Inferior rectal aery is a branch of?
**Core Concept**
The inferior rectal artery is a branch of a major artery supplying the pelvic region, playing a crucial role in the blood supply to the rectum and anal region. This artery is essential for maintaining the integrity of the anal mucosa and surrounding tissues.
**Why the Correct Answer is Right**
The inferior rectal artery arises from the **internal iliac artery**, a major branch of the common iliac artery. This artery supplies blood to the pelvic floor muscles, including the external anal sphincter, and the anal canal. The internal iliac artery is a key supplier of blood to the pelvic viscera and muscles.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the inferior rectal artery does not arise from the common iliac artery, which is its parent vessel but not the direct origin.
**Option B:** This option is incorrect because the inferior rectal artery does not arise from the superior rectal artery, which is a branch of the inferior mesenteric artery.
**Option C:** This option is incorrect because the inferior rectal artery does not arise from the pudendal artery, which is a branch of the internal iliac artery but not the direct origin of the inferior rectal artery.
**Clinical Pearl / High-Yield Fact**
The inferior rectal artery is a branch of the internal iliac artery, and its ligation can lead to ischemia of the anal mucosa and surrounding tissues, potentially resulting in anal incontinence.
**Correct Answer: D. Internal iliac artery.