Contents of mesorectum are of except
**Core Concept**
The mesorectum is a fatty tissue enveloping the rectum, containing lymph nodes, blood vessels, and nerves. It plays a crucial role in the spread of rectal cancer. Understanding the contents of the mesorectum is essential for surgeons and oncologists to plan the surgical approach and lymph node dissection.
**Why the Correct Answer is Right**
The mesorectum contains lymph nodes, blood vessels, and nerves that surround the rectum. The lymph nodes within the mesorectum are the primary sites for metastasis in rectal cancer. The autonomic nerves, including the inferior hypogastric plexus, also reside within the mesorectum, which can be affected during rectal surgery. The fatty tissue provides a cushioning effect and facilitates the movement of the rectum.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the mesorectum is a compartment that encloses the rectum, and its contents include lymph nodes, blood vessels, and nerves, but not the rectal wall itself.
* **Option B:** This option is incorrect because the mesentery of the small intestine is a separate structure that suspends the small intestine, and it does not contain the rectum or its associated lymph nodes.
* **Option C:** This option is incorrect because the presacral fascia is a layer of connective tissue that lies anterior to the sacrum and posterior to the rectum, but it does not contain the contents of the mesorectum.
**Clinical Pearl / High-Yield Fact**
The mesorectum is a key anatomical structure that surgeons must identify and remove during rectal cancer surgery to minimize the risk of recurrence. The concept of "total mesorectal excision" (TME) has revolutionized the surgical approach to rectal cancer, with improved outcomes and reduced morbidity.
**Correct Answer:** A. The rectal wall itself is not a content of the mesorectum.