Oral Mucosa

Question 1

Define the oral mucosa.

Answer 1

It is the moist lining of the oral cavity. It varies in different areas according to function and to the mechanical influences that bear upon them.

Question 2

What are the funtions of oral mucosa?

Answer 2

1- Protection
2- Sensation
3- Secretion
4- Thermal Regulation

Question 3

What are the 2 layers of oral mucosa? ans what is their origin?

Answer 3

1- The surface or oral epithelium, derived from the ectoderm.(and endoderm)
2- the lamina propria, connective tissue, derived from ectomesenchyme.

Question 4

What are the epithelial ridges? What’s their function?

Answer 4

• They are the irregularities in the basement membrane that connects the oral epithelium and the lamina propria together. They are often called epithelium ridges or pegs.
• They interdigitate with the corresponding connective tissue ridges or papillae. This arrangement makes a larger surface area that provides:
  1- better attachment
  2- enables forces applied at the surface of the
  epithelium to be dispersed over a greater
  area of connective tissue.
  3- ensures better nutrient to the epithelium which
  is devoid of blood vessels.

Question 5

Complete : The stratified squamous epithelium may be:
1- …………….
2- ……………
3- ……………

Answer 5

1- Keratinized
2- Parakeratinized
3- Non-keratinized

Question 6

Write short notes on the basal layer.

Answer 6

• It constitutes the proliferation compartment.
• It represents the least differentiated cells of the epithelium.
• The cells are high cuboidal or low columnar and are arranged in one row on a well-defined basement membrane.
• The are attached to each other by desmosomes and to the basement membrane by hemidesmosomes.
• They contain the usual cell organelles and keratin filaments.
• They are 2 types : - serrated cells
  - stem cells

Question 7

Compare between Serrated cells and Stem cells.w

Answer 7

SERRATED CELLS:

• Heavily packed with keratin filaments.
• Specialized for anchoring the epithelium to the lamina propria.
• The serrations increase the surface epithelium for attachment and are plentiful in gingival epithelium and hard palate.
• The are seen by EM.

STEM CELLS:

• provide new cells.
• are smooth in shape.
• When a stem cell divides, one daughter cell remains a stem cell in the basal layer, while the other divides and undergoes differentiation and maturation as it migrates to the surface to replace a desquamated cell.