Skin barrier

Definition

The skin barrier is the outermost layer of the skin that acts as a physical and chemical defense against pathogens. It prevents harmful microorganisms from entering the body and helps maintain overall skin health.

5 Must Know Facts For Your Next Test

1. The skin barrier is composed mainly of the stratum corneum, which consists of dead keratinized cells.
2. It functions as both a physical block and a chemical shield due to the presence of antimicrobial peptides and lipids.
3. The acidic pH of the skin surface (around 4.5-5.5) inhibits microbial growth.
4. Disruptions to the skin barrier can lead to increased susceptibility to infections and inflammatory conditions.
5. Sebum produced by sebaceous glands adds an oily layer that further protects against microbial invasion.

Review Questions

• What are two main components of the skin barrier that prevent pathogen entry?
• How does the acidic pH of the skin contribute to its function as a barrier?
• What role does sebum play in maintaining the integrity of the skin barrier?

Related terms

Stratum Corneum: The outermost layer of the epidermis made up of dead keratinized cells.

Antimicrobial Peptides: Small proteins produced by epithelial cells that kill or inhibit microbial pathogens.

Sebum: An oily substance produced by sebaceous glands that helps protect and lubricate the skin.