Summary
The chondrocranium (or cartilaginous neurocranium) is the primitive cartilaginous skeletal structure of the fetal skull that grows to envelop the rapidly growing embryonic brain.[1]
| Chondrocranium | |
|---|---|
| Details | |
| Identifiers | |
| Latin | chondrocranium |
| TA98 | A02.1.00.009 |
| TA2 | 357 |
| FMA | 76621 |
| Anatomical terminology [edit on Wikidata] | |
The chondrocranium in different species can vary greatly, but in general it is made up of four components, the sphenoids, occipitals, otic capsules, and nasal capsules.[2]
In humans, the chondrocranium begins forming at 28 days from mesenchymal condensations and is fully formed between week 7 and 9 of fetal development. While the majority of the chondrocranium is succeeded by the bony skull, some components do persist into adulthood.[1] In cartilaginous fishes (e.g. sharks and rays) and agnathans (e.g. lampreys and hagfish), the chondrocranium persists throughout life.[3] Embryologically, the chondrocranium represents the basal cranial structure, and lays the base for the formation of the endocranium.[4]
Divisions edit
The portion of the chondrocranium that is associated with the notochord is termed the chordal chondrocranium and is formed from mesodermally-derived mesenchyme. The more rostral portion of the chondrocranium that lie anterior to the notochord constitutes the prechordal chondrocranium, and is derived primarily from neural crest-derived mesenchyme.[1]
See also edit
References edit
- ^ a b c Salentijn, L. Biology of Mineralized Tissues: Prenatal Skull Development, Columbia University College of Dental Medicine post-graduate dental lecture series, 2007
- ^ Kardong, Kenneth V. (2015). Vertebrates: Comparative Anatomy, Function, Evolution. New York: McGraw-Hill Education. p. 701.
- ^ Kent, G.C & Miller, L. (1997): Comparative Anatomy of the Vertebrates. Wm. C. Brown Publishers. ISBN 0-697-24378-8.
- ^ Romer, Alfred Sherwood; Parsons, Thomas S. (1977). The Vertebrate Body. Philadelphia, PA: Holt-Saunders International. pp. 216–247. ISBN 0-03-910284-X.