Langerhans Cells And Oral Epithelium: Histological Features

Langerhans Cells And Oral Epithelium: Histological Features

Question 1. Langerhans cells.
Answer:

Non-keratinocytes:

Origin: Bone marrow

Site: Suprabasal layer of epithelium.

Structure:

• Dendritic cell
• Has convoluted nucleus
• Has a small rod or flat-shaped granule called a Birbeck granule.
• Lacks desmosomal attachments.
• Appears as a clear cell histologically.

Functions:

• Recognizing and processing antigenic material.

Question 2. Junctional epithelium.
Answer:

• The epithelium of the gingiva which gets attached to the tooth is called the junctional epithelium.
• It resembles reduced enamel epithelium.
• It is non-differentiating, nonkeratinizing tissue
• It is highly permeable and has large intercellular spaces.
• It is formed by the fusion of reduced enamel epithelium and oral epithelium.
• It consists of flattened cells aligned parallel to the tooth surface.
• It has 3-4 layers apically and 15 – 30 layers coronally

Parts:

• Corona part – Thickest and has maximum permeability.
• Middle part – lias maximum adhesion
• Apical part – has maximum mitotic activity.

Question 3. Lamina propria.
Answer:

• The connective tissue supporting the oral epithelium is termed lamina propria.

Layers:

• The superficial papillary layer.
• Associated with the epithelial ridges Collagen fibers are thin and loosely arranged.
• Deeper reticular layer.
• Lies between the papillary layer and the underlying structures.
• Collagen fibers are arranged in thick bundles.

Consist of: