Pedal across the Golden Gate Bridge on this scenic San Francisco bike tour, a family-friendly adventure bringing you up close to the cityâs most famous ... Read more. Location: San Francisco, California. Duration: Tour lasts between 2.5 and 3 hours; bike rental valid for 24 hours.
posterior median fissure. 1. a shallow vertical groove in the closed part of the medulla oblongata, continuous with the posterior median fissure of the spinal cord. 2. a shallow vertical groove dividing the spinal cord throughout its length in the midline posteriorly; called also posterior median sulcus.
Anal fissures are caused by trauma to the anus and anal canal. The cause of the trauma usually is a bowel movement, and many people can remember the exact bowel movement during which their pain began. The fissure may be caused by a hard stool or repeated episodes of diarrhea.nal fissures are caused by trauma to the anus and anal canal. The cause of the trauma usually is a bowel movement, and many people can remember the exact bowel movement during which their pain began. The fissure may be caused by a hard stool or repeated episodes of diarrhea.