Skull Embryology - ACht Flashcards
Which bones are cartilaginous and which are membranous?
Cartilaginous
- ethmoid
- sphenoid
- occipital base
- petrous temporal
- temporal- mastoid
Membranous
- flat bones of vault:
- parietal
- frontal
- squamous occipital
What structure defines the boundary between bones derived from occipital somites and those derived from neural crest cells?
The middle of the hypophyseal fossa
What bones are formed from viscerocranium?
bones of face, hyoid, and middle ear bones
What viscerocranial bones are cartilaginous and membranous?
Cartilaginous
malleus incus stapes hyoid temporal, styloid
Membranous
premaxilla maxilla zygomatic temporal, squamous mandible
What is craniosystosis?
premature closing of skull sutures producing a misshapen skull
What kind fo skull abnormality is produced by a premature fusion of the coronal suture?
brachycephaly
fusion of coronal & lambdoidal sutures produces:
a “tower skull”
oxycephaly, turricephaly, acrocephaly
What is plagocephaly?
fusion of coronal & lambdoidal sutures unilaterally produces an asymmetrical skull.
What is a fusion of the sagittal suture that produces a long front-to-back diameter skull.
Scaphocephaly
Microcephaly =
Small head due to brain that fails to grow
A skull defect in which the meninges and or brain herniate out of the skull:
Cranioschisis
What is Alpert Syndrome?
Autosomal dominant genetic disorder characterized by craniosynostosis and other congenital abnormalities e.g., syndactyly of hands and feet, mental retardation.
What is acrania?
No skull formed
What is meroanencephaly?
some poorly formed brain stem tissue present
Anencephaly means:
No brain
