蝶骨为构成颅骨的29块骨骼之一，共一块。当从前方观察时，其形状如同蝴蝶，所以得名。蝶骨分为体、小翼、大翼和翼突四个部分。

蝶骨分为以下部分:

• 蝶骨体位于蝶骨中央，蝶骨体上有土耳其鞍、鞍背、前床突、后床突等构造，脑下垂体位于土耳其鞍上。
• 具有两对大翼及小翼
• 翼突由后方向前延伸

两个蝶甲位于蝶骨体的前后方

The sphenoid bone is an unpaired bone of the neurocranium. It is situated in the middle of the skull towards the front, in front of the temporal bone and the basilar part of the occipital bone. The sphenoid bone is one of the seven bones that articulate to form the orbit. Its shape somewhat resembles that of a butterfly or bat with its wings extended.