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]
Materials
| Material | Visual | Tactile | Simulator | Notes |
|---|---|---|---|---|
| Not specified in source | Abdominal Wall Defect Simulator (Medeiros) | The source states the team "sought valuable components for elaborating the umbilical cord, separated from the bowels in GS", and Figures 3 and 4 show a clamped cord on both mannequins. Table 2 lists the nine materials with sizes and prices but assigns a purpose to none, so which material forms the cord is not stated. An umbilical cord clamp (US$1) marks it.[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 2.4 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.