 subdivisions: Duodenum Jejunum Ileum Intestinal villi – series of fingerlike projections in the mucosa of small intestine Microvilli – “brush border” covers the epithelial cells BOTH improve total absorption area from 0.33m2 to 200m2 Functional movement: segmentation – back and forth movement to mix intestinal content  Duodenum First, widest, shortest and most fixed segment of the small intestines curves in a C around the head of the pancreas; also overlapped by the liver and gallbladder “mixing bowl” that receives chyme from the stomach and digestive secretions from the pancreas and liver receives the common bile duct and main pancreatic duct on its posterior/medial wall at the hepatopancreatic ampulla (ampulla of Vater) Blood Supply: Superior Mesenteric Artery Duodenum Gall bladder (cystic duct) + liver (common hepatic duct) – common bile duct Common bile duct from the liver and gallbladder and the pancreatic duct (duct of Wirsung) from the pancreas come together at a muscular chamber called the duodenal ampulla (ampulla of Vater) Duodenal papilla – opening where the ampulla of Vater is connected, closed by sphincter of Oddi Jejunum Duodenojejunal flexure Marks the boundary between the duodenum and the jejunum At this junction the small intestine reenters the peritoneal cavity, becoming intraperitoneal and supported by a sheet of mesentery. The jejunum is about 2.5 m (8 ft) long. The bulk of chemical digestion and nutrient absorption occurs in the jejunum Ileum Intraperitoneal Third and last segment of the small intestine, longest, averaging 3.5 m (12 ft) in length *Site of Vitamin B12 absorption Ileocecal valve – ending of ileum, controls the flow of materials from the ileum into the cecum of the large intestine Gastroileac reflex: The presence of food in the stomach triggers increased peristalsis in the ileum and relaxation of the ileocecal sphincter. As a result, the intestinal contents are delivered to the large intestine Lower Gastrointestinal Tract 1. Jejunum 2. Ileum 3. Colon This material was prepared by Mary Rose C. Gonzales for OTPT 102 students of the College of Allied Medical Professions, UP Manila. July 2010. Edited by CVIsaac July 2011. Please obtain permission before use.  LARGE INTESTINE Wider caliber compared to the small intestines Features: Taenia Coli: longitudinal muscular bands arising from the root of the appendix Haustration: sacculated appearance of the walls of the colon Blood Supply: Superior and Inferior mesenteric artery Functional/segmental movement: Haustral churning Mass movements – towards the rectum This material was prepared by Mary Rose C. Gonzales for OTPT 102 students of the College of Allied Medical Professions, UP Manila. July 2010. Edited by CVIsaac July 2011. Please obtain permission before use. LARGE INTESTINE FUNCTION: (1) the reabsorption of water and electrolytes, and compaction of the intestinal contents into feces; (2) the absorption of important vitamins produced by bacterial action; and (3) the storing of fecal material before defecation This material was prepared by Mary Rose C. Gonzales for OTPT 102 students of the College of Allied Medical Professions, UP Manila. July 2010. Edited by CVIsaac July 2011. Please obtain permission before use.  LARGE INTESTINE Divided into three parts: Cecum - first portion of the large intestine, which appears as a pouch Colon - the largest portion of the large intestine Rectum - the last 15 cm (6 in.) of the large intestine and the end of the digestive tract  Parts of the Large Intestine 1. Cecum Ileo-coecal junction: start of the large intestine at the right iliac fossa Vermiform Appendix: embryological remnant attached to the medial side of the base of the cecum This material was prepared by Mary Rose C. Gonzales for OTPT 102 students of the College of Allied Medical Professions, UP Manila. July 2010. Edited by CVIsaac July 2011. Please obtain permission before use.  Parts of the Large Intestine 2. Ascending, Transverse, Descending Part: Inverted U-shape towards the left iliac region 3. Sigmoid or Pelvic Colon descends into the pelvic cavity 4. Rectum starts at the level of the third sacral vertebra to the recto-anal junction Temporary storage of fecal material Anal canal – last portion of the rectum Internal anal sphincter – smooth muscle (involuntary) External anal sphincter –ring of skeletal muscle fibers (under voluntary control) This material was prepared by Mary Rose C. Gonzales for OTPT 102 students of the College of Allied Medical Professions, UP Manila. July 2010. Edited by CVIsaac July 2011. Please obtain permission before use. Parasympathetic Defecation Reflex Removes undigested feces from the body Stimuli: Distension of the rectal wall (S2- S4 cord level) Response: Smooth muscle of the internal anal sphincter relaxes (involuntary control), and peristaltic contractions in the rectum push material toward the anus External anal sphincter - under voluntary control, is consciously relaxed if the situation is appropriate for defecation Defecation is often aided by conscious abdominal contractions and forced expiratory movements against a closed glottis (the Valsalva maneuver) This material was prepared by Mary Rose C. Gonzales for OTPT 102 students of the College of Allied Medical Professions, UP Manila. July 2010. Edited by CVIsaac July 2011. Please obtain permission before use.  ABDOMINAL AORTA BRANCHES: Celiac Trunk is located at T12 vertebral level and supplies viscera that derive embryologically from the foregut (i.e., intra-abdominal portion of esophagus, stomach, upper part of duodenum, liver, gall bladder, and pancreas) a. Left gastric artery b. Splenic artery c. Common hepatic artery Superior Mesenteric Artery is located at L1 vertebral level and supplies viscera that derive embryologically from the midgut (i.e., lower part of duodenum, jejunum, ileum, cecum, appendix, ascending colon, and proximal two-thirds of transverse colon) Renal Arteries supply the kidneys Gonadal Arteries supply the testes or ovary Inferior Mesenteric Artery is located at L3 vertebral level and supplies viscera that derive embryologically from the hindgut (i.e., distal one- third of transverse colon, descending colon, sigmoid colon, and upper portion of rectum). Common Iliac Arteries are the terminal branches of the abdominal aorta.  Accessory Organs 1. Liver 2. Gall Bladder 3. Pancreas This material was prepared by Mary Rose C. Gonzales for OTPT 102 students of the College of Allied Medical Professions, UP Manila. July 2010. Edited by CVIsaac July 2011. Please obtain permission before use.  Liver Largest visceral organ, and has the greatest regenerative capacity Glisson’s Capsule: fibrous covering Falciform ligament – divides the liver into left and right parts The major segments of the liver are brought by the subdivisions by the hepatic artery, portal vein, and hepatic ducts – further divides the L and R lobes into 4 segments each (8 segments) Coronary ligament - supports the liver to the diaphragm Round ligament of liver (ligamentum teres) – found inferiorly of falciform ligament, remnant of left umbilical vein) This material was prepared by Mary Rose C. Gonzales for OTPT 102 students of the College of Allied Medical Professions, UP Manila. July 2010. Edited by CVIsaac July 2011. Please obtain permission before use.  Liver Lobules Liver lobules – basic functional units of the liver (hexagonal in cross sectional area) 6 portal areas/ hepatic triads on each corner of the lobule Portal area – has 3 structures: hepatic portal vein, hepatic artery proper, and bile duct > deliver blood to sinusoids of lobules > hepatocytes absorb and secrete materials into bloodstream > central vein > hepatic vein > Inferior vena cava Functions of Liver Metabolic regulation: All blood leaving the absorptive surfaces of GI enters hepatic portal system > liver Absorb nutrients and toxins, excess nutrients are stored, circulating wastes and toxins removed Absorption of fat-soluble vitamins (A,D,E,K) Largest blood reservoir Removal of old RBCs Synthesize plasma proteins for the blood Synthesis and secretion of bile  Hepatic Blood Supply Hepatic Artery Portal Vein Hepatic Artery Interlobular Branches for oxygen supply of the liver Intralobular Branches Hepatic Portal vein Central Veins formed by the splenic vein and Sublobular Veins superior mesenteric vein Hepatic Veins supplies nutrients and other Inferior Vena Cava chemicals absorbed from the intestine This material was prepared by Mary Rose C. Gonzales for OTPT 102 students of the College of Allied Medical Professions, UP Manila. July 2010. Edited by CVIsaac July 2011. Please obtain permission before use. Bile secretion and transport Bile – important for emulsification and digestion of lipids secreted by hepatic cells gathered by bile canaliculi > bile ductules > bile ducts> hepatic ducts > common hepatic duct Bile from common hepatic duct can flow to: Common bile duct which empties into the duodenum Enter cystic duct to the gall bladder This material was prepared by Mary Rose C. Gonzales for OTPT 102 students of the College of Allied Medical Professions, UP Manila. July 2010. Edited by CVIsaac July 2011. Please obtain permission before use.  Gall Bladder Stores and concentrates bile, until it is transported to the duodenum via common bile duct Attached to the fossa at the inferior surface of the liver Cystic duct: joins the Common hepatic duct to form the Common bile duct This material was prepared by Mary Rose C. Gonzales for OTPT 102 students of the College of Allied Medical Professions, UP Manila. July 2010. Edited by CVIsaac July 2011. Please obtain permission before use. Pancreas Lobulated, elongated gland at the epigastric region (lies posterior to the stomach), retroperitoneal organ n Parts: n Head: clasped by the C-shaped duodenum n Neck: where the portal vein and main pancreatic duct of Wirsung are formed n Body: main portion at the level of the 2nd and 3rd lumbar vertebra n Tail: extends to the left hypochondrium  Pancreas n Pancreatic acini – blind end of the pancreatic duct, n Secrete a mixture of water, ions, and pancreatic digestive enzymes into the duodenum (pancreatic juice) n Function: Delivers pancreatic juice into duodenum via pancreatic duct to assist absorption of lipids, carbohydrates, proteins n Pancreatic islet ( less than 1%) – scattered between acini n Endocrine gland (insulin and glucagon) This material was prepared by Mary Rose C. Gonzales for OTPT 102 students of the College of Allied Medical Professions, UP Manila. July 2010. Edited by CVIsaac July 2011. Please obtain permission before use.  SOURCES: Snell, R. S. (2012). Clinical anatomy by regions (9. ed., international ed). Lippincott Williams & Wilkins. Ellis, H. (2019). Clinical Anatomy Applied Anatomy for Students and Junior Doctors. : Wiley Blackwell. Dudek, Ronald W., Louis, Thomas, author., Fifth edition.. (2015). High-yield gross anatomy / Ronald W. Dudek, Thomas M. Louis. (5th). Jakarta: Wolters Kluwer Health. Martini, F., Tallitsch, R. B., & Nath, J. L. (2018). Human anatomy (Ninth edition). Pearson. Tortora, G. J., & Derrickson, B. (2017). Principles of anatomy & physiology. Fifteenth edition; Wiley Loose-Leaf Print Companion. Hoboken, New Jersey, John Wiley & Sons, Inc. Silverthorn, Dee Unglaub. (2019). Human Physiology: an Integrated Approach (8th ed.). New York: Pearson Education.