Question

Which one remains unaffected, if the vagus nerve is injured in humans?
a. Gastrointestinal movement
b. Tongue movements
c. Cardiac movement
d. Pancreatic activities

Answer 1

Hint: The vagus nerve can control many organs except few. They are associated with the movement of stomach, intestines, heart and other major internal organs of humans. The organs which are not directly involved with this nerve are not affected by its damage.

Complete answer:
> Option B, is correct, Vagus nerve is a mixed cranial nerve. It controls our gastrointestinal activities mainly of the gut and heart. The tongue movement in humans’ remains unaffected even if the vagus nerve is injured because tongue movement is controlled by another nerve namely, glossopharyngeal nerve, instead of the vagus nerve.

> Option A, gastrointestinal movement is an incorrect answer, as any injury to the vagus nerve will surely affect its movement. The parasympathetic innervation to the stomach, small intestine and proximal colon is supplied and carried out by the vagus nerve.

> Option C, Cardiac Movement will be affected in case of any vagus nerve damage because the heart is innervated by vagal and sympathetic fibers in our body. The right vagus nerve primarily innervates the SA node and the left vagus innervates the AV node respectively. Hence, this option is incorrect.

> Option D, Activation of the vagus nerve directly affects pancreatic exocrine and endocrine secretion. So, the Pancreatic Movement is the incorrect answer.

Hence, The correct answer is option (B).

Additional information:
The vagus nerve, also called pneumogastric nerve, is the tenth cranial nerve or CN X. They connect and interface with the parasympathetic control of the heart, lungs, and digestive tract. The vagus nerves are the longest nerve of the autonomic nervous system in the human body, comprising sensory and motor fibers. The vagus nerve supplies motor parasympathetic fibers to all the organs from the neck down to the second segment of the transverse colon except the adrenal glands. This nerve is responsible for movement of heart rate, gastrointestinal peristalsis, sweating, and quite a few muscle movements in the mouth, including speech.

Note: The vagus nerve can be damaged by certain diseases like diabetes, or by any surgery to the stomach or small intestine. If the vagus nerve is damaged, nausea, bloating, diarrhea and gastroparesis may occur. A damaged vagus nerve cannot send signals to the stomach, causing the food to remain in your stomach longer rather than moving into the small intestine.