Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
The sacral plexus is a network of nerve fibers located in the lower back, formed by the branching of the lower spinal nerves (L4-S4). This plexus innervates the pelvic region, buttocks, genitals, thighs, calves, and feet.
Related terms
Sciatic nerve: The largest and longest nerve in the human body, originating from the sacral plexus, and responsible for motor and sensory functions in the thigh, knee, calf, ankle, foot, and toes.
Lumbar plexus: A network of nerve fibers arising from the lumbar region of the spine (L1-L4), which provides motor and sensory nerves to the lower abdomen and parts of the legs.
Pudendal nerve: A nerve arising from the sacral plexus that supplies areas including the external genitalia and anal region with both sensory and motor fibers