Second Pharyngeal Arch

**Semantic type:** Embryonic Structure

**Definition:** The second of the six pharyngeal arch pairs, which are formed of mesodermal outpouchings and located on either side of the developing pharynx; structures formed from the second arch include the stapes, the temporal styloid process, the stylohyoid ligament, the lesser cornu of the hyoid bone, and multiple muscle groups, including the muscles of facial expression.

**Synonyms:** - Hyoid Arch