鳃器的发生 鳃器:是鳃弓、鳃沟、咽囊和鳃膜的总称 Cranial neuropore 1 st and 2nd Otic placode Pharyngeal pharyngeal Pharyngeal clefts Pericardial arches arches bulge Cut edge Lens of amnion placode Heart bud Vitelline duct bulge Umbilical Connecting cord Pericardial stalk- swelling A Caudal B neuropore一、鳃器的发生 鳃器：是鳃弓、鳃沟、咽囊和鳃膜的总称