Skull and Mandible Development Flashcards
How many cranial bones are there
8 cranial bones
How many facial bones are there
14 facial bones
What are the MAIN cranial bones?
Frontal - 1
Occipital - 1
Parietal - 2
Temporal - 2
What are the MAIN facial bones?
Nasal - 2
Zygomatic - 2
Maxilla - 1
Mandible - 1
What embryonic structure does the eye come from
optic placode
what structure does the nose, philtrum, and forehead come from
frontonasal prominence
what structure does the nose come from
nasal or olfactory placode
what structure does the stomadeum become
oral cavity
what early structures come from pharyngeal arch 1
maxillary and mandibular prominences
what structure does the nose come from
otic placode
eye and ear development during weeks 4-5
rapid brain development and frontonasal process is formed. The optic placode is formed, and auricular hillocks ( 3 hillocks each from pharyngeal arches 1 and 2) are also formed.
eye and ear development during weeks 6-7
lateral brain development. the optic placode moves more anteriorly. the auricular hillocks and the external auditory meatus migrate to the otic placode
eye and ear development during week 10
the optic placode moves in front of the face. The hillocks and the meatus have joined to form the ear.
Nose and Lip development during week 5
Nasal placode forms
Lateral nasal process forms
Medial nasal process forms
Nose and Lip development during week 6
medial migration of frontonasal process. The lateral nasal process and maxillary process join to form the nasolacrimal groove
nose and lip development during week 7
medial nasal and frontonasal process form the philtrum. Medial and maxillary join to form the upper lip
nose and lip development during week 10
medial process forms philtrum, medial maxilla, primary palate, medial nose
what parts form the nasolacrimal groove
lateral nasal process and the maxillary process
what parts join to form the philtrum
medial nasal process and the frontal nasal process
what parts join to form the upper lip
medial nasal process and maxillary process
what is the neurocranium
encases the skull
what are the bones that make up the membranous neurocranium
flat bones
what is the cartilaginous neurocranium also called
chondrocranium
what are the two parts of the neurocranium
chondrocranium and membranous cranium
what are the two structures that the neurocranium is derived from
neural crest cells and the somites
Where is the viscerocranium
face
what embryonic structure(s) is the viscerocranium made of
entirely neural crest cells
What are the bones that make up the viscerocranium:
Facial bones: mandible, maxilla, zygoma, vomer, palatine, lacrimal, nasal, conchae
what are the bones that make up the neurocranium
neural crest cells: temporal(squamosal), sphenoid, ethmoid, frontal
Mesoderm: temporal(petrosal), occipital, parietal
During development of the skull: where does the cartilage development begin?
it begins at the midline
where is the chondrocranium positioned
base of the skull/cranium
what are the bones that make up the chondrocranium
part of the occipital bone, ethmoid, sphenoid, temporal petrosal, and meckels cartilage
what is intramembranous ossification
absence of cartilage model
what bones develop through intramembranous ossification
flat bones of the face, skull, mandible, clavicle
what is endochondral ossification
when there is a cartilage model precursor
what bones develop through endochondral ossification
long bones, bones of extremities, vertebrae, ethmoid, sphenoid
describe process of intramembranous ossification
mesenchymal cells aggregate and proliferate, the mesenchymal cells differentiate into osteoblasts, and secrete osteoid at multiple centers of ossification. Osteiod is mineralized.
describe process of endochondral ossification
a hyaline cartilage model is used as a template during the generation of long and short bones. There are mesenchymal osteoblasts for two ossification centers, osteoid is deposited in place of the cartilage material
when does endochondral bone growth begin and what does it depend on
it begins during the second trimester and continues into early adulthood. and it depends on the presence of epiphyseal cartilage
how many zones of epiphyseal cartilage are there and what are they called
- reserve cartilage
- proliferation
- maturation
- hypertrophy and calcification
- degeneration or resorption
- osteogenic zone
cranioschisis
cranial vault fails to form: fontanelles dont turn into sutures
craniosynostisis
premature closing of one or more cranial sutures
what gene family mutation causes craniosynostosis
mutation in the FGFR genes
scaphocephaly
sagittal suture fails, expansion of the frontal and occipital bone, long and narrow
brachycephaly
coronal suture fails, stout skull
plagiocephaly
unilateral coronal and lamboid sutures, asymmetric flattening of one side of the skull
cloverleaf skull
thanatophoric dwarfism FGFR3
FGF Signal Transduction pathway involved which type of receptor?
Receptor Tyrosone Kinase: type 1 and type 2. Upon reception, type 2 phosphorylates type 1. Type 2 and type 1 are dimers respectively.
Pfeiffer Syndrome
Mutation on FGFR1 and FGFR2
Apert Syndrome
mutation in FGFR2
Crouzon Syndrome
mutation in FGFR2
Achondroplasia
mutation in FGFR3
