describe the four layers of the gi tract describe the four layers of the gi tract

It lines the lumen of the digestive tract. A few milliliters of watery fluid act as a lubricant to minimize friction between the serosal surfaces of the peritoneum. Thus, the location of these organs is described as retroperitoneal. Mucosa is the moist innermost layer; it lines the cavity of the organ. Within the mouth, the teeth and tongue begin mechanical digestion, whereas the salivary glands begin chemical digestion. The third layer of the alimentary canal is the muscularis (also called the muscularis externa). The mucosa is the innermost layer, and functions in absorption and secretion. It also joins the mucosa to the bulk of underlying smooth muscle (fibers running circularly within layer of longitudinal muscle). Submucosa. The Tissue Level of Organization, Chapter 6. e. SMALL INTESTINE - It is the longest part of the alimentary canal and comprises three parts- Duodenum, Jejunum, and Ileum. In the mouth and pharynx, it consists of skeletal muscle that aids in swallowing. It is composed of two different regions: the parietal peritoneum, which lines the abdominal wall, and the visceral peritoneum, which envelopes the abdominal organs (Figure 23.4). As its name implies, the submucosa lies immediately beneath the mucosa. Left, right, caudate, and quadrate lobes. Lipids are absorbed via lacteals, tiny structures of the lymphatic system. Four compounds possessed EC50 values less than or equal to 11 M. David N. Shier, Jackie L. Butler, Ricki Lewis, Hole's Essentials of Human Anatomy and Physiology, David Shier, Jackie Butler, John Hole, Ricki Lewis. Muscularis: voluntary swallowing 4. General structure of the gut wall: This cross section shows the mucosa in relation to the interior space, or lumen. The Cardiovascular System: Blood Vessels and Circulation, Chapter 21. consent of Rice University. Also called the gastrointestinal (GI) tract or gut, the alimentary canal (aliment- = "to nourish") is a one-way tube about 7.62 meters (25 feet) in length during life and closer to 10.67 meters (35 feet) in length when measured after death, once smooth muscle tone is lost. 1.2 Structural Organization of the Human Body, 2.1 Elements and Atoms: The Building Blocks of Matter, 2.4 Inorganic Compounds Essential to Human Functioning, 2.5 Organic Compounds Essential to Human Functioning, 3.2 The Cytoplasm and Cellular Organelles, 4.3 Connective Tissue Supports and Protects, 5.3 Functions of the Integumentary System, 5.4 Diseases, Disorders, and Injuries of the Integumentary System, 6.6 Exercise, Nutrition, Hormones, and Bone Tissue, 6.7 Calcium Homeostasis: Interactions of the Skeletal System and Other Organ Systems, 7.6 Embryonic Development of the Axial Skeleton, 8.5 Development of the Appendicular Skeleton, 10.3 Muscle Fiber Excitation, Contraction, and Relaxation, 10.4 Nervous System Control of Muscle Tension, 10.8 Development and Regeneration of Muscle Tissue, 11.1 Describe the roles of agonists, antagonists and synergists, 11.2 Explain the organization of muscle fascicles and their role in generating force, 11.3 Explain the criteria used to name skeletal muscles, 11.4 Axial Muscles of the Head Neck and Back, 11.5 Axial muscles of the abdominal wall and thorax, 11.6 Muscles of the Pectoral Girdle and Upper Limbs, 11.7 Appendicular Muscles of the Pelvic Girdle and Lower Limbs, 12.1 Structure and Function of the Nervous System, 13.4 Relationship of the PNS to the Spinal Cord of the CNS, 13.6 Testing the Spinal Nerves (Sensory and Motor Exams), 14.2 Blood Flow the meninges and Cerebrospinal Fluid Production and Circulation, 16.1 Divisions of the Autonomic Nervous System, 16.4 Drugs that Affect the Autonomic System, 17.3 The Pituitary Gland and Hypothalamus, 17.10 Organs with Secondary Endocrine Functions, 17.11 Development and Aging of the Endocrine System, 19.2 Cardiac Muscle and Electrical Activity, 20.1 Structure and Function of Blood Vessels, 20.2 Blood Flow, Blood Pressure, and Resistance, 20.4 Homeostatic Regulation of the Vascular System, 20.6 Development of Blood Vessels and Fetal Circulation, 21.1 Anatomy of the Lymphatic and Immune Systems, 21.2 Barrier Defenses and the Innate Immune Response, 21.3 The Adaptive Immune Response: T lymphocytes and Their Functional Types, 21.4 The Adaptive Immune Response: B-lymphocytes and Antibodies, 21.5 The Immune Response against Pathogens, 21.6 Diseases Associated with Depressed or Overactive Immune Responses, 21.7 Transplantation and Cancer Immunology, 22.1 Organs and Structures of the Respiratory System, 22.6 Modifications in Respiratory Functions, 22.7 Embryonic Development of the Respiratory System, 23.2 Digestive System Processes and Regulation, 23.5 Accessory Organs in Digestion: The Liver, Pancreas, and Gallbladder, 23.7 Chemical Digestion and Absorption: A Closer Look, 25.1 Internal and External Anatomy of the Kidney, 25.2 Microscopic Anatomy of the Kidney: Anatomy of the Nephron, 25.3 Physiology of Urine Formation: Overview, 25.4 Physiology of Urine Formation: Glomerular Filtration, 25.5 Physiology of Urine Formation: Tubular Reabsorption and Secretion, 25.6 Physiology of Urine Formation: Medullary Concentration Gradient, 25.7 Physiology of Urine Formation: Regulation of Fluid Volume and Composition, 27.3 Physiology of the Female Sexual System, 27.4 Physiology of the Male Sexual System, 28.4 Maternal Changes During Pregnancy, Labor, and Birth, 28.5 Adjustments of the Infant at Birth and Postnatal Stages. It includes blood and lymphatic vessels (which transport absorbed nutrients), and a scattering of submucosal glands that release digestive secretions. They transport the protein and carbohydrate nutrients absorbed by mucosal cells after food is digested in the lumen. Gastrointestinal (GI) Tract: The GI tract functions to provide the transportation, digestion and absorption of food that we ingest through our mouth. Instead of serosa, the mouth, pharynx, and esophagus have a dense sheath of collagen fibers called the adventitia. Deep Churn Prediction Method for Telecommunication Industry A small light source shines upward from the bottom of a $35 \mathrm{~cm}$-deep pond. Name the four types of teeth and the three main parts of a typical tooth. Also called the gastrointestinal (GI) tract or gut, the alimentary canal (aliment- = "to nourish") is a one-way tube about 7.62 meters (25 feet) in length during life and closer to 10.67 meters (35 feet) in length when measured after death, once smooth muscle tone is lost. The Cellular Level of Organization, Chapter 4. CliffsNotes study guides are written by real teachers and professors, so no matter what you're studying, CliffsNotes can ease your homework headaches and help you score high on exams. Chemical peritonitis can develop any time the wall of the alimentary canal is breached, allowing the contents of the lumen entry into the peritoneal cavity. The lamina propria also contains the mucosaassociated lymphoid tissue (MALT), nodules of lymphatic tissue bearing lymphocytes and macrophages that protect the GI tract wall from bacteria and other pathogens that may be mixed with food. In some regions, the circular layer of smooth muscle enlarges to form sphincters, circular muscles that control the opening and closing of the lumen (such as between the stomach and small intestine). Magnetically Actuated Continuum Medical Robots: A Review - Yang Name the nutrient that may be related to each of the following: a. iron-deficiency anemia b. osteoporosis c. dehydration d. high blood pressure. What is the importance of the mesenteries? Interspersed among its epithelial cells are goblet cells, which secrete mucus and fluid into the lumen, and enteroendocrine cells, which secrete hormones into the interstitial spaces between cells. Anatomy and physiology of the gastrointestinal tract (git) - SlideShare Muscularis externa. What layer of the alimentary canal tissue is capable of helping to protect the body against disease, and through what mechanism? Epithelial Tissue: Structure with Diagram, Function, Types and - BYJUS The GI tract is composed of four layers. The mucosa is the innermost layer, and functions in absorption and secretion. the pyloric sphincter. Deeper connective tissue which supports the mucosa Its functions are to mix food with stomach acid and break food down into smaller particles using chemical and mechanical digestion. What are the layers of the gastrointestinal tract? What are their Even so, the mortality rate still ranges from 30 to 40 percent. Biosensors | Free Full-Text | Last Trends in Point-of-Care (POC What are some possible roles introns might have? At the same time, the digestive system provides nutrients to the heart muscle and vascular tissue to support their functioning. Organs of the Alimentary Canal The Mouth and Oral cavity. Mucosa: epithelium - secretion and absorption; lamina propria - nutrient absorption; muscularis muscosae - increases surface area (for digestion & absorption) 2. submucosa: receive absorbed food molecules 3. Even more severe peritonitis is associated with bacterial infections seen with appendicitis, colonic diverticulitis, and pelvic inflammatory disease (infection of uterine tubes, usually by sexually transmitted bacteria). 120K views 10 years ago This video describes the functions of the 4 layers of the Alimentary canal. As is the case with all body systems, the digestive system does not work in isolation; it functions cooperatively with the other systems of the body. describe the four layers of the gi tract. From the inside out they are called: mucosa, submucosa, muscularis, and serosa. ANATOMY AND PHYSIOLOGY Individual Components of the Gastrointestinal System Oral cavity The oral cavity or mouth is responsible for the intake of food. bookmarked pages associated with this title. The third layer of the alimentary canal is the muscalaris (also called the muscularis externa). In general, sympathetic activation (the fight-or-flight response) restricts the activity of enteric neurons, thereby decreasing GI secretion and motility. Wise, Eddie Johnson, Brandon Poe, Dean H. Kruse, Oksana Korol, Jody E. Johnson, Mark Womble, Peter DeSaix. The idea of this style focuses on last years' sudden surge in popularity for plants as dcor. The blood vessels serving the digestive system have two functions. Table 23.1 gives a quick glimpse at how these other systems contribute to the functioning of the digestive system. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License . Submucosal- nerve network between the mucosa and submucosa. Thus, the location of these organs is described as retroperitoneal. Digestive System: Histology of the Alimentary Canal - Anatomy Describe the mechanical and chemical digestion of food entering the stomach Describe any absorption that happens in the stomach Although a minimal amount of digestion occurs in the mouth, chemical digestion really gets underway in the stomach, primarily as the initial site of protein digestion. { "22.5A:_Mucosa" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.5B:_Submucosa" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.5C:_Muscularis" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.5D:_Serosa" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, { "00:_Front_Matter" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.01:_Overview_of_the_Digestive_System" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.02:_Nervous_System_of_the_Digestive_System" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.03:_The_Peritoneum" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.04:_The_Alimentary_Canal" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.05:_Layers_of_the_Alimentary_Canal" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.07:_The_Liver" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.08:_The_Gallbladder" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.09:_The_Pancreas" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.10:_The_Small_Intestine" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.11:_The_Large_Intestine" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.12:_Chemical_Digestion" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.13:_Absorption" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.14:_Phases_of_Digestion" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.6:_The_Stomach" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "zz:_Back_Matter" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, [ "article:topic", "license:ccbysa", "showtoc:no" ], https://med.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fmed.libretexts.org%2FBookshelves%2FAnatomy_and_Physiology%2FAnatomy_and_Physiology_(Boundless)%2F22%253A_Digestive_System%2F22.05%253A_Layers_of_the_Alimentary_Canal%2F22.5A%253A_Mucosa, \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}}}\) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\), status page at https://status.libretexts.org, Describe the structure and function of the mucosa of the GI tract. It contains blood vessels, nerve endings, lymph nodules, and lymphatic vessels. What anatomical feature of the stomach allows the organ to form chyme? Although the small intestine is the workhorse of the system, where the majority of digestion occurs, and where most of the released nutrients are absorbed into the blood or lymph, each of the digestive system organs makes a vital contribution to this process (Figure 23.2). If a person becomes overly anxious, sympathetic innervation of the alimentary canal is stimulated, which can result in a slowing of digestive activity. Answered: Name the four layers of the | bartleby The mucosae (singular: mucosa) are highly specialized in each organ of the gastrointestinal tract in order to deal with different digestive tract conditions. Both the mouth and anus are open to the external environment; thus, food and wastes within the alimentary canal are technically considered to be outside the body. Each layer has a different function and quality, which makes it unique. Note that during fetal development, certain digestive structures, including the first portion of the small intestine (called the duodenum), the pancreas, and portions of the large intestine (the ascending and descending colon, and the rectum) remain completely or partially posterior to the peritoneum. Here's how these organs work together in your digestive system. Muscular layer 4. An Introduction to the Human Body, Chapter 2. The wall of the digestive tract has four layers or tunics: Mucosa Submucosa Muscular layer Serous layer or serosa The mucosa, or mucous membrane layer, is the innermost tunic of the wall. The contractions of these layers promote mechanical digestion, expose more of the food to digestive chemicals, and move the food along the canal. Reaching superconductivity in graphene layer by layer Below this point, the alimentary canal is supplied with blood by arteries branching from the abdominal aorta. Peritonitis is life threatening and often results in emergency surgery to correct the underlying problem and intensive antibiotic therapy. Do parts ac for the situation obtained after electrostatic equilibrium is reached. The main function of the organs of the alimentary canal is to nourish the body. Thomas Lane - Associate Director - LinkedIn It is part of the digestive tract, located between the esophagus and the duodenum. Name the structure that forms the roof of the mouth. The Cardiovascular System: The Heart, Chapter 20. Mucosa, submucosa, muscularis externa, and serosa. 2. What is the importance of the mesenteries? The stomach is a key part of the gastrointestinal (GI) tract, sitting between the esophagus and duodenum. The Nervous System and Nervous Tissue, Chapter 13. Your IP address is listed in our blacklist and blocked from completing this request. Notice that the epithelium is in direct contact with the lumen, the space inside the alimentary canal. In turn, the digestive system provides the nutrients to fuel endocrine function. The enteric nervous system provides intrinsic innervation, and the autonomic nervous system provides extrinsic innervation. The stomach is equipped for its churning function by the addition of a third layer, the oblique muscle. Identify the structural characteristic of smooth muscle fibers. This layer comes in direct contact with digested food (chyme). The enteric nervous system helps regulate alimentary canal motility and the secretion of digestive juices, thus facilitating digestion. The structure of these layers varies, in different regions of the digestive system, depending on their function. 22.5B: Submucosa - Medicine LibreTexts 10. Gastrointestinal wall - Wikipedia It plays a primary role in the digestion of food and is also called the digestive tract. 3. As soon as food enters the mouth, it is detected by receptors that send impulses along the sensory neurons of cranial nerves. The muscularis in the small intestine is made up of a double layer of smooth muscle: an inner circular layer and an outer longitudinal layer. As soon as food enters the mouth, it is detected by receptors that send impulses along the sensory neurons of cranial nerves. As an Amazon Associate we earn from qualifying purchases. Stomach. The basic two-layer structure found in the small intestine is modified in the organs proximal and distal to it. Fluid, Electrolyte, and Acid-Base Balance, Lindsay M. Biga, Sierra Dawson, Amy Harwell, Robin Hopkins, Joel Kaufmann, Mike LeMaster, Philip Matern, Katie Morrison-Graham, Devon Quick & Jon Runyeon, Next: 23.2 Digestive System Processes and Regulation, Creative Commons Attribution-ShareAlike 4.0 International License, Blood supplies digestive organs with oxygen and processed nutrients; absorption of nutrients, Endocrine hormones help regulate secretion in digestive glands and accessory organs, Skin helps protect digestive organs and synthesizes vitamin D for calcium absorption, Mucosa-associated lymphoid tissue and other lymphatic tissue defend against entry of pathogens; lacteals absorb lipids; and lymphatic vessels transport lipids to bloodstream, Skeletal muscles support and protect abdominal organs, Sensory and motor neurons help regulate secretions and muscle contractions in the digestive tract, Respiratory organs provide oxygen and remove carbon dioxide, Bones help protect and support digestive organs, Kidneys convert vitamin D into its active form, allowing calcium absorption in the small intestine, Apron-like structure that lies superficial to the small intestine and transverse colon; a site of fat deposition in people who are overweight, Anchors the liver to the anterior abdominal wall and inferior border of the diaphragm, Suspends the stomach from the inferior border of the liver; provides a pathway for structures connecting to the liver, Vertical band of tissue anterior to the lumbar vertebrae and anchoring all of the small intestine except the initial portion (the duodenum), Attaches two portions of the large intestine (the transverse and sigmoid colon) to the posterior abdominal wall, Describe the organs of the alimentary canal from proximal to distal, and briefly state their function, Identify the accessory digestive organs and briefly state their function, Describe the four fundamental tissue layers of the alimentary canal and the function of each layer, Contrast the contributions of the enteric and autonomic nervous systems to digestive system functioning, Explain how the peritoneum anchors the digestive organs. Except where otherwise noted, textbooks on this site Our mission is to improve educational access and learning for everyone. Taste - Wikipedia The mucosa of the stomach is a simple columnar epithelium composed entirely of mucous cells that produce a protective layer of bicarbonate-rich alkaline mucus that clings to the stomach mucosa and protects the stomach wall from being damaged by acid and digested by enzymes. The wall of the alimentary canal has four basic tissue layers: the mucosa, submucosa, muscularis, and serosa. If you are the site owner (or you manage this site), please whitelist your IP or if you think this block is an error please open a support ticket and make sure to include the block details (displayed in the box below), so we can assist you in troubleshooting the issue. Contains the submucosal enteric neural plexus that controls GI secretions and localized blood flow. Anatomy and Physiology of the Gastrointestinal Tract and Associated (d) The shells are then connected to each other by a metal wire. In addition, the mucosa has a thin, smooth muscle layer, called the muscularis mucosa (not to be confused with the muscularis layer, described below). It is composed of three layers: The submucosa lies outside the mucosa. Reabsorption of water and compaction of feces. Lamina propriaIn addition to loose connective tissue, the lamina propria contains numerous blood and lymphatic vessels that transport nutrients absorbed through the alimentary canal to other parts of the body. How to Tell If You Are Over-Watering or Under-Watering your Orchids Solved Online Anatomy of the Digestive System - | Chegg.com What structure marks the division between the left and right lobe of the liver? On the mucosa layer, small finger-like projections called villi and microvilli help to increase surface area for nutrient absorption. The gastrointestinal (GI) tract is composed of four layers of tissue, known as tunics. Notice that the epithelium is in direct contact with the lumen, the space inside the alimentary canal. 23.1 Overview of the Digestive System - OpenStax The mesocolon is an extension of the visceral peritoneum that attaches the large intestine to the rear of the abdominal wall. 1. Layers of the Stomach | New Health Advisor Organ-specific differences in mercury speciation and accumulation By clicking on this link, you can watch a short video of what happens to the food you eat as it passes from your mouth to your intestine. Submucosa: connective tissue layer lying just below mucosa and contains many blood vessels and nerves. His mother picked his middle name after a famous painter, Anthony Van Dyck. the epithelium is simple columnar, and is organized into gastric pits and glands to deal with secretion. The easiest way to understand the digestive system is to divide its organs into two main categories. The The mucosa is the innermost layer. From the inside out they are called the mucosa, submucosa, muscularis externa, and serosa. This system exhibited good correlation (r = 0.998) with a slope of 0.989 and intercept of 0.827, displaying good agreement with reference methods and existing parameters present on the market, i.e., YSI 2300 whole blood/plasma analyzer (Yellow Springs . Present only in the region of the alimentary canal within the abdominal cavity, it consists of a layer of visceral peritoneum overlying a layer of loose connective tissue. Name the four major regions of the stomach in order from its connection with the esophagus to the small intestine. Accessory digestive organs, despite their name, are critical to the function of the digestive system. Describe the development of the body cavities 3. The veins that collect nutrient-rich blood from the small intestine (where most absorption occurs) empty into the hepatic portal system. The blood vessels serving the digestive system have two functions. Compare the submucosal plexus with the deeper myenteric plexus. The stomach can perform these roles due to the layers of the stomach wall. Layers of the Gastrointestinal Tract - Nursing Lecture The blood vessels second function is to supply the organs of the alimentary canal with the nutrients and oxygen needed to drive their cellular processes. The following is a description of the various types of serosae associated with the digestive system: The adventitia is the serous membrane that lines the muscularis externa of the oral cavity, pharynx, esophagus, and rectum. Water vapor creates all clouds and precipitation. Spindle-shaped; lack T tubules, myofibrils, and sarcomeres. The small intestine has four tissue layers: The serosa is the outermost layer of the intestine. The mesentery is an extension of the visceral peritoneum that attaches the small intestine to the rear abdominal wall. Peritonitis is life threatening and often results in emergency surgery to correct the underlying problem and intensive antibiotic therapy. Name the four layers of the digestive tract from superficial to deep. The Gastrointestinal Tract - TeachMeAnatomy Accessory digestive organs comprise the second group and are critical for orchestrating the breakdown of food and the assimilation of its nutrients into the body. The lamina propria also serves an immune function by housing clusters of lymphocytes, making up the mucosa-associated lymphoid tissue (MALT). Name the four layers of the GI tract, and describe their functions. 1. Stomach histology: Mucosa, glands and layers | Kenhub In the esophagus, the epithelium is stratified, squamous, and non-keratinizing, for protective purposes. It includes blood and lymphatic vessels (which transport absorbed nutrients), and a scattering of submucosal glands that release digestive secretions. Removing #book# Anatomy Chapter 21 Flashcards | Quizlet The structure of these layers varies, in different regions of the digestive system, depending on their function. The mucosa, composed of simple epithelium cells, is the innermost layer of the gastrointestinal (GI) tract.