Describe the development of the body cavities 3. 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). 2. Submucosal- nerve network between the mucosa and submucosa. Below this point, the alimentary canal is supplied with blood by arteries branching from the abdominal aorta. A&P: Chapter 38 Section: Organization of the Digestive System Awarded 25 points out of 25 possible points. The system is much more complex. The mass of each biological compartment was assumed to be a fixed percentage of the core body mass, following prior work (Bryden, 1971; Laws et al., 2003).The model uses allometric relationships to update the mass of each compartment daily that captures the effects of growth dilution on tissue Hg concentrations and the rapid growth of ringed seal pups (Hickie et al., 2005). Organs of the Alimentary Canal The Mouth and Oral cavity. The GI tract contains four layers: the innermost layer is the mucosa, underneath this is the submucosa, followed by the muscularis propria and finally, the outermost layer - the adventitia. 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. 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. The GI tract is composed of four layers. If $V$ equals a constant throughout a given region of space what can you say about $\mathrm{E}$ in that region? Mucosa. Even after development is complete, they maintain a connection to the gut by way of ducts. Composed of 3 layers (epithelial, areolar connective, smooth muscle) Contains lymph tissue. The easiest way to understand the digestive system is to divide its organs into two main categories. The lamina propria of the mucosa contains lymphoid tissue that makes up the MALT and responds to pathogens encountered in the alimentary canal. In the rest of the digestive tract, it consists of smooth muscle (three layers in the stomach, two layers in the small and large intestines) and associated nerve fibers. What anatomical feature of the stomach allows the organ to form chyme? 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. 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). When your great grandparents and even your parents were young, the mortality from peritonitis was high. The stomach is a key part of the gastrointestinal (GI) tract, sitting between the esophagus and duodenum. Blood vessels and lymphatic vessels present in this layer provide nutrients to the epithelial layer, distribute hormones produced in the epithelium, and absorb end products of digestion from the lumen. Rather, this blood is diverted to the liver where its nutrients are off-loaded for processing before blood completes its circuit back to the heart. Thus, the location of these organs is described as retroperitoneal. 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 different structures and functions. The gastrointestinal wall is inflamed in a number of conditions. Muscularis mucosaeThis thin layer of smooth muscle is in a constant state of tension, pulling the mucosa of the stomach and small intestine into undulating folds. consent of Rice University. Then, draw AND describe the specific structural and functional differences in the inner lining of the esophagus, stomach, small intestine and large intestine in the appropriate boxes below. The mesocolon is an extension of the visceral peritoneum that attaches the large intestine to the rear of the abdominal wall. What roles do exons have? Imagine a sheet of material just one layer of atoms thickless than a millionth . This process of rapid renewal helps preserve the health of the alimentary canal, despite the wear and tear resulting from continued contact with foodstuffs. 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. The mucosa, composed of simple epithelium cells, is the innermost layer of the gastrointestinal (GI) tract. At the same time, the digestive system provides nutrients to the heart muscle and vascular tissue to support their functioning. Name the major functions of the large intestine. Removing #book# Contains the submucosal enteric neural plexus that controls GI secretions and localized blood flow, David N. Shier, Jackie L. Butler, Ricki Lewis, Charles Welsh, Cynthia Prentice-Craver, David Shier, Jackie Butler, Ricki Lewis, Hole's Essentials of Human Anatomy and Physiology, David Shier, Jackie Butler, John Hole, Ricki Lewis. The submucosal plexus (plexus of Meissner) lies in the submucosal layer and is responsible for regulating digestive secretions and reacting to the presence of food (see Figure 23.1.2). The Tissue Level of Organization, Chapter 6. The stomach is equipped for its churning function by the addition of a third layer, the oblique muscle. The most variation is seen in the epithelium tissue layer of the mucosa. Support/stabilize the organs of the abdominopelvic cavity and route for blood. We recommend using a Extrinsic innervations of the alimentary canal are provided by the autonomic nervous system, which includes both sympathetic and parasympathetic nerves. Four layers of the Gastointestinal Tract The GI tract contains four layers: the innermost layer is the mucosa, underneath this is the submucosa, followed by the muscularis propria and finally, the outermost layer - the adventitia. describe the four layers of the gi tract. Which is more efficient in propelling intestinal contents along the digestive tract: peristalsis or segmentation? Except where otherwise noted, textbooks on this site The mucosa consists of the epitheliumitself and also the supporting loose connective tissue, called lamina propria, immediately beneath the epithelium. The serosa is the portion of the alimentary canal superficial to the muscularis. How does this change in consistency facilitate your gaining nutrients from food? 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). 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. A small light source shines upward from the bottom of a $35 \mathrm{~cm}$-deep pond. It is made up of three layers: the epithelium, lamina propria, and muscularis mucosae. Epithelial cells have a very brief lifespan, averaging from only a couple of days (in the mouth) to about a week (in the gut). On the mucosa layer, small finger-like projections called villi and microvilli help to increase surface area for nutrient absorption. Muscularis externa. Reabsorption of water and compaction of feces. Dec 13, 2022 OpenStax. The basic two-layer structure found in the small intestine is modified in the organs proximal and distal to it. Name the four layers of the digestive tract from superficial to deep. Choose a modest trial pack with just two or four candies if you want to try these gummies out quickly. Name the four types of teeth and the three main parts of a typical tooth. Together, these are called accessory organs because they sprout from the lining cells of the developing gut (mucosa) and augment its function; indeed, you could not live without their vital contributions, and many significant diseases result from their malfunction. The alimentary canal is the pathway (a tube-like structure) that starts from the mouth and ends in the anus. 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. Contribution of Other Body Systems to the Digestive System. The third layer with high autonomy is defined as semiautonomous navigation, transferring the decision priority to the system. Mucosa: epithelium - secretion and absorption; lamina propria - nutrient absorption; muscularis muscosae - increases surface area (for digestion & absorption) 2. submucosa: receive absorbed food molecules 3. This season, you are right on trend if you explore the depths and layers of this often overlooked color. It has four parts- cardiac, fundus, body and pyloric portion. The celiac trunk services the liver, stomach, and duodenum, whereas the superior and inferior mesenteric arteries supply blood to the remaining small and large intestines. 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 . The gustatory system or sense of taste is the sensory system that is partially responsible for the perception of taste (flavor). 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. The It is composed of three layers: The submucosa lies outside the mucosa. The layers are discussed below, from the inside lining of the tract to the outside lining: The mucosa is a mucous membrane that lines the inside of the digestive tract from mouth to anus. The contractions of these layers promote mechanical digestion, expose more of the food to digestive chemicals, and move the food along the canal. Anatomy & Physiology by Lindsay M. Biga, Sierra Dawson, Amy Harwell, Robin Hopkins, Joel Kaufmann, Mike LeMaster, Philip Matern, Katie Morrison-Graham, Devon Quick & Jon Runyeon is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License, except where otherwise noted. The structure of these layers varies, in different regions of the digestive system, depending on their function. 2. The submucosal plexus (plexus of Meissner) lies in the submucosal layer and is responsible for regulating digestive secretions and reacting to the presence of food (see Figure 23.3). The accessory digestive structures include the teeth, tongue, salivary glands, liver, pancreas, and gallbladder. A team of researchers from the Institute of Science and Technology Austria (ISTA) and the Weizmann Institute of Science has studied what happens when they layer four sheets of it on top of each other and how this can lead to new forms of exotic superconductivity. Mucosa - 2. The smooth muscle is responsible for movement of food by peristalsis and mechanical digestion by segmentation. Table 23.1 gives a quick glimpse at how these other systems contribute to the functioning of the digestive system. and any corresponding bookmarks? Describe the anatomy of the intestinal mucosa. 1-The wall of the digestive tract has four layers- 1-Mucosa 2-Sub mucosa 3-Mucosal layer 4-Serosal layer or Serosa Each of these layers have different tissues and functions,the mucosa is the inner most layer and its main function is in anso View the full answer In this study, various types of learning strategies are investigated to address this challenge and . The four layers of the alimentary or digestive tract are listed as: Serosa: It is formed of the mesothelium and is found at the exterior part of the canal. A broad layer of dense connective tissue, it connects the overlying mucosa to the underlying muscularis. 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 structure of these layers varies, in different regions of the digestive system, depending on their function. Quiz: Function of the Digestive System. Lipids are absorbed via lacteals, tiny structures of the lymphatic system. This process of rapid renewal helps preserve the health of the alimentary canal, despite the wear and tear resulting from continued contact with foodstuffs. Name the three regions of the small intestine from proximal to distal. Each layer has different tissues and functions. Why? His mother picked his middle name after a famous painter, Anthony Van Dyck. Muscular layer 4. Instead of serosa, the mouth, pharynx, and esophagus have a dense sheath of collagen fibers called the adventitia. If you are redistributing all or part of this book in a print format, The epithelium is the innermost layer and it is responsible for most digestive, absorptive, and secretory processes. To appreciate just how demanding the digestive process is on the cardiovascular system, consider that while you are resting and digesting, about one-fourth of the blood pumped with each heartbeat enters arteries serving the intestines. secretory function in stomach. 1. This venous network takes the blood into the liver where the nutrients are either processed or stored for later use. The gallbladder releases bile, which is responsible as a buffer and emulsification, while the pancreas provides enzymes that break down starches, lipids, nucleic acids & proteins. Intrinsic innervation of much of the alimentary canal is provided by the enteric nervous system, which runs from the esophagus to the anus, and contains approximately 100 million motor, sensory, and interneurons (unique to this system compared to all other parts of the peripheral nervous system). The lamina propria is a layer of connective tissue that is unusually cellular compared to most connective tissue. While the colon has two layers like the small intestine, its longitudinal layer is segregated into three narrow parallel bands, the tenia coli, which make it look like a series of pouches rather than a simple tube. 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. It is made of: epithelium; lamina propria Swollen veins in the rectum that may result from straining during defecation. Starting from the lumen and moving outwards, these layers are the mucosa, submucosa, muscularis, and serosa, which is continuous with the mesentery (see Figure 23.3). Previous The mesocolon is the portion of the mesentery serving the colon and is considered part of the larger mesentery organ. lamina propria. Submucosa - 3. In contrast, parasympathetic activation (the rest-and-digest response) increases GI secretion and motility by stimulating neurons of the enteric nervous system. All digestive organs play integral roles in the life-sustaining process of digestion. Aggressive surgery, improvements in anesthesia safety, the advance of critical care expertise, and antibiotics have greatly improved the mortality rate from this condition. Left, right, caudate, and quadrate lobes. Are you sure you want to remove #bookConfirmation# 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. However, if you are a seasoned user . Each accessory digestive organ aids in the breakdown of food (Figure 23.3). Structure of the Muscularis Externa 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. What structure marks the division between the left and right lobe of the liver? EpitheliumIn the mouth, pharynx, esophagus, and anal canal, the epithelium is primarily a non-keratinized, stratified squamous epithelium. The mucosa is the innermost layer, and functions in absorption and secretion. In the mouth and pharynx, it consists of skeletal muscle that aids in swallowing. The main organs that make up the digestive system (in order of their function) are the mouth, esophagus, stomach, small intestine, large intestine, rectum and anus. Blood vessels, lymphatic vessels, and nerves (all supplying the . Answer and Explanation: 1. Describe the four layers of the gastrointestinal tract walls, including locations. There are goblet cells present, which secrete mucus. When you consider that the alimentary canal is exposed to foodborne bacteria and other foreign matter, it is not hard to appreciate why the immune system has evolved a means of defending against the pathogens encountered within it. The mucosa of the remainder of the GI tract is a delicate layer of simple columnar epithelium designed for absorption and secretion. Rather, this blood is diverted to the liver where its nutrients are off-loaded for processing before blood completes its circuit back to the heart. Despite the fact that people use it on a daily basis, most people only have a basic understanding of what it is and how it works. The blood vessels serving the digestive system have two functions. Part B: First, describe the four major layers of the GI tract that are found from esophagus to anus. Muscularis: voluntary swallowing 4. The gastrointestinal (GI) tract is composed of four layers of tissue, known as tunics. From the inside out they are called: mucosa, submucosa, muscularis, and serosa. It is also important for the telecommunication industry to obtain a high profit. 1. Between those two points, the canal is modified as the pharynx, esophagus, stomach, and small and large intestines to fit the functional needs of the body. The wall of the GI tract from the esophagus to the anal canal has four-layer from deep to superficial, are the mucosa, submucosa, muscularis and serosa/adventitia. Explanation: Oesophagus is exceptional in having a compound squamous epithelium on the inside and an adventitia on the outside. The mucosa surrounds the lumen, or open space within the digestive tube. This book uses the These lymphocyte clusters are particularly substantial in the distal ileum where they are known as Peyers patches. Creative Commons Attribution License 3. It is rounded and hollow, and located near the diaphragm in the left part of your abdomen. Food, mucus, and digestive juices pass through the lumen, and the mucosa comes in direct contact with digested food (chyme). FormalPara Learning Outcomes . Submucosa: connective tissue layer lying just below mucosa and contains many blood vessels and nerves. The first group is the organs that make up the alimentary canal. Do parts ac for the situation obtained after electrostatic equilibrium is reached. Name the four layers of the digestive tract from superficial to deep. the epithelium is simple columnar, and is organized into gastric pits and glands to deal with secretion. The visceral peritoneum includes multiple large folds that envelope various abdominal organs, holding them to the dorsal surface of the body wall. The gastrointestinal (GI) tract is composed of four layers of tissue, known as tunics. In addition, the mucosa has a thin, smooth muscle layer, called the muscularis mucosae (not to be confused with the muscularis layer, described below). The Cellular Level of Organization, Chapter 4. Even so, the mortality rate still ranges from 30 to 40 percent. The digestive organs within the abdominal cavity are held in place by the peritoneum, a broad serous membranous sac made up of squamous epithelial tissue surrounded by connective tissue. Your IP address is listed in our blacklist and blocked from completing this request. Temporary storage of bile produced by the liver. Only through the process of absorption do the nutrients in food enter into and nourish the bodys inner space.. Two concentric spherical metal shells are insulated from each other and from the surroundings. There are 4 layers in gastrointestinal tract: from inside to outside these are mucosa, submucosa, muscular layer and serosa. Since the mucosa is the innermost layer within the GI tract, it surrounds an open space known as the lumen. Young, James A. . The mucosa is the innermost layer of the GI tract. Reflect upon the structure of the bowel layers itself and describe the role each of these layers has in relation to peristalsis. Between the bases of the villi are intestinal glands lined by enteroendocrine, mucous, and stem cells. Gastric glands. Inflammation of the peritoneum is called peritonitis. The lamina propria lies outside the epithelium. The hard palate, a bony structure, forms the roof of the mouth. Name the four major regions of the stomach in order from its connection with the esophagus to the small intestine. The pelvic cavity contains the urinary bladder, rectum, and internal reproductive organs. In turn, the digestive system provides the nutrients to fuel endocrine function. are licensed under a, Structural Organization of the Human Body, Elements and Atoms: The Building Blocks of Matter, Inorganic Compounds Essential to Human Functioning, Organic Compounds Essential to Human Functioning, Nervous Tissue Mediates Perception and Response, Diseases, Disorders, and Injuries of the Integumentary System, Exercise, Nutrition, Hormones, and Bone Tissue, Calcium Homeostasis: Interactions of the Skeletal System and Other Organ Systems, Embryonic Development of the Axial Skeleton, Development and Regeneration of Muscle Tissue, Interactions of Skeletal Muscles, Their Fascicle Arrangement, and Their Lever Systems, Axial Muscles of the Head, Neck, and Back, Axial Muscles of the Abdominal Wall, and Thorax, Muscles of the Pectoral Girdle and Upper Limbs, Appendicular Muscles of the Pelvic Girdle and Lower Limbs, Basic Structure and Function of the Nervous System, Circulation and the Central Nervous System, Divisions of the Autonomic Nervous System, Organs with Secondary Endocrine Functions, Development and Aging of the Endocrine System, The Cardiovascular System: Blood Vessels and Circulation, Blood Flow, Blood Pressure, and Resistance, Homeostatic Regulation of the Vascular System, Development of Blood Vessels and Fetal Circulation, Anatomy of the Lymphatic and Immune Systems, Barrier Defenses and the Innate Immune Response, The Adaptive Immune Response: T lymphocytes and Their Functional Types, The Adaptive Immune Response: B-lymphocytes and Antibodies, Diseases Associated with Depressed or Overactive Immune Responses, Energy, Maintenance, and Environmental Exchange, Organs and Structures of the Respiratory System, Embryonic Development of the Respiratory System, Digestive System Processes and Regulation, Accessory Organs in Digestion: The Liver, Pancreas, and Gallbladder, Chemical Digestion and Absorption: A Closer Look, Regulation of Fluid Volume and Composition, Fluid, Electrolyte, and Acid-Base Balance, Human Development and the Continuity of Life, Anatomy and Physiology of the Testicular Reproductive System, Anatomy and Physiology of the Ovarian Reproductive System, Development of the Male and Female Reproductive Systems, Changes During Pregnancy, Labor, and Birth, Adjustments of the Infant at Birth and Postnatal Stages. Describe the arrangement and subdivisions of the thorax 5. Taste is the perception produced or stimulated when a substance in the mouth reacts chemically with taste receptor cells located on taste buds in the oral cavity, mostly on the tongue.Taste, along with olfaction and trigeminal nerve stimulation (registering texture . The wall of the alimentary canal is composed of four basic tissue layers: mucosa, submucosa, muscularis, and serosa. When your great grandparents and even your parents were young, the mortality from peritonitis was high. In the esophagus, the epithelium is stratified, squamous, and non-keratinizing, for protective purposes. Goblet cells secrete mucus that protects the epithelium from digestion, and endocrine cells secrete hormones into the blood. Alone among the GI tract, the stomach has a third layer of muscularis externa. The walls of the gastrointestinal (GI) tract are composed of how many layers of tissue? For example, when an ulcer perforates the stomach wall, gastric juices spill into the peritoneal cavity. Stomach. Epithelial cells have a very brief lifespan, averaging from only a couple of days (in the mouth) to about a week (in the gut). Name the nutrient that may be related to each of the following: a. iron-deficiency anemia b. osteoporosis c. dehydration d. high blood pressure. The stomach is equipped for its churning function by the addition of a third layer, the oblique muscle. By the end of this section, you will be able to: The function of the digestive system is to break down the foods you eat, release their nutrients, and absorb those nutrients into the body. The mucosa is referred to as a mucous membrane, because mucus production is a characteristic feature of gut epithelium. Accessibility StatementFor more information contact us atinfo@libretexts.orgor check out our status page at https://status.libretexts.org. Even so, the mortality rate still ranges from 30 to 40 percent. 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. Esophagus. He was the son of Henry Barlow Carter, a well-known artist and it is possible that he honed his natural talents with his father. The epithelium of the mucosa is particularly specialized, depending on the portion of the digestive system. Walls of the digestive tract have four concentric layers. Except in the mouth, esophagus, and anus where it's stratified squamous, the epithelium of mucosa is a simple columnar epithelium rich in mucus-secreting cells. Support/stabilize the organs of the abdominopelvic cavity and route for blood. Consider how understanding the function of the Gastro-intestinal (GI) tract is useful in the care of patients with surgical changes for example the formation of an ileostomy. The mucosae (singular: mucosa) are highly specialized in each organ of the gastrointestinal tract in order to deal with different digestive tract conditions. This layer comes in direct contact with digested food (chyme). It contains blood vessels, nerve endings, lymph nodules, and lymphatic vessels. The third layer of the alimentary canal is the muscularis (also called the muscularis externa). To appreciate just how demanding the digestive process is on the cardiovascular system, consider that while you are resting and digesting, about one-fourth of the blood pumped with each heartbeat enters arteries serving the intestines. The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. The peritoneal cavity is the space bounded by the visceral and parietal peritoneal surfaces. The serosa is the portion of the alimentary canal superficial to the muscularis. These lymphocyte clusters are particularly substantial in the distal ileum where they are known as Peyers patches. 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 space shared between the digestive and respiratory tracts. Each layer has a different function and quality, which makes it unique. The blood vessels serving the digestive system have two functions. Incisors, cuspids (canines), bicuspids (premolars), and molars. Compare the submucosal plexus with the deeper myenteric plexus. In the gastrointestinal tract, the submucosa is the layer of dense irregular connective tissue or loose connective tissue that supports the mucosa.
