endocranial

Endocranial is an anatomical term that describes structures or contents within the skull. It most commonly refers to the endocranium, the interior of the skull that houses the brain and related structures, collectively known as the endocranial cavity. The cavity is formed by the neurocranium bones and is lined by the meninges, with cerebrospinal fluid filling portions of the space. It contains the brain, the pituitary gland in the sella turcica, cranial nerves as they exit through foramina, and the arterial and venous vessels that supply the brain.

In comparative anatomy and paleontology, the term is also used for endocasts, natural or cast impressions of the inner skull surface. Endocasts preserve external features such as sulci impressions or overall brain size and shape and are used to infer neural organization in extinct or ancient species, though they do not capture soft tissue detail and may be distorted by preservation.

During embryonic development, the endocranial cavity forms around the developing brain, primarily from mesenchymal tissue that differentiates into the neurocranium, including the calvaria and skull base. The term can also describe inner-skulled structures in different vertebrates, emphasizing their location inside the cranial cavity.