Clinical note: Sebaceous glands become much more active after puberty and can become affected by acne vulgaris, in which blocked ducts or hair follicles produce small white lesions (comedones) caused by build-up of sebum and dead cells. The disease is normally self-limiting, but comedones can become sites of bacterial infections. Sometimes there is marked scaring left in the wake of the inflammation.

On slides identify the

• Secretory portions and darker-staining ducts of merocrine (“eccrine”) sweat glands.
• Myoepithelial cells surrounding the secretory units (better shown on slide 89).
• In the ducts, note the unusual stratified cuboidal epithelium lining the ducts and the lack of myoepithelial cells.

Examine the micrograph of apocrine sweat glands and look for these structures

• Compare the lumen size and overall histological appearance of apocrine sweat glands to the more common merocrine/eccrine sweat glands.

What is the functional significance of having apocrine sweat glands in skin of only certain body areas?

Examine the structure of nails and their association with other parts of a digit as shown on the demo slide.

How does the structure of a nail and nail bed compare with that of a hair follicle?

More on skin appendages.