1. The metathoracic accessory pulsatory organ is very small and has no direct channels connecting the dorsal vessel, but there is a pulsating membrane without muscle.
后胸辅搏动器很小，与背血管无直接通道，具有一个没有肌肉的搏动膜。
youdao
2. The metathoracic accessory pulsatory organ is very small and has no direct channels connecting the dorsal vessel, but there is a pulsating membrane without muscle.
