The Digestive (Gastrointestinal) System and Its Disorders
Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss in Understanding Medical Terms, 2020
Nausea and vomiting generally occur together and can reflect the presence of acute abdominal emergencies, chronic indigestion, and acute systemic infections, as well as many diseases involving other body systems. They are often associated with abdominal pain. The medical term for vomiting is emesis.Colic can refer to spasmodic pains in the abdomen, to the paroxysms of pain seen in young infants, or to a variety of pain or cramping episodes due to a number of causes. Anorexia (loss of desire to eat) is a primary symptom in a number of disorders of the gastrointestinal tract and liver. Diverticula or pouches can occur along the intestinal wall. Meckel's diverticulum refers to such an area on the ileum that can produce ulceration and bleeding. Dlverticislosls denotes the presence of multiple sites; diverticulitis specifically describes inflammation.
Gastrointestinal Function and Toxicology in Canines
Shayne C. Gad in Toxicology of the Gastrointestinal Tract, 2018
Similar to the stomach, the small intestine possesses muscular contracting activities which facilitate both the mixing and propulsion of its contents. Segmental contractions ensure proper mixing, whereas peristaltic contractions move the chyme along the tract in an aboral direction. It is important to realize though that the mixing activity is never pure mixing and similarly as regards propulsion, propulsion is never purely propulsion and there is a great deal of overlap between the two. Reduced segmental activity can speed transit times, while reduced peristaltic activity can prolong transit times. As the wall of the small bowel becomes distended, this stretching stimulates the initiation of local ring-like contractions at various locations and intervals along the small intestine. Each of these contractions resembles or acts much like a hand squeezing a sausage-shaped balloon. These contractions can be isolated, irregularly spaced, regularly spaced or weak and irregularly spaced and occur at a frequency of about 12 per minute in the duodenum and jejunum and at a frequency of about 9 per minute in the ileum. The slow waves in the smooth muscle of the intestinal wall play an important role in the maintenance of segmental contracting activity, but the assistance of and contribution from the enteric nervous system is essential for normal function.
Peritoneal metastases
Anju Sahdev, Sarah J. Vinnicombe in Husband & Reznek's Imaging in Oncology, 2020
Gastrointestinal involvement usually affects the small bowel. Small nodules in the bowel wall are difficult to see on imaging. However, if the small bowel is well distended with CT or MRI enteroclysis, focal masses or enhancement are likely to be better seen. Tumour involvement can occur by serosal seeding or by direct bowel wall invasion from an adjacent tumour (Figures 33.2a, 33.19, 33.21, 33.22, and 33.23). Bowel obstruction may be from serosal metastases or associated adhesions, but is most commonly seen when the intestinal wall is invaded (Figure 33.24). Bowel obstruction has been reported in about 50% of cases at autopsy (53); CT findings suggesting bowel involvement include thickening and distortion. Haematogenous metastases also occur to the bowel wall and may be seen as small submucosal nodules and cause bowel wall thickening or larger discrete masses—these may ulcerate or cavitate (16). Breast cancer and lymphoma can cause diffuse gastric wall thickening, indistinguishable from primary scirrhous gastric carcinoma (17).
Comparative toxicity of three differently shaped carbon nanomaterials on Daphnia magna: does a shape effect exist?
Published in Nanotoxicology, 2018
Renato Bacchetta, Nadia Santo, Irene Valenti, Daniela Maggioni, Mariangela Longhi, Paolo Tremolada
The general morphology of daphnids, and some details from control samples are shown in Supplementary Figure S2 (available in the online version of the paper). Figure 4 shows the midgut from control samples, in which the gut muscolaris, the peritrophic membrane and the microvilli are well visible (Figure 4(A–C)). In particular, Figure 4(C) shows the width of the intestinal wall and the presence of the thick brush border on the apical portion of the digestive cells. Figure 5 shows detailed portions of the midgut from samples exposed to the three selected NPs, in which the differently shaped CNMs are well recognizable. These images evidence also the huge mass of CNMs filling the gut, confirming the digestive system as a preferential accumulation site for all NPs. The ultrastructural analyses by TEM were performed on the gut at this level.
Application of ultrasonography in predicting the biological risk of gastrointestinal stromal tumors
Published in Scandinavian Journal of Gastroenterology, 2022
Jing-Jing Guo, Xiu-Bin Tang, Qing-Fu Qian, Min-Ling Zhuo, Li-Wu Lin, En-Sheng Xue, Zhi-Kui Chen
Gastrointestinal submucosal tumors include GISTs, neuroendocrine tumors, leiomyomas, and ectopic pancreas, among others. Accurately distinguishing the gastrointestinal wall layer from which the tumor originated is the key to tumor differential diagnosis. With continuous technological development and technical refinement, transabdominal gastrointestinal ultrasonography has been gradually utilized in China. With effective gastrointestinal preparation and the use of oral gastrointestinal contrast agent or isotonic mannitol, the interference of gas and other gastrointestinal contents on ultrasound is significantly decreased. The mucosa, submucosa, muscularis propria, and serosa of the gastrointestinal wall can be displayed clearly in most patients by transabdominal gastrointestinal ultrasonography [19]. In addition, transabdominal gastrointestinal ultrasonography has advantages, such as convenient operation, good patient compliance, and no contraindications. For patients with a low BMI, high-frequency probes are available, and imaging quality similar to that of EUS can be obtained.
External validation and comparison of simple ultrasound activity score and international bowel ultrasound segmental activity score for Crohn’s disease
Published in Scandinavian Journal of Gastroenterology, 2023
Lu Wang, Chenjing Xu, Yanyan Zhang, Wenyu Jiang, Jingjing Ma, Hongjie Zhang
Additionally, the diagnostic potential of the IBUS-SAS was slightly higher than that of the SUS-CD (AUC = 0.895 vs. 0.835) without a significant difference. This may be attributed to the inclusion of inflammatory fat and intestinal wall stratification in the IBUS-SAS. The proliferation of mesenteric inflammatory fat is characteristic of active CD. Previous studies have confirmed that mesenteric inflammatory fat is significantly related to disease activity [26,27]. The stratification of the intestinal wall may also reflect CD activity to some extent. In severe CD, the layers of the intestinal wall disappear, which makes distinguishing the structure of each layer impossible, although the structure of the intestinal wall may reappear with the remission phase [28]. For mild lesions, intestinal wall layers will reappear with the remission of the disease. This panel of international, multidisciplinary experts has determined mesenteric inflammatory fat and loss of bowel wall stratification as valuable markers of disease activity [29]. Therefore, the IBUS-SAS can present more specific information on CD severity compared to the SUS-CD. The inter-rater reliability by two independent expert operators evaluating i-fat and BWS demonstrated good agreement, and the weighted kappa was 0.84 and 0.86, respectively (p < 0.001). This result highlights the importance of mesenteric inflammatory fat and intestinal wall stratification in US scoring systems.