Explore chapters and articles related to this topic
Gastrointestinal tract and salivary glands
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
The large intestine is approximately 1.5 m long from caecum to anus, with a variable calibre from between 9 and 3 cm. It lies peripheral to the small intestine, with the more lateral structures being relatively fixed in position. From the right iliac fossa where the terminal ileum communicates via the ileo-caecal valve, the ceacum extends superiorly as the ascending colon before it turns abruptly to the left, beneath the liver, at the hepatic flexure. Crossing the abdomen, the transverse colon turns inferiorly at the splenic flexure, where it continues as the descending colon. The bowel loops to a variable degree at the sigmoid colon, passing along the posterior wall of the pelvis where it merges with the rectum at the recto-sigmoid junction. The rectum is 13 cm long and is a dilated part of the large intestine, continuous with the anal canal and anus. The large intestine displays large sacculations known as haustra that are thought to slow the passage of digested matter. The relations of the large intestine are complex and variable as the bowel traverses the different regions of the abdomen (Figs 5.52a–c).
Designing for Upper Torso and Arm Anatomy
Published in Karen L. LaBat, Karen S. Ryan, Human Body, 2019
A relatively horizontal portion of the large intestine, segments of the small intestine, and parts of the supporting structure for the intestine, the mesentery, are also found near the lower ribs. The mesentery is a continuous connective tissue structure (Coffey & O’Leary, 2016). Blood vessels, nerves, and lymphatic vessels travel through the mesentery to the hollow small and large intestines. Large segments of small and large intestine and mesentery are also found in the mid torso and lower torso. The rectum, the most distal portion of the large intestine, fits almost entirely within the bony pelvis. There are 8.2 m (27 ft) of small intestine and 1 m (3 ft) of large intestine packed into the abdomen. Figure 4.29 shows the relationships of the intestines to the other abdominal organs and the exterior of the body.
Gastrointestinal system
Published in David A Lisle, Imaging for Students, 2012
Management options for rectal carcinoma include surgery, chemotherapy and radiotherapy. Surgery for rectal carcinoma is potentially curative and consists of complete removal of the rectum and surrounding mesorectal fat and lymphatics, i.e. total mesorectal excision (TME). TNM staging of rectal carcinoma may assist in directing management. TME may be used for tumours that have not invaded beyond the rectal wall, i.e. T1 or T2. For higher stage tumours, neoadjuvant chemotherapy or a combination of neoadjuvant chemotherapy and radiotherapy may be used prior to surgery. For advanced invasive disease or metastatic disease, non-curative surgery such as local excision and stoma may be used to palliate obstruction.
Effect of bladder and rectal loads on the vaginal canal and levator ani in varying pelvic floor conditions
Published in Mechanics of Advanced Materials and Structures, 2018
Arnab Chanda, Vinu Unnikrishnan
In the current work, a full-scale computational model of the female pelvic system along with the pelvic floor muscles was developed to study the effect of interaction between the various pelvic organs at different loading and pelvic floor conditions. Realistic geometrical models of the pelvic organs namely the urinary bladder, vaginal canal (uterus), rectum and pelvic floor muscle (levator ani) were considered. Nonlinear material models were used to characterize the mechanical properties of normal pelvic organ tissues, and a novel material model was developed to simulate the progressive weakening of the levator ani in prolapse. Appropriate constraints were selected based on studies in literature on functional anatomy of the female pelvis, and a forced volume expansion technique was used to simulate bladder and rectal loading conditions. In normal levator ani conditions, the effect of bladder and rectal loads on the induced stresses and displacements at the vaginal wall and levator ani were quantified for the first time. The vaginal and levator ani changes due to the diseased pelvic floor (simulated using the pelvic weakening material model) were investigated. One of the major limitation of the current model is the nonincorporation of a realistic anisotropic material model for the pelvic tissues, which would be a subject of future work, and will improve the accuracy of the quantitative results.
Simulation of the mobility of the pelvic system: influence of fascia between organs
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Mouhamadou Nassirou Diallo, Olivier Mayeur, Pauline Lecomte-Grosbras, Laurent Patrouix, Jean François Witz, François Lesaffre, Chrystle Rubod, Michel Cosson, Mathias Brieu
The external contour of the pelvic floor is assumed as fixed to simulate its attachment to the pelvis, as well as the upper part of the ligaments. The cervix is attached to the upper termination of the vagina. Similarly, the lower parts of the vagina and rectum are attached to the pelvic floor.
Design of experiment for optimization of 3D printing parameters of base plate structures in colostomy bag for newborns
Published in Journal of Industrial and Production Engineering, 2021
Chia Hung Yeh, Chia Man Chou, Chien Pang Lin
According to the American Cancer Society, approximately 15% of patients with colorectal cancer must undergo colostomy surgery to prolong their survival [1]. The appearance of patients who undergo surgical enterostomy is no different from that of the average person. However, in everyday life, when the intestines are excreted, it is not possible to discharge the excrement through the anus after surgery. Therefore, it is necessary to provide assistance through an auxiliary bag. In this regard, an improper ostomy bag is likely to cause leakage of the excrement, thus causing allergies or damage to the surrounding skin [2]. These problems deeply affect the patient’s physical condition and quality of life and cause changes in the patient’s body. The individual’s psychological and social impact is more physiological than injury-based. A colostomy can be in the small intestine of the upper gastrointestinal tract or in the colon of the lower gastrointestinal tract. The type of enterostomy also varies depending on the location of the lesion and the location of the operation. The distinction is as follows: (1) Permanent stoma: surgical removal of the anus and rectum, pulling the end of the sigmoid colon or descending the colon out of the left abdomen to make a stoma to defecate, as shown in Figure 1. The patient must both learn the use of stoma products and stoma lavage during hospitalization. Among them, stoma lavage is implemented after surgery, which requires enema training to maintain regular bowel habits. (2) Temporary stoma: If there are traumas around the anus, severe anal abscess, or an acute intestinal obstruction caused by disease when a patient undergoes large intestine surgery, those with the three conditions mentioned above will have the abdominal wall of the transverse colon pulled out to create a temporary colon stoma. When the patient recovers, the transverse colon is returned to the abdominal cavity. (3) Urostomy, also known as an artificial bladder: Patients with bladder cancer need to undergo a total cystectomy because of the disease. An opening is made in the right lower abdomen to drain the urine.