Discharge of Urine by The Navel, or Persistent Urachus.

Discharge of Urine by The Navel, or Persistent Urachus.

This occurs only in the newborn, and consists in the nonclosure of the natural channel (urachus), through which the urine is discharged into the outer water bag (allantois) in fetal life. At that early stage of the animal existence the bladder resembles a long tube, which is prolonged through the navel string and opens into the outermost of the two water bags in which the fetus floats. In this way the urine is prevented from entering the inner water bag (amnion), where it would mingle with the liquids, bathing the skin of the fetus and cause irritation. At birth this channel closes up, and the urine takes the course normal to extra-uterine life. Imperfect closure is more frequent in males than in females, because of the great length and small caliber of the male urethra and its consequent tendency to obstruction. In the female there may be a discharge of a few drops only at a time, while in the male the urine will be expelled in strong jets coincidently with the contractions of the bladder and walls of the abdomen.