Term
| Describe the stages of palatal development. |
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Definition
primary palate - seperates nasal and oral cavity. small anterior portion of hard palate.
secondary palate - 2 palatal shelves inferiorly grow then vertically - posterior 2/3 of palate max canines and posterior teeth.
completion of palate - secondary palate meets primary and 3 fuse |
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Term
| what is the difference between primary and secondary palate? gives rise to? |
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Definition
| primary is anterior section - Premaxillary segment 1/3 portion of maxilla, secondary is back half - posterior 2/3 of hard palate - maxillary canine and posterior support. soft palate and uvula |
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Term
| Explain the completion of the palate? |
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Definition
| fusion between 1st and 2ndary palate fuse seperating nasal and oral cavity. |
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Term
| What are the developmental disturbances with the formation of the palate and related tissue. |
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Definition
| cleft palate (failure of fusion of the palatal shelves) and uvula. |
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Term
| Describe the formation of the nasal cavity and septum |
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Definition
| septum fuses with medial nasal processes which forms to palate creating a nasal cavity and fused septum |
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Term
| What does the tongue develop from and when? |
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Definition
| 4-8th weeks - from independent swellings located internally on the floor of the primitive pharynx, formed by first 4 branchial arches |
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Term
| Explain the development of the body of the tongue. |
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Definition
| triangular medium swelling called tuberculum impar. (medium tongue bud)then lateral lingual swellings grow over and fuse and the impar disappears |
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Term
| Explain the development of the base of the tongue |
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Definition
| pair of swellings called the copula, formed from messenchyme coming from 4th arch, overgrows 2nd arch to form base of tongue. Posteriorly a 3rd swelling (epiglottic) forms posterior region and epiglottis |
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Term
| How does tongue formation become complete? |
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Definition
| Tongue base and body fuse (lateral lingual swellings, copula, epiglottic) Tongue contracts and moves inferiorly and anteriorly so that the palatal shelves are not in the way. |
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Term
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Definition
4- 8 weeks Body: tuberculum impar and lateral swellings Base: copula overgrowing 2nd branchial arches
8th week: tongue: mergingof anterior swellings of the body and copula of the base |
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Term
| How do intrinsic muscles, lingual papillae, and taste buds develop? |
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Definition
1. primitive muscle cells migrate into developing tongue taking there motor supply 12 cranial nerve with. (mesoderm occipital somites)
2. appear end of eigth week - 11th week (fetal period)
3. 11-13th week inductive interaction between epithelial cells of tongue and nerve cells |
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Term
| Developmental disturbances in tongue? |
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Definition
| Ankyloglossia - short lingual frenum |
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