Sebaceous Gland and Hair Follicle: Skin Structure
Quick facts
- Definition
- The sebaceous gland produces sebum; the hair follicle is the canal where the hair grows. Together they form the pilosebaceous unit.
- Where they are
- In the dermis, opening onto the skin surface (the pore).
- Where there are more
- The central face, such as the forehead, nose and chin.
- Relation to HOF
- Active acne and oily skin weigh on the decision of when and how to perform procedures.
The sebaceous gland is a small gland in the dermis that produces sebum, a mixture of lipids that lubricates the skin and helps maintain the skin barrier. The hair follicle is the canal in which the hair grows. Both structures open at the same point, which is why they are treated as a single unit, the pilosebaceous unit.
How does the unit work?
Sebum is produced in the gland and flows up the follicle to the surface, where it spreads over the epidermis. The pore you see on the skin is the opening of that canal. Gland activity varies with hormones, age, genetics and climate, and is higher in the central face.
Where does this show up in HOF routine?
The pilosebaceous unit is the setting of acne vulgaris: when the follicle becomes blocked, sebum builds up and inflammation may follow. This matters for two reasons. The first is oily-looking skin and enlarged pores, a frequent concern that volume does not solve. The second is safety: an active inflammatory lesion in the injection area is usually a reason to postpone, depending on the professional's assessment.
| Structure | Layer | Function |
|---|---|---|
| Sebaceous gland | Dermis | Produces sebum |
| Hair follicle | Dermis, opening onto the epidermis | Houses the hair and carries the sebum |
| Pore | Surface | Exit of the unit |
Frequently asked questions
What is the pilosebaceous unit?
It is the set formed by the hair follicle, the sebaceous gland and the small arrector pili muscle. Sebum travels up the follicle canal and reaches the skin surface through the pore.