羊膜中的心脏和主动脉弓动脉形成双循环,将含氧血液从心脏带到身体,将脱氧血液带到肺部。这些主要血管是在胚胎发育过程中由一系列成对的对称动脉形成的,这些动脉经历了复杂的重塑过程,在成人中形成了不对称的弓动脉。这些胚胎动脉形成于咽弓,它们是头部侧面对称的凸起。咽弓,和它们相关的动脉,在所有种类的脊椎动物中都有发现,但是数量各不相同,通常随着拱门的数量随着进化而减少。例如,颌骨脊椎动物有六对咽弓动脉,但羊膜,四足脊椎动物的进化枝,有五对。这导致了羊膜中每个咽弓动脉(1、2、3、4和6)的异常编号系统。我们,因此,建议将这些命名为反映血管的名称:下颌(第1个),舌骨(第二),颈动脉(第三),主动脉(第四)和肺(最尾)。异常的弓动脉形成或重塑导致危及生命的先天性心血管畸形,比如主动脉弓的中断,颈部动脉起源,和血管环。我们讨论了为什么所谓的第五弓动脉被错误地用于解释先天性心脏病变,更好地解释为异常的抵押渠道,或主动脉囊的重塑.
The heart and aortic arch arteries in amniotes form a double circulation, taking oxygenated blood from the heart to the body and deoxygenated blood to the lungs. These major vessels are formed in embryonic development from a series of paired and symmetrical arteries that undergo a complex remodelling process to form the asymmetric arch arteries in the adult. These embryonic arteries form in the pharyngeal arches, which are symmetrical bulges on the lateral surface of the head. The pharyngeal arches, and their associated arteries, are found in all classes of vertebrates, but the number varies, typically with the number of arches reducing through evolution. For example, jawed vertebrates have six pairs of pharyngeal arch arteries but amniotes, a clade of tetrapod vertebrates, have five pairs. This had led to the unusual numbering system attributed to each of the pharyngeal arch arteries in amniotes (1, 2, 3, 4, and 6). We, therefore, propose that these instead be given names to reflect the vessel: mandibular (1st), hyoid (2nd), carotid (3rd), aortic (4th) and pulmonary (most caudal). Aberrant arch artery formation or remodelling leads to life-threatening congenital cardiovascular malformations, such as interruption of the aortic arch, cervical origin of arteries, and vascular rings. We discuss why an alleged fifth arch artery has erroneously been used to interpret congenital cardiac lesions, which are better explained as abnormal collateral channels, or remodelling of the aortic sac.