Question

Which of the following is the tenth cranial nerve?
A. Pneumogastric
B. Glossopharyngeal
C. Trochlear
D. Trigeminal

Answer 1

Hint: The tenth cranial nerves are a group of nerves that start in the brain and provide motor and sensory functions to the head and neck. Each cranial nerve has its unique anatomical characteristics and functions.

Complete step by step answer: Pneumogastric nerve is commonly known as vagus. It is the 10th cranial nerve present in the skull. This nerve delivers nerves to the pharynx, oesophagus, bronchi, larynx, trachea, stomach and liver. Similar to the glossopharyngeal nerve, the vagus stimulates functions of swallowing and also sends and transmits signals to the autonomous nervous system of the brain. These signals help to regulate the activation and control of stress levels. Vagus also sends signals to the sympathetic system directly. The vagus nerve performs several functions including, motor, sensory, and parasympathetic functions. The pneumogastric nerve is the longest cranial nerve. It starts from the medulla and extends all the way to the abdomen. Vagus nerve is used by doctors for stimulation therapy and for the treatment of various conditions such as epilepsy, depression, and anxiety etc.
Out of the options:
i. Glossopharyngeal: It is the 9th cranial nerve.
ii. Trochlear: It is the 4th cranial nerve.
iii. Trigeminal: It is the 5th cranial nerve.
Hence, the correct answer is option A.

Additional information: The following are the functions of the cranial nerves:
a. The sensory cranial nerves assist in seeing, smelling and hearing.
b. The motor cranial nerves assists in the control of muscle movements on the head and neck region.
Each cranial nerve is named in accordance with its function and is assigned a number according to the region it is located in the brain.

Note: The trochlear nerve is the fourth cranial. It is also involved in eye movement. Both the trochlear nerve and the oculomotor nerve originate in the midbrain. The function of the trochlear nerve is to power the contralateral superior oblique muscles which allow the eye to point downward and inward.