Question

Which muscle is derived from the third pharyngeal arch?

• A. Tensor tympani
• B. Stylopharyngeus
• C. Cricothyroid
• D. None

Hint:

Match the arch to its nerve - the third arch follows the glossopharyngeal nerve.

Answer 1

The Correct Option is B

Step 1: Each pharyngeal (branchial) arch gives rise to specific muscles supplied by the nerve of that arch.

Step 2: The third pharyngeal arch is supplied by the glossopharyngeal nerve, and its only muscular derivative is the stylopharyngeus. This fits, since stylopharyngeus is innervated by the glossopharyngeal nerve.

Step 3: Looking at the distractors, tensor tympani is a first arch muscle (supplied by the mandibular nerve), and cricothyroid is a fourth arch muscle (supplied by the external laryngeal branch of the vagus).

Step 4: Hence stylopharyngeus is the correct third arch muscle.