prenatal development Flashcards
five principle stages
1) germ layer formation
- initial organization of craniofacial structures
2) neural tube formation
- oropharynx
3) origins, migrations, and interactions of cell populations
-especially neurocrest cells
- hemifacial microsomnia
4) formation of organ systems
- pharyngeal arches, primary and secondary palates
- cleft lip and palate
5) final differentiation of tissue
- skeletal, muscular, and nervous
- crouzon syndrome
gestation
1) 266 days from fertilization
2) ovum every 28 days, lasts 24 hours
3) millions of sperm, viable 6 dys
4) conceptions most likely on day of ovulation or 2 days preceding
three periods of prenatal development
1) proliferative
weeks 1-2
2) embryonic (organogenetic)
weeks 3-8
3) fetal
week 9 - birth
development of the head and face is one of the most complex events
youtube video
development of the face
1) TFs and signalling molecules coordinate it
2) 4th week of gestation
3) migration of neural crest cells combine with mesodermal cells and establish facial primordia
4) maxillary prominences enlarge and grow towards each other and the nasal prominences
5) disturbances can result in craniofacial anomolies
genes in craniofacial morphogenesis
1) polarizing signals
2)GFs and receptors
3) TFs
4) cell adhesion molecules
5) ECM
complex choreography
1) mesenchymal and epithelial tissues response to TFs and GFs
2) mutation or interruptions of process leads to congenital anomalies of facial and airway structures
3 ) 4 week
- upregulated genes
4) 5th weeks
- upregulated in frontonasal
5) 6 weeks
- lateral and mesial nasal prominences
germ layer derivatives
1) ectoderm
- neural crest
- nervous system, skin, hair
2) mesoderm
- muscles, bones, and circulatory system
3) endoderm
- digestive system, lungs, urinary tract, and other vital organs
4) almost all the tissue of the face and neck originate from ectoderm
sensitivity during embryonic period
1) different systems vary in sensitivity
2) morphogenic / organogenic period
3) fetal period has functions, and less so morphogenesis
- except the palate, which is closing
malformed conceptuses
1) only 10% of malformation progress to birth
2) 8% diagnoses at birth
3) 2% diagnoses later
congenital anomaly
1) deviation from normal shape or structure of a body part dating from birth
congenital disease
deviation from function, without or without anomaly
major congenital anomalies
1) 3%
2) with minor goes up to 6-15%
causes of congenital
1) environmental / genetic 65%
2) genetic 25%
3) environmental 10%
genetic
1) genetic factors play a role in etiology and it can be passed from individual to offspring
nongenetic
anomaly caused by environment, non genetic factors that disturb genetically programmed development of a fetus
most congenital anomalies result from
genetic x environment
- multifactor
- genetic: susceptibility
- environment: triggering them ^
- ex NTD, congenital heart defect, etc
lifestyle choices
1) diet, smoking, and environmental factors affect disease risk
food is medicine
1) change likelihood of agouti obese animal on the bases of nutrients that were given to mother during pregnancy
2) epigenetic modification
- methyl group turning on/off
3) BPA exposure and gave them methyl donors was able to reverse the effect
cleft palate and lip
1) 1st most common anomaly
2) multifactorial etiology and risk of recurrance
- sex of person also affects it
3) start during formation of organ systems
hemifcial microsomnia
1) origins, migrations, and interactions of cell populations, especially neurocrest cells
crouzon syndrome
1) facial differentiation of tissue
