Onuf's nucleus

Onuf's nucleus is a group of neurons located in the sacral spinal cord that innervate the pelvic floor muscles. It is named after the Polish-American neurologist Bronislaw Onufrowicz, who first described it in 1899.

Etymology

The term "Onuf's nucleus" is derived from the name of Bronislaw Onufrowicz, a Polish-American neurologist who first described this group of neurons in 1899.

Anatomy

Onuf's nucleus is located in the anterior horn of the sacral spinal cord, specifically in the second, third, and fourth sacral segments (S2-S4). It is composed of motor neurons that innervate the muscles of the pelvic floor, including the external urethral sphincter, external anal sphincter, and bulbospongiosus muscle.

Function

The neurons in Onuf's nucleus are responsible for voluntary control of micturition and defecation. They also play a role in sexual function, particularly in males, by controlling the muscles involved in ejaculation.

Clinical significance

Damage to Onuf's nucleus can result in a variety of disorders, including urinary incontinence, fecal incontinence, and sexual dysfunction. It has been implicated in several neurodegenerative diseases, such as Parkinson's disease, multiple system atrophy, and amyotrophic lateral sclerosis (ALS).

See also

• Neuron
• Sacral spinal cord
• Pelvic floor

References

Onuf's nucleus Resources
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