Innervation of male pelvis (overview)

The innervation of the male pelvis is a complex network of nerves that ensures proper motor control, sensory perception, and autonomic regulation of the pelvic structures and organs. At the foundation of this system are two nervous plexuses - lumbar plexus (Read more!) and sacral plexus (Read more!), which provide most of the nerve supply to the pelvic walls, pelvic floor muscles, perineum, and portions of the lower limbs.

These plexuses are formed by the ventral rami of the first lumbar to the fourth sacral spinal nerves (L1 - S4). All these nerves branch extensively to create both anterior and posterior divisions of the mentioned plexuses that contribute to motor, sensory, and autonomic functions.

Additionally, one more plexus plays an essential role in providing the motor and sensory supply to the structures of the pelvic floor and adjacent areas. It is the coccygeal plexus (Read more!), which is formed by the ventral rami of the fourth and fifth sacral nerves (S4 - S5) and the coccygeal nerve (Co).

A critical connection between the lumbar and sacral plexuses is the lumbosacral trunk (Read more!), formed by the ventral rami of part of the L4 nerve and the entire L5 nerve. This trunk crosses the sacroiliac joint and joins the sacral plexus, serving as a bridge between the lumbar and sacral regions. Through these connections, the lumbosacral trunk ensures coordinated innervation of the pelvis and lower limb, enabling movements such as hip extension and rotation, as well as supporting functions of the pelvic floor.

In addition to voluntary motor control, the nerves arising from these plexuses play an essential role in the autonomic regulation of pelvic viscera. The sacral plexus contributes to the formation of the pelvic splanchnic nerves (S2 - S4), which provide parasympathetic innervation to pelvic organs, including the urinary bladder, intestines, and reproductive system organs. Together, the lumbar, sacral, and coccygeal plexuses, connected by the lumbosacral trunk, form an integrated network that is vital for both somatic and autonomic functions on the male pelvis.