Gingival Epithelium | Layers | Microscopic features | Differences | Periodontology | Animated

Summary

This video explores the microscopic structure of the gingiva, focusing on the gingival epithelium. It covers the layers of the oral epithelium—stratum basale, stratum spinosum, stratum granulosum, and stratum corneum—highlighting their roles in cell regeneration, protein synthesis, and defense. The video also introduces melanocytes, Langerhans cells, and Merkel cells, which contribute to pigmentation, immune defense, and sensory function. Additionally, it dives into sulcular and junctional epithelium, explaining their unique structures and functions, including the protective seal of the junctional epithelium. A comprehensive understanding of gingival anatomy is provided.

Takeaways

• 😀 Gingival architecture is made up of gingival epithelium and connective tissue, with this video focusing on the epithelium.
• 😀 The gingival epithelium is classified into three types: oral epithelium, sulcular epithelium, and junctional epithelium.
• 😀 Oral epithelium consists of four layers: stratum basale, stratum spinosum, stratum granulosum, and stratum corneum.
• 😀 Stratum basale (basal layer) is the deepest, responsible for mitotic divisions and producing new keratinocytes.
• 😀 Stratum spinosum contains cells that are larger, polygonal, and have a spiny appearance due to desmosomes.
• 😀 Stratum granulosum has keratohyalin granules that form cross-links in keratin filaments, adding strength to the epithelium.
• 😀 Stratum corneum is the outermost layer where cells are flat, dead, and shed during desquamation.
• 😀 Non-keratinocytes such as melanocytes, Langerhans cells, and Merkel cells are also present in the gingival epithelium.
• 😀 The basal lamina is a thin extracellular matrix layer that provides structural support and facilitates nutrient exchange.
• 😀 Sulcular epithelium is non-keratinized and thinner than oral epithelium, with only two layers: stratum basale and stratum spinosum.
• 😀 Junctional epithelium has a unique structure, with two basal lamina layers and high proliferative rates, serving as a protective seal around the tooth.

Q & A

What are the main components of the gingival architecture?

The gingival architecture is composed of the gingival epithelium and the underlying connective tissue. This video focuses mainly on the epithelium.

How is the gingival epithelium classified?

The gingival epithelium can be loosely categorized into three types based on location and composition: the oral epithelium, the sulcular epithelium, and the junctional epithelium.

What are the layers of the oral epithelium?

The oral epithelium consists of four layers: the stratum basale (basal layer), stratum spinosum (prickle cell layer), stratum granulosum (granular layer), and stratum corneum (corneal layer).

What is the main function of the stratum basale?

The stratum basale is the deepest layer, attached to the basement membrane. It contains cuboidal to columnar cells that undergo frequent mitotic divisions, supplying new keratinocytes.

Why do cells in the stratum spinosum have a spiny appearance?

Cells in the stratum spinosum are polygonal and exhibit tiny junctions called desmosomes. The shrinkage of these cells during tissue preparation gives them a spiny or prickly appearance.

What is the role of keratohyalin granules in the stratum granulosum?

Keratohyalin granules, found in the stratum granulosum, are rich in filaggrin proteins. These proteins form crosslinks between keratin filaments, contributing to the strength of the epithelium.

What is desquamation?

Desquamation refers to the natural shedding of dead skin cells. In the case of the oral epithelium, the cells in the stratum corneum are eventually shed due to degeneration of their nuclei.

What is the function of melanocytes in the gingiva?

Melanocytes are specialized cells that produce melanin, responsible for the pigmentation of the gingiva. They are found in the basal and spinous layers of the epithelium.

What is the role of Langerhans cells in the gingiva?

Langerhans cells are dendritic cells located in the supra-basal layers of the gingiva. They act as antigen-presenting cells and play a crucial role in the immune defense.

How does the junctional epithelium protect the gum tissues?

The junctional epithelium forms a collar-like band around the tooth, sealing the gingival crevice. This seal prevents harmful bacteria from entering the gingival tissues and protects the gums.

What is unique about the structure of junctional epithelium compared to other types of epithelium?

Junctional epithelium consists of only two layers and has both an internal basal lamina (attached to the tooth via hemidesmosomes) and an external basal lamina (connecting the epithelium to the underlying connective tissue). This unique attachment to the tooth surface is unlike other epithelium types.