Chapter 21, Problem 21.5.3AYLO

Summary Introduction

To determine:

The origin of the single dorsal aorta and intersegmental arteries.

Introduction:

Five pairs of pharyngeal arches are formed by the embryo in 4 to 5 weeks. As these arches develop, the aortic sac appears. Then, an artery appears from each side of the sac, loops around the arch, and then ends at the dorsal aorta. This loop is termed as aortic arch I and aortic arches (II to VI) arise from the pharyngeal pouches.