Which pharyngeal arch contributes to the thyroid cartilage?

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

Answer: (B)

The laryngeal skeleton gets laid down from the pharyngeal arches, and the thyroid cartilage specifically forms from the ventral part of the fourth arch’s mesenchyme. As these arches contribute to different neck structures, the fourth arch provides the groundwork for the thyroid cartilage, with other laryngeal elements arising largely from the sixth arch. So the thyroid cartilage comes from the fourth arch.