Skull, Face, and Palate Development Flashcards
What is the condition that occurs when a baby has a misshapen head by sitting in a car seat?
Deformational plagiocephaly
What portion is the neurocranium?
Around the brain
What portion is the viscerocranium?
Skeleton of the face
What forms the bones of the base of the skull?
Endochondral ossification
Where does the prechordal cartilage come from?
Neural crest cells
What does the prechondral cartilage contribute to?
Ethmoid bone
What does the parachordal cartilage contribute to?
Base of occipital bone
What does hypophysial cartilage contribute to?
Body of the sphenoid
Capsules surround…
The special sensory structures of the head
Olfactory capsule forms…
Ethmoid, nasal, lacrimal, and inferior concha
Otic capsule forms…
Petrous and mastoid parts of the temporal bone
Optic capsule forms
Greater and lesser wings of the sphenoid
Membranous neurocranium is derived from…
Neural crest cells
Membranous viscerocranium is derived from
First arch (maxillary prominence) and neural crest cells
Cartilaginous viscerocranium is derived from
First and second arches
When does the face begin to develop?
4th week
Five facial primorida forms
One frontonasal prominence, two maxillary prominences, and two mandibular prominences
What is continuous throughout the five prominences?
Mesenchyme cells
What is not present at birth?
Paranasal sinuses
Nasolacrimal duct is formed from
Ectoderm of nasolacrimal groove
What is the intermaxillary segment?
fusion of the paired medial nasal prominence
What does the medial nasal prominence give rise to?
Labial compartment
What are cranial sensory ganglia derived from?
Neural crest and ectodermal placodes
Five placodes form…
hypophyseal placode – Rathke’s pouch
olfactory placode – epithelium of nasal cavity
ventrolateral placode – ganglia of CN VII, IX and X
dorsolateral placode – otic placodes (membranous labyrinth, spiral and vestibular ganglia)
intermediate placode – profundal and trigeminal placodes – trigeminal ganglia
When does the primary palate begin to form?
End of 5th week, not completed until 12th week
When does the secondary palate begin to form?
6th week
What is acrania?
No calavria, associated with anecephaly
What is craniosyntosis?
Premature closure of the sutures
What is scaphocephaly?
Sagittal suture closes -> skull is LONG and NARROW
What is oxycephaly?
Coronal suture closes -> skull becomes TALL
What is plagiocephaly?
Asymmetric closure -> skull become twisted
What can cause plagiocephaly?
Dysfunction of CN IX and X
What is microcephaly?
Fontanelles close early and sutures close during the first year; a CNS defect whereby the brain and calvaria fail to grow; accompanied by severe mental retardation
Choanal atresia is…
Nasal cavity not continuous with pharynx
What is the acronym for choanal atresia?
C = coloboma of the iris, choroid
H = heart defect
A = atresia of choanae
R = retarded growth
G = genitourinary anomaly
E = ear defect
What is microstomia?
Excessive merging of maxillary and mandibular prominences
Cleft lip involves…
Only the lip
Anterior cleft involves…
Alveolar part of the maxilla, anterior to the incisive foramen
Posterior cleft involves…
Secondary palate through soft and hard palate
Median cleft involves…
Failure of medial nasal prominences -> Mohr syndrome
Oblique facial cleft extends
From upper lip to medial margin of orbit
Median cleft of the lower lip involves…
Failure of mandibular prominence to fuse
