The umbilical ring is a dense fibrous ring surrounding the umbilicus at birth. At about the sixth week of

embryological development Prenatal development () includes the development of the embryo and of the fetus during a viviparous animal's gestation. Prenatal development starts with fertilization, in the germinal stage of embryonic development, and continues in fetal deve ...

, the

midgut The midgut is the portion of the embryo from which most of the intestines develop. After it bends around the superior mesenteric artery, it is called the "midgut loop". It comprises the portion of the alimentary canal from the end of the foregut ...

herniates through the umbilical ring; six weeks later it returns to the abdominal cavity and rotates around the

superior mesenteric artery In human anatomy, the superior mesenteric artery (SMA) is an artery which arises from the anterior surface of the abdominal aorta, just inferior to the origin of the celiac trunk, and supplies blood to the intestine from the lower part of the ...

. Dense embryonic

connective tissue Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tiss ...

encircles the attachment of the

umbilical cord In placental mammals, the umbilical cord (also called the navel string, birth cord or ''funiculus umbilicalis'') is a conduit between the developing embryo or fetus and the placenta. During prenatal development, the umbilical cord is physiologic ...

. It forms an umbilical ring of

mesoderm The mesoderm is the middle layer of the three germ layers that develops during gastrulation in the very early development of the embryo of most animals. The outer layer is the ectoderm, and the inner layer is the endoderm.Langman's Medical E ...

al condensation surrounding the coelomic portal, and is present in the 16 mm. embryo, but more emphatically so in the 23 mm. embryo. The

compact tissue A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, and ...

first appears in the stalk mesoderm, situated superficial to the allantoic vessels. Cranially it lies ventral to the umbilical vein and on each side extends into the tissue of the lateral pillars of the cord bounding the coelom. When the myotomic downgrowths reach the ventral aspect, their anterior portions (i.e. the sheaths of the recti muscles) become continuous with the tissue of the umbilical ring.

Umbilical hernia

When the umbilical ring has failed to close during the gestation (pregnancy) which results in a central defect in the lineal alba. Umbilical hernias are smaller than one centimeter in size that it is present at birth but will only close in four to five years of life. In some cases, hernias don't need any surgical repair but when it is larger in size that protrusion is blighting to the parent and the child, it would require to get an early surgical repair. It is more common in women with increased intra-abdominal pressure during pregnancy.

References

Abdomen {{developmental-biology-stub