The belly button, also known as the navel, is a universal human feature, a small indentation or protrusion on the abdomen. This unique mark serves as a lasting reminder of our earliest connection to our mother. While its presence is common, what lies beneath this scar and its journey to formation often sparks curiosity. Understanding its origins and internal connections provides insight into a remarkable aspect of human development.
The Journey from Cord to Belly Button
The belly button begins as the umbilical cord, a flexible tube that acts as a lifeline between a developing fetus and the placenta. This cord plays a vital role throughout pregnancy, acting as a two-way highway for essential substances. It actively transports oxygen and nutrient-rich blood from the placenta to the fetus. Simultaneously, it carries deoxygenated blood and waste products away from the fetus back to the placenta for removal by the mother’s body.
At birth, the umbilical cord is no longer needed because the baby can breathe and feed independently. Healthcare providers clamp and cut the cord, leaving a short stump attached to the baby’s abdomen. This procedure is painless for both the mother and the newborn as there are no nerve endings in the cord.
The remaining umbilical stump then undergoes a natural drying process. Over one to three weeks, it gradually changes color, shrivels, and dries out. This dried stump eventually detaches, revealing the healed scar that becomes the belly button.
The Internal Anatomy of the Navel
In adults, the belly button is primarily a surface scar and does not directly connect to any functional internal organs. However, the structures that once comprised the umbilical cord transform into fibrous remnants within the body. These transformed structures serve as anatomical landmarks.
The umbilical cord initially contained two umbilical arteries and a single umbilical vein. After birth, these blood vessels, no longer necessary for circulation, undergo a process of obliteration and become dense, cord-like ligaments.
The two umbilical arteries, which carried deoxygenated blood from the fetus, transform into the medial umbilical ligaments. These paired ligaments extend from the navel downwards to the bladder, offering it some support.
The single umbilical vein, responsible for delivering oxygenated blood and nutrients to the fetus, becomes the ligamentum teres hepatis, commonly known as the round ligament of the liver. This ligament extends from the belly button upwards to the liver, where it integrates into the falciform ligament.
Beyond these vessel remnants, the median umbilical ligament is a remnant of the urachus. This ligament connects the bladder to the umbilicus and also transforms into a fibrous cord after birth.