In Carcinoma head of pancreas, Nausea & vomiting is due to:
**Core Concept**
Carcinoma of the head of the pancreas can cause nausea and vomiting due to the mechanical obstruction of the duodenum and the release of various peptides and hormones by the tumor. The tumor can also cause gastric outlet obstruction, leading to vomiting.
**Why the Correct Answer is Right**
The correct answer is related to the mechanical obstruction caused by the tumor. The head of the pancreas is located near the duodenum, and a tumor in this area can cause obstruction of the duodenum, leading to nausea and vomiting. The obstruction can be due to the direct invasion of the tumor into the duodenum or due to the compression of the duodenum by the tumor. This is a classic mechanism of vomiting in carcinoma of the head of the pancreas.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the pathophysiology of nausea and vomiting in carcinoma of the head of the pancreas.
**Option B:** While gastrinomas can cause Zollinger-Ellison syndrome, which can lead to severe peptic ulcer disease, they are not typically associated with nausea and vomiting in carcinoma of the head of the pancreas.
**Option C:** This option is not a known cause of nausea and vomiting in carcinoma of the head of the pancreas.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that carcinoma of the head of the pancreas can cause mechanical obstruction of the duodenum, leading to nausea and vomiting. This is a classic presentation of this condition, and clinicians should consider this diagnosis in patients with a history of pancreatitis or a known pancreatic mass.
**Correct Answer: C. Mechanical obstruction of the duodenum.**