Introduction
Paul Ong, Rachel Skittrall in Gastrointestinal Nursing, 2017
The gastrointestinal tract is made up of a hollow tube that travels through the body from the mouth to the anus. The tube is open to the exterior at both ends, and although it passes through body cavities, it is separate to the internal body environment. The wall of the tube is made up of four main layers: the mucosa, submucosa, muscularis externa and serosa (Figure 1.4). Each of these components is adapted throughout the length of the gastrointestinal tract according to its function to provide Physical and mechanical protectionMovementSecretionAbsorption
The Digestive (Gastrointestinal) System and Its Disorders
Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss in Understanding Medical Terms, 2020
Diseases affecting the digestive system can attack any portion of the gastrointestinal tract or its associated organs (see Table 6.1). Many of the diseases affecting the mouth only indirectly alter digestion by decreasing the effectiveness of chewing and are not usually considered digestive diseases (see Dental section). Other oral disorders, such as stomatitis (inflammation of the mouth), glossitis (inflammation of the tongue), and oral infections are often secondary to systemic diseases or are local disorders that do not affect digestion. Disorders of the remainder of the GI tract, however, are generally classified as digestive.
Management of Diabetic Gastroparesis
Emmanuel C. Opara, Sam Dagogo-Jack in Nutrition and Diabetes, 2019
The gastrointestinal tract is a hollow organ composed of mucosal, muscular, and neural components along with supporting cells, including ICCs and endothelial cells. The mucosa is surrounded by circular and longitudinal smooth muscle layers that promote the mechanical breakdown and propulsion of food within the GI tract, through coordinated contraction and relaxation events termed peristalsis. The neural component of the GI tract, the enteric nervous system (ENS), is an independent division of the peripheral nervous system responsible for regulating gut functions including motility, secretion and absorption [59]. To date, approximately 10–15 subtypes of myenteric and 4–5 subtypes of submucosal neurons have been identified, including excitatory and inhibitory motor neurons, interneurons, intrinsic primary afferent neurons (IPANs), and secretomotor and vasodilator neurons [60].
Hyaluronan-induced alterations of the gut microbiome protects mice against Citrobacter rodentium infection and intestinal inflammation
Published in Gut Microbes, 2021
Tangyou Mao, Chien-Wen Su, Qiaorong Ji, Chih-Yu Chen, Rongjun Wang, Deepak Vijaya Kumar, Jinggang Lan, Lefei Jiao, Hai Ning Shi
The gastrointestinal tract is a complex ecosystem harboring an enormous community of microorganisms that coexist with the host in a symbiotic relationship and play important roles in maintaining human health.14 This dynamic interaction between the microbiota and host is conducive to the maintenance of intestinal homeostasis, nutrient acquisition, energy regulation, and colonization resistance against enteropathogens.15 Therefore, targeted regulation of the composition and function of intestinal microbiota has been suggested to play an important role in maintaining the homeostatic innate and adaptive immune responses both systemically and in the gut in preventing bacterial enteropathogen infection. In the current study, we tested the hypothesis that hyaluronan-mediated alterations of the gut microbiome significantly modulated mucosal immunity against bacterial enteropathogens and intestinal inflammation. A better understanding of the role of hyaluronan in the regulation of the complex interactions between host gut microbiota, mucosal immune function, and inflammatory processes will facilitate the development of novel therapeutics for many critical diseases.
Current status and advances in esophageal drug delivery technology: influence of physiological, pathophysiological and pharmaceutical factors
Published in Drug Delivery, 2023
Ai Wei Lim, Nicholas J. Talley, Marjorie M. Walker, Gert Storm, Susan Hua
The esophagus is a part of the gastrointestinal tract (GI tract) that connects the pharynx to the stomach. It is a hollow, muscular channel that delivers swallowed food bolus to the stomach. The thickness of the esophageal wall in healthy individuals varies depending on the section of the esophagus, with the largest wall thickness during esophageal contraction of 4.70 mm (95%CI: 4.44-4.95) and during esophageal dilation of 2.11 mm (95%CI: 2.00-2.23) (Xia et al., 2009). The esophagus begins at the upper esophageal sphincter that is formed by the cricopharyngeal muscle and ends with the lower esophageal sphincter, which is surrounded by the crural diaphragm (Standring, 2020). While the average length of the esophagus in an adult is between 23 to 25 cm, the length in children at birth varies between 8 to 10 cm (Standring, 2020; Scott-Brown et al., 2008). The esophagus is lined with non-keratinized squamous epithelium in humans and the muscular elements are smooth muscle (Standring, 2020).
The Effects of Perioperative Probiotics on Postoperative Gastrointestinal Function in Patients with Brain Tumors: A Randomized, Placebo-Controlled Study
Published in Nutrition and Cancer, 2023
Mengyang Jiang, Xiaoyu Zhang, Yiqiang Zhang, Yang Liu, Ran Geng, Haixia Liu, Yongxing Sun, Baoguo Wang
The primary functions of the gastrointestinal tract are motility, secretion, absorption, and serving as a barrier. Nervous system disorders affecting gastrointestinal function are characterized primarily by abnormalities in motility rather than secretion (6). Gastrointestinal motility is regulated at multiple levels, including the central and enteric nervous systems as well as the microbiome (26,27). Surgery-induced stress and inflammatory responses activate the sympathetic and enteric nervous systems, leading to gastrointestinal dysfunction and thus disturbing motility and transit (28). This process involves the immune system, inflammatory cells, reactive enteric glia, neurons, smooth muscle cells, epithelial cells, and the microbiome in the intestinal lumen (8). Postoperative gastrointestinal dysfunction can not only cause short-term complications, but may also lead to long-term complications after inflammation subsides (29). The incidence of postoperative gastrointestinal dysfunction in adults with neurological diseases is more than twice that for individuals with non-neurological diseases (2).