The navel, commonly known as the belly button, is a common anatomical feature on the human abdomen. It appears as a small depression or protrusion on the skin, marking the former attachment point of the umbilical cord. This distinctive landmark serves as a central reference point on the body’s surface. Its appearance varies significantly among individuals in shape, size, and depth.
Anatomy Directly Behind the Navel
No single organ sits directly behind the navel; instead, this area consists of several tissue layers providing structural support and protection to the abdominal cavity. Moving inward from the skin, subcutaneous fat provides insulation and cushioning. Beneath this fatty layer are the abdominal muscles, specifically the rectus abdominis muscles, which run vertically along the front of the abdomen.
These muscles are joined in the midline by the linea alba, a dense fibrous band particularly narrow and strong at the navel. Deeper lies the peritoneum, a thin membrane lining the inner wall of the abdominal cavity and covering most abdominal organs. Fibrous remnants of the umbilical cord, such as the round ligament of the liver and the median umbilical ligament, are also present in this region as non-functional structures in adults.
Major Organs in the Abdominal Cavity
While no single organ sits directly behind the navel, many major organs are located within the broader abdominal cavity, often in its general vicinity. The liver, a large organ for detoxification and metabolism, occupies the upper right abdomen, extending partially above and to the right of the navel. The stomach, for initial food digestion, is positioned above and slightly to the left of the navel.
The small intestine, a coiled tube where most nutrient absorption occurs, fills a central portion of the abdomen, including the area surrounding the navel. The large intestine, or colon, surrounds the small intestine, framing the abdominal cavity. Parts of it pass above, to the sides, and below the navel as it processes waste.
Deeper in the upper abdomen, behind the stomach, lies the pancreas, which produces digestive enzymes and hormones like insulin. The spleen, involved in filtering blood and immune function, is in the upper left abdomen. The kidneys, which filter waste from the blood to produce urine, are towards the back of the abdominal cavity, on either side of the spine.
How the Navel Forms
The navel forms during fetal development. It originates from the umbilical cord, a tube-like structure connecting the fetus to the placenta. This cord serves as the fetus’s lifeline, containing two umbilical arteries that carry deoxygenated blood and waste away, and one umbilical vein that delivers oxygenated blood and nutrients.
Beyond blood vessels, the umbilical cord also encases remnants of other fetal structures, including the vitelline duct and the urachus. After birth, the umbilical cord is clamped and cut, severing the connection to the placenta. The remaining stump gradually dries and detaches within one to three weeks. This natural process leaves the characteristic scar tissue that forms the navel.