TissueDB/Tissues/Umbilical Cord
Umbilical cord is the cord connecting the fetus to the placenta, spanning from the fetal umbilicus to the centre of the placenta. It carries three vessels — two umbilical arteries returning deoxygenated blood to the placenta and one umbilical vein carrying oxygenated blood and nutrients back to the fetus — enclosed in Wharton's jelly, a gelatinous connective tissue composed mainly of mucopolysaccharides such as hyaluronic acid and chondroitin sulfate. It averages 50 to 60 cm long and about 1 cm in diameter, and after birth the distal portions of the umbilical arteries degenerate to form the medial umbilical ligaments.[1] In surgical simulation the cord is modelled where a trainee has to tell one congenital abdominal wall defect from another: omphalocele is a defect of the cord itself, in which the intestinal contents do not return to the abdominal cavity after physiological herniation, whereas gastroschisis is an incomplete closure of the abdominal wall, usually to the right of the umbilicus, exposing the fetal intestine — so on a gastroschisis model the cord has to read as separate from the herniated bowel.[2]
Things to Look Out For
- Placing the cord clamp too close to the viscera — in the published validation one expert marked the model down with the comment "The cord clamp seems to be too close to the viscera", and the authors list moving the clamp away from the viscera among the improvements planned for the next version of the model. The clamp should mark the cord, not crowd the herniated bowel.[2]
- Adding blood around the defect — another expert commented that "The presence of blood could be confusing in the possibility of bowel damage", and the authors list removing the blood makeup among their planned improvements. Blood applied near the cord and defect invites the trainee to read an injury that is not part of the diagnosis being taught.[2]
- Letting the cord read as continuous with the bowel — the authors set out as a design prerequisite that the model must demonstrate the umbilicus, the defect, the exposed abdominal loop and the differences between gastroschisis and omphalocele. A cord that is not clearly separate from the herniated loops removes one of the signs the trainee is being taught to distinguish.[2]
Related Structures
- Umbilicus — the navel, marking the site where the cord attached; a distinct tissue from the cord itself
- Abdominal Wall — the wall whose incomplete closure produces gastroschisis
- Bowel — the herniated intestinal contents the cord must stay visibly separate from on the gastroschisis model
References
[edit source]- ↑ Brahmandam G, Lipsett BJ. "Anatomy, Abdomen and Pelvis: Umbilical Cord." StatPearls. StatPearls Publishing, Treasure Island (FL). NCBI Bookshelf NBK557389.
- ↑ 2.0 2.1 2.2 2.3 Medeiros GA, Gualberto IJN, da Silva CHND, Diniz AMB, de Santana JBF, Volpe FP, Gadde R, Mazzo A, de Oliveira RC, Sbragia L. "Development of a low-cost congenital abdominal wall defect simulator (WALL-GO) for undergraduate medical education: a validation study." BMC Medical Education 2023;23(1):966. DOI: 10.1186/s12909-023-04929-3. PMID: 38102605. PMC10724958. Licensed CC BY 4.0.
Overview
[edit source]The umbilical cord enters this collection through congenital abdominal wall defect training, where a builder needs a cord that reads clearly as separate from herniated bowel. Medeiros et al. (2023) form it on a 40 cm vinyl doll and mark it with an umbilical cord clamp. The two-model WALL-GO build — one gastroschisis manikin and one omphalocele manikin — cost US$42 in total, about US$21 per manikin, from materials the authors state were all available in the local market in Brazil. The finished models are used by visual inspection rather than by handling, so the cord's job is to be seen and told apart, not to be cut or tied.
Synonyms
[edit source]- Medical terms: Umbilical cord
- Parts: Umbilical arteries, umbilical vein, Wharton's jelly
- Common names: Cord
- Regional names: Cordón umbilical (ES), Cordon ombilical (FR), Cordão umbilical (PT), Nabelschnur (DE)
Clinical Context for Simulation
Congenital abdominal wall defects are the setting in which the cord matters for training. Medeiros et al. (2023) report an incidence of approximately one gastroschisis per 2,000 live births and almost one omphalocele per 4,000, and note that in most cases the two are distinguished visually on inspection. The cord is one of the distinguishing signs: omphalocele is a defect of the cord itself, with the viscera at the umbilicus covered by a membranous sac, while in gastroschisis the wall fails to close to the right of the umbilicus, the bowel is exposed and uncovered, and the cord remains separate from it. The authors set out, as design prerequisites for their simulator, that it must represent a newborn and demonstrate the presence of the umbilicus, the abdominal wall defect, the exposed abdominal loop, and the differences between the two conditions. Their model was assessed by 15 experts and 90 medical students in their first to fifth year, returning content validity indexes of 94.6% and 96.4% respectively.