The urachus is a fibrous cord connecting the urinary bladder to the umbilicus (belly button).
Fetal Development and the Urachus
During fetal development, the urachus is initially the allantoic stalk. This structure plays a role in the developing urinary system. As the fetus develops, the urachus typically closes off and becomes a ligament. This ligament, also known as the median umbilical ligament, persists throughout life.
Clinical Significance
While usually a vestigial structure (meaning it has lost its original function), problems can arise with the urachus. These can include:
- Urachal cysts: These are fluid-filled sacs that can form within the urachus.
- Urachal sinuses: These are openings or tracts that may connect the bladder to the umbilicus.
- Urachal fistulas: These are abnormal connections that create a pathway between the bladder and the umbilicus, allowing urine to leak out through the navel.
These conditions usually require medical attention. Symptoms may include discharge from the umbilicus or abdominal discomfort.
(YOO-rah-kus) A fibrous cord that connects the urinary bladder to the umbilicus (navel). The urachus is formed as the allantoic stalk during fetal development and lasts through life. Also called median umbilical ligament.
