Braincase

Neurocranium
Neurocranium
Base of skull
Latin Neurocranium
Gray's subject #30 128
TA Template:TA98
FMA Template:FMA

In mammals, the neurocranium, braincase, or brainpan [1] (also spelled brain-pan[2]) is the back part of the skull and houses the brain. In front of it is the interorbital region.

In humans, the neurocranium is (also) the upper portion of the skull. The other, lower part of the skull is the viscerocranium.

Evolutionarily, the human neurocranium has turned from being (just) the back part to (also) being the upper part, because during the evolutionary expansion of the brain, the neurocranium has overgrown the viscerocranium. The upper-frontmost part of the cranium also houses the evolutionarily newest part of the human brain, the frontal lobes.

The term "cranium" can be ambiguous in that it can refer to the neurocranium, or the whole skull, meaning the neurocranium and the facial skeleton.

Structure

The size of the braincase is variable among mammals. The roof may contain ridges such as the temporal crests. Below the braincase is a complex of foramina (openings) and bones, including the foramen magnum which houses the neural spine. The auditory bullae, located in the same region, aid in hearing.[3]

The neurocranium is formed by the endocranium, the lower portions of the cranial vault, and the skull roof. These are not fused in fishes, and a proper neurocranium is only found in land vertebrates.

Human neurocranial bones

In humans, the neurocranium is usually considered to include the following eight bones:

The ossicles (three on each side) are usually not included when enumerating the bones of the neurocranium.[5] There may variably also be extra sutural bones present.


Embryonic origins

The neurocranium arises from paraxial mesoderm. There is also some contribution of ectomesenchyme. In Chondrichthyes and other cartilaginous vertebrates this portion of the cranium does not ossify; it is not replaced via endochondral ossification.

See also

References

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.