In a highly selective vagotomy, the vagal supply is severed to –
**Core Concept**
A highly selective vagotomy is a surgical procedure that aims to reduce acid secretion in the stomach by selectively severing the vagal fibers that innervate the parietal cell mass, while preserving the vagal fibers that innervate the antrum and pylorus. This allows for the preservation of gastric motility and emptying.
**Why the Correct Answer is Right**
The vagus nerve, also known as the tenth cranial nerve, has both parasympathetic and sympathetic fibers. The parasympathetic fibers, specifically the vagal fibers, stimulate the parietal cells to secrete gastric acid. In a highly selective vagotomy, the vagal fibers that innervate the parietal cell mass are selectively severed, thereby reducing acid secretion. This is achieved by identifying the specific branches of the vagus nerve that supply the parietal cells and selectively ligating or cutting them.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because a highly selective vagotomy specifically targets the vagal fibers that innervate the parietal cells, not the pyloric sphincter.
**Option B:** This option is incorrect because a highly selective vagotomy preserves the vagal fibers that innervate the antrum and pylorus, not the pyloric sphincter.
**Option C:** This option is incorrect because a highly selective vagotomy does not involve the resection of the stomach, but rather selective severing of vagal fibers.
**Clinical Pearl / High-Yield Fact**
The key to a successful highly selective vagotomy is to identify the specific branches of the vagus nerve that supply the parietal cells and selectively sever them, thereby preserving gastric motility and emptying.
**Correct Answer:** C. The vagal supply to the pyloric sphincter is severed in a highly selective vagotomy.