Prenatal Growth Flashcards Preview

Dent Station Exam fall 2015 > Prenatal Growth > Flashcards

Flashcards in Prenatal Growth Deck (16)
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1
Q

Ectoderm

A

epidermix, nasal & oral mucosa, tooth enamel, lens, oragns of hearing/equilibrium

2
Q

Endoderm

A

lining of posterior tongue, pharynx, tympanic cavity, respiratory tract, parts of thyroid

3
Q

Mesenchyme

A

bones, muscles, & connective tissues of the head (and all other parts of the body)

head mesenchyme is from two sources:

paraxial mesoderm (somitomeres & somites)

neural crest (via surface ectoderm)

4
Q

mesenchyme from neural crest

A

bones & connective tissues of face & anterior skull (vault + base)

5
Q

mesenchyme from paraxial mesoderm

A

all skeletal mm., bones & connective tissues of posterior skull (vault + base)

6
Q

Ossification pathways: intramembranous

A

mesenchymal tissue located just below the dermis transforms directly into bone

lateral

7
Q

ossification pathways: endochondral

A

mesenchyme forms a hyaline cartilage model; the cartilage is then replaced by bone tissue

medial

8
Q

palatogenesis

A

inferior views of medial nasal prominences merging together to form primary hard palate (premaxilla)

medial nasal prominences give rise to: premaxilla and upper incisors

inferior view of lateral palatine processes merging to form secondary hard palate

9
Q

Cleft lip &/or anterior cleft palate

A

results from mesenchyme deficiences; failure of tissues to merge; vascular defects; etc. in maxillary prominences & median nasal prominences

maybe uni or bilateral

10
Q

posterior cleft palate (aka isolated cleft)

A

results from growth distortions in palatine shelves causing defective midline fusion & w/ nasal septum

soft palate may or may not be involved

11
Q

Lateral facial cleft: macrostomia

A

poor merging of max and man prominences; condition manifests as a large mouth on one or both sides

12
Q

congenital craniofacial defects

A

most craniofacial malformations occur during the embryonic period (weeks 2 to 8)

deformations and growth disturbances (diruptions) occur in the fetal period (weeks 9 to 40)

13
Q

Fetal alcohol syndrome

A

caused by maternal intake of alcohol

different effects due to timing of exposure(s)

affects development of all structures; apoptosis of early cell populations; damaged DNA; cognitive defects

may stimulate premature differentiation of mesenchyme of facial primordia

characteristic facial features

14
Q

Holoprosencephaly

A

defective formation of forebrain resulting in malformation of structures depending on molecular signaling from this region; reduction in frontonasal process structures

15
Q

Frontonasal dysplasia

A

excessive tissue in frontonasal process structures

16
Q

Pierre Robin Sequence (Robin Syndrome)

A

occurs in 1:8

may be caused by intrauterine constriction of mandibular growth; neurologic conditions affecting jaw movements; genetic

results in sequence of effects on 1st arch structures; tongue interferes w/ formation of secondary palate

triad of micrognathia, cleft palate, & glossoptosis (retracted tongue)

normal intelligence