A child is born with malformed incus and malleus and underdeveloped muscles of mastication. A defect in the development of which pharyngeal arch is responsible?

• A Fourth pharyngeal arch
• B Second pharyngeal arch
• C Third pharyngeal arch
• D First pharyngeal arch ✓

Explanation

The first pharyngeal arch gives rise to the muscles of mastication, mylohyoid, tensor tympani, and the malleus and incus via Meckel cartilage. The second arch forms the stapes, styloid process, and muscles of facial expression. The third arch forms the stylopharyngeus muscle and the greater horn of the hyoid bone. The fourth and sixth arches contribute to the laryngeal cartilages and muscles.

Reference: Gray's Anatomy for Students, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.