Pharyngeal Arches v3 (updates in red) Each pharyngeal arch contains: (1) a skeletal component (early on, a cartilaginous rod); (2) a muscular component; (3) an aortic arch; and (4) a nerve. Pharyngeal Arch Skeletal Component Muscles Aortic Arch Nerve First P. Arch Meckel's cartilage (malleus, incus) mm. of mastication, ant. belly 1st aortic arch Trigeminal N “mandibular maxillary prominence (maxilla*) of digastric, mylohyoid, tensor (maxillary AA) V2 and V3 arch” mandibular prominence (mandible*) tympani, tensor veli palatini Second P. Arch Reichert's cartilage (stapes, styloid mm. of facial expression, 2nd aortic arch Facial N “hyoid arch” process, stylohyoid lig.) buccinator, platysma, stapedius, (stapedial AA) VII hyoid, lesser cornua & superior body stylohyoid, post. belly of digastric Third P. Arch hyoid, greater cornua & inferior body stylopharyngeus 3rd aortic arch Glossophar. N (common carotids) IX Fourth P. Arch thyroid cartilage, epiglottic cartilage† cricothyroid, all intrinsic mm. 4th aortic arch Vagus: SLN of soft palate except tensor (aorta, R subclav.‡) & pharyn. plex. veli palatini X Fifth P. Arch - no derivatives - Sixth P. Arch cricoid, arytenoid, and corniculate all intrinsic mm. of larynx 6th aortic arch Vagus: RLN cartilages† except cricothyroid (pulmonary AA, X ductus arteriosus) * The maxillary and mandibular prominences are modeled on the first arch, but the bones develop separately from the first arch cartilage. † According to some sources the corniculate and cuneiform cartilages are derived from the 4th arch, not the 6th; I may revise this later on. ‡ Right subclavian A is derived from 4th aortic arch, right dorsal aorta, and right 7th intersegmental A; left subclavian A is derived from left 7th intersegmental A only, with no aortic arch component. .