The navel (clinically known as the umbilicus, colloquially known as the belly button) is a scar on the abdomen at the attachment site of the umbilical cord. All placental mammals have a navel, and it is quite conspicuous in humans. Other animals' navels tend to be smoother and flatter, often nothing more than a thin line, and are often obscured by fur as well. The umbilicus is a prominent mark on the abdomen, with its position being relatively consistent amongst humans. The skin around the waist at the level of the umbilicus is supplied by the tenth thoracic spinal nerve (T10 dermatome). The umbilicus itself typically lies at a vertical level corresponding to the junction between the L3 and L4 vertebrae, with a normal variation among people between the L3 and L5 vertebrae.
Contributions by 126.96.36.199, Donald Albury, and Englishmane.