OCB Overview Flashcards
What is epigenesis?
Organs forming de novo
What does triploblastic mean?
Have three germ layers
What are the three germ layers?
Ectoderm
Mesoderm
Endoderm
How many Carnegie stages are there and how long do these last?
23 stages lasting up to 60 days (early development)
What germ layer are neural crest cells derived from?
Ectoderm
What do cranial neural crest cells develop into?
Chondroblasts/cytes - cartilage
Osteoblasts/cytes - bone
Odontoblasts and cementoblasts - teeth
What do trunk neural crest cells develop into?
Melanocytes
Neurons (sensory and sympathetic)
Adrenomedullary cells
Schwann cells
What does diphyodont mean?
Has two successive sets of teeth
What does heterodont mean?
Teeth have different forms
What does thecodont mean?
Teeth are fixed in sockets in jaw
What is cleidocranial dysplasia?
Mutation in Runx2 gene which causes continuous tooth formation
Supernumerary teeth form as third dentition
Often with bone hypoplasia
What gene usually inhibits the formation of successional teeth?
Runx2
What is the most common form of ectodermal dysplasia?
Hypohidrotic ED
What are the symptoms of hypohidrotic ectodermal dysplasia?
Sparse hair
Abnormal dentition
Absence of sweat glands, tear ducts, salivary glands…
