The inferior rectal artery supplies which structure?

• A. Anal canal
• B. Perineal muscles
• C. Scrotum
• D. Penile skin

Answer: (A)

The inferior rectal artery’s main territory is the lower anal region. It is a branch of the internal pudendal artery and supplies the lower part of the anal canal, as well as the surrounding perianal skin and the external anal sphincter. This distinguishes its distribution from other arteries in the area: the upper rectum is fed by the superior rectal artery (from the inferior mesenteric artery), while the middle rectal artery (from the internal iliac) supplies the mid-rectum. The scrotum and penile skin have separate arterial sources (such as branches of the internal pudendal and external pudendal arteries, and dorsal arteries of the penis), not the inferior rectal artery. Therefore, the structure supplied by the inferior rectal artery is the anal canal.