Sacral spinal nerve 2

The sacral spinal nerve 2, also known as S2, is one of the five pairs of sacral nerves in the human body. These nerves are part of the peripheral nervous system and play a crucial role in the innervation of the lower limbs and pelvic organs.

Anatomy

The sacral spinal nerve 2 emerges from the spinal cord at the level of the second sacral vertebra. It exits the vertebral column through the sacral foramina, which are openings in the sacrum, a large, triangular bone at the base of the spine.

The spinal cord with spinal nerves.

Function

The S2 nerve contributes to the sacral plexus, a network of nerves that supplies the skin and muscles of the pelvis and lower limb. Specifically, S2 is involved in the innervation of the gluteal region, the perineum, and parts of the lower limb.

The sacral spinal nerve 2 also plays a role in the autonomic nervous system, particularly in the parasympathetic nervous system. It helps control functions such as bladder and bowel movements, and sexual function.

Clinical Significance

Damage to the sacral spinal nerve 2 can result in a variety of symptoms, depending on the extent and location of the injury. Common symptoms include:

• Loss of sensation or motor function in the areas innervated by S2.
• Bladder and bowel dysfunction.
• Sexual dysfunction.

Conditions such as cauda equina syndrome can affect the sacral nerves, including S2, leading to severe neurological deficits.

Also see

• Sacral spinal nerve 1
• Sacral spinal nerve 3
• Lumbosacral plexus
• Cauda equina

References

• Gray's Anatomy for Students, 3rd Edition.
• Netter's Atlas of Human Anatomy, 7th Edition.