颈内动脉发源于第三主动脉弓和背主动脉。到胎儿生长第五周时,形成了一个明显的弯曲,源自弓与主动脉以锐角相连处。当背主动脉根部下降至胸腔时动脉展开,最后至第二个月时在颈部呈直线走行。Kelly推测动脉不能充分展开或移位是由于背主动脉弓生长相对较大,导致颈动脉先天性弯曲。此弯曲常越过舌咽神经,且使颈动脉靠近扁桃体被 Internal carotid artery originated in the third aortic arch and dorsal aorta. By the fifth week of fetal growth, a significant curve results, resulting from the bow and the aorta connected at an acute angle. The artery unfolds when the dorsal aortic root descends to the thorax and finally runs straight in the neck until the second month. Kelly speculated that the inability of the artery to fully expand or shift was due to the relatively large growth of the dorsal aortic arch, leading to congenital carotid artery curvature. This curvature often passes over the glossopharyngeal nerve and brings the carotid artery closer to the tonsil