L3-Palate Flashcards
The fatty zone, where adipose is found in the submucosa, makes up what part of the palate?
The glandular or mucous zone is made up of glandular tissue, what part of the palate is it found in?
The fatty zone is the Anterior 1/3
The glandular zone is in the posterior 2/3
The lamina propria is what part of the mucosa?
The thin connective tissue component that lies deep to the epithelial portion of the mucosa
What is the mucoperiosteum?
Mucoperiosteum is where the mucosa is firmly bound to the periosteum of the bone.
What are rugae where are they found?
Rugae are transverse ridges on the anterior, ventral surface of the hard palate
The roof of the oral cavity is bisected into two halves by a midline seam. What is this midline seam called?
Palatine Raphae
The secondary palate…
1) is formed from what two shelves?
2) to form what parts of the palate?
3) and separate what two cavities?
1) Formed from palatine shelves
2) Forms hard AND soft palate
3) Separates oral and nasal cavities
At 7 weeks the palatal shelves are forming from the maxillary processes and are directed downwards? Why do they initially grow downwards at 7 wks instead of sideways?
B/c the developing tongue is in the way of palate formation.
At week 8 the tongue is depressed, which way do the previously descending palatal shelves move now?
The palatal shelves are ELEVATED to the middle but they do not fuse.
At what week do the palatal shelves fuse at the midline? What else do they fuse with at this time?
Week 9. Also fuse with descending nasal septum.
During wk 8 what happens to surface epithelial cells? Why does this happen?
Surface epithelial cells die. This exposes basal epithelial cells that are rich in surface carbohydrates. The basal cells adhere and form a midline epithelial seam.
The seam is initially 2 layers thick but must be removed for continuity of the ectomesenchyme cells b/t processes. Why is this important?
Imp b/c ectomesenchyme cells are integral in formation of hard and soft tissue structures in the cranium. Ectomesenchyme is the connective tissue that must fuse together.
During the “transformation” event of the palatine shelves the epithelial tissues lose their basal laminae and epithelial character and “transform” into fibroblast cells to form a continuous layer. Why?
The newly formed fibroblasts allow bone to gradually grow to the midline and form the hard palate.
What is the difference b/t cleft lips and cleft palates?
Cleft palates form when the palatal shelves fail to contact due to a number of reasons.
Cleft lips are caused when the maxillary processes fail to fuse with the intermaxillary segment.
Van der Woude Syndrome is an autosomal dominant form of cleft lip or palate. In studies what gene has been implicated in causing this syndrome?
IRF6 transcription factor gene has been implicated by many studies. It will cause Van der Woude Syndrome when there is a deletion in the IRF6 gene as well as when certain substitutions take place in the sequence of IRF6.
