Embryology Flashcards
Differential process – increase in size or number
Growth
Physiologic/behavioral process – increases in organization or complexity
Development
When is the critical period for formation of the face and mouth?
4 - 14 week intrauterine!
Time frame for proliferative period, embryonic period, and fetal period…
proliferatie = 0-2 weeks Embryonic = 2-8 weks Fetal = 8 weeks = 9 months
week 1 (what happens) (2 things)
bilaminar disc forms from zygote
differentiation of ectoderm and endoderm
week 2 (What happens) (what does this lead to)
Gastrulation!!
leads to trilaminar disc (with mesoderm)
week 3 (what happens)
Neuralation stage! (CNS forms)
neural tube forms from the neural plate
How do neural crest cells migrate from the neural tube?
They migrate laterally and ventrally!
Fetal Alcohol Syndrome signs… What stage does it affect?
Stage 1 – organization of germ layers
ventricles of the brain fail to separate
mid face deficiency!
Foregut vs. Midgut vs. Hindgut
Foregut = digestive tube from throat Midgut = small intesting, ascending colon, transverse colon Hindgut = descending colon, sigmoidcolon, and rectum!
When does the oral pit first appear?
4th week!
What is the name for the early oral cavity?
Stomodeum
When does the heart start to beat?
4th week!
When does the oropharyngeal membrane rupture to open the oral cavity to the tubular foregut?
5th week!
When does the nasal cavity start fo form? Also the point of migration of neural crest cells into the five facial processes!
4th week!
When do most major malformations of the craniofacial complex originate?
transformation of the branchial arches!
When does the mandible begin ossification?
late 6th week
hemifacial microsomia (what is the defect?)
lack of tissue on the affected side of the face!!
1st Pharyngeal Arch! (what does it form, bones and muscles…)
mandibular arch – muscles of mastication
2nd pharyngeal arch (what does it form?)
hyoid ach == facial muscles, and hyoid bone
What cranial nerves go with the pharyngeal arches?
1 = V 2 = VII 3 = IX 4 = X 6 = XI
What do the 5 pharyngeal pouches form?
EPTSU
1 = middle ear and eustachian tube 2 = palaatine tonsils 3 = inferior parathyroids and thymus! 4 = superior parathyroids 5 = ultimobranchial body
Which branch becomes the common carotid arteries?
3rd arch!
What branch becomes the dorsal aorta?
4th arch
