Inferior Rectal Nerve - Podcast Version 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The inferior rectal nerve (inferior anal nerve, inferior haemorrhoidal nerve) is a nerve of the perineal region. It supplies motor innervation to the external anal sphincter and sensation to the lower anal canal and perianal skin. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Course The inferior rectal nerve arises from the pudendal nerve within the pudendal canal. It passes medially, crossing the medial wall of the pudendal canal and the ischioanal fossa – accompanied by the inferior rectal artery and vein. At the anal canal, the inferior rectal nerve terminates as motor fibres to the external anal sphincter, as well as sensory fibres to the anal canal and perianal skin. By TeachMeSeries Ltd (2026) Fig 1The inferior rectal nerve arises from the pudendal nerve within the pudendal canal. Motor Supply The inferior rectal nerve supplies somatic motor fibres to the external anal sphincter. By TeachMeSeries Ltd (2026) Fig 2- The inferior rectal nerve supplies somatic motor innervation to the external anal sphincter. Sensory Supply The inferior rectal neve supplies sensation to the lower half of the anal canal and the perianal skin. In females, it may also contribute to the innervation of the lower vaginal wall. Frequent questions What is the function of the inferior rectal nerve? The inferior rectal nerve provides motor innervation to the external anal sphincter and sensory innervation to the lower anal canal and perianal skin. This dual role is essential for both voluntary control of defecation and sensation in the perianal area. Where does the inferior rectal nerve originate? The inferior rectal nerve originates from the pudendal nerve within the pudendal canal. It travels medially, crossing the medial wall of the canal and the ischioanal fossa alongside the inferior rectal artery and vein. What structures does the inferior rectal nerve innervate? The inferior rectal nerve innervates the external anal sphincter with motor fibres and provides sensory innervation to the lower half of the anal canal and perianal skin. In females, it may also supply the lower vaginal wall. How does the inferior rectal nerve contribute to anal function? The inferior rectal nerve is crucial for anal function as it supplies motor fibres to the external anal sphincter, allowing for voluntary control during defecation. Additionally, it provides sensory feedback from the anal canal and surrounding skin. What is the clinical significance of the inferior rectal nerve? Understanding the inferior rectal nerve is important in clinical practice, particularly in surgeries involving the perineal region, as damage to this nerve can lead to incontinence or loss of sensation in the anal area. Its role in innervating the external anal sphincter makes it significant in conditions affecting bowel control. Rate This Article