Which of the following aoic arches regress during development:
High-Yield Explanation
The aoic sac contributes a branch to each new arch as it forms, giving rise to a total of five pairs of aeries. (The fifth arch either never forms or forms incompletely and then regresses. Consequently, the five arches are numbered I, II, III, IV, and VI Ref: Langman's embryology 11th edition Chapter 12.