What is the definition or description of: cauda equina?

Tail of the horse: Spinal cord ends at upper lumbar spine (l1-2 level) and become a bundle of nerve roots, which look like horse tail. It passes bony tube inside the lumbar vertebrae while sending out nerve roots at each spine levels. You can easily visualize the anatomy on-line if you access google image.

Horses tail!: The bottom part of your spinal cord fans out into a number of nerve endings and looks like a horses tail. It is a unique area that if injured can lead to loss of control of bowel or bladder movement and decreased sensation about your groin. It is an orthopaedic emergency that must be identified and treated early and quickly.