Pharyngeal Arches

Question 1

1st arch

Answer 1

Innervated by the trigeminal(5th) nerve which innervates the muscles of mastication . , therefore the muscles of mastication , mylohyoid , oral jaw (maxilla , mandible ) derived from the 1st arch . In embryo , Intially separates mouth from pericardium

Question 2

2nd arch

Answer 2

Innervated by the facial nerve which innervates muscles of facial expression :buccinator . Hyoid bone and features for jaw support derived from this .

Question 3

3rd arch

Answer 3

Innervated by the glossopharyngeal nerve , which innervates single skeletal muscle/stylopharygeus muscle - involveved in elevating the pharynx in swallowing

Question 4

4th Arch

Answer 4

Innervated by the vagus nerve , 4th arch gives rise to all muscles or palate /pharynx . Cricothyroid muscle of larynx also innervated and derived from 4th arch . Also gives rise to thyroid /epiglottic cartilage .

Question 5

6th Arch

Answer 5

Innervated by the vagus nerve’s recurrent branch . Laryngeal muscles form from the 4th arch . All other laryngeal cartilages originate from here