Which pharyngeal arch forms the lesser horn of the hyoid bone and the upper portion of the body of the hyoid bone?

Which pharyngeal arch forms the lesser horn of the hyoid bone and the upper portion of the body of the hyoid bone?

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

Answer: (B)

The hyoid bone has parts that come from different pharyngeal arches during development. The lesser horn and the upper portion of the body originate from Reichert’s cartilage of the second pharyngeal arch. This same arch contributes to other structures such as the stapes and styloid process. The greater horn and the lower part of the body come from the third pharyngeal arch. So the feature described—lesser horn plus the upper body—fits with the second arch.

The hyoid bone has parts that come from different pharyngeal arches during development. The lesser horn and the upper portion of the body originate from Reichert’s cartilage of the second pharyngeal arch. This same arch contributes to other structures such as the stapes and styloid process. The greater horn and the lower part of the body come from the third pharyngeal arch. So the feature described—lesser horn plus the upper body—fits with the second arch.