Anatomy Ch 5: Integumentary System (Mastering A&P)

Why does your skin remain red after a bad sunburn?

Inflammation causes increased blood flow.

What is the role of the hair follicle?

The hair follicle serves as an anchor for the hair shaft.

Which of the following best explains the fact that eyebrows do NOT grow as long as the hair on the head?

The hair follicles of the eyebrows are active for only a few months before becoming inactive; the hair follicles in the scalp are active for years before becoming inactive. The hair follicles in the scalp remain active for up to ten years, while those of the eyebrow are only active for up to four months before becoming inactive.

Which of the following would be a sign of a melanoma?

asymmetry Cancerous growths exhibit asymmetry. Benign growths exhibit symmetry, regular borders, uniform coloration, and they are usually less than 6 mm in diameter.

Which of the following is NOT an immediate threat to the system as a result of burns?

bacterial infection While it is true that infection is a long term threat, the fluid balance must be restored first in order to stabilize the burn trauma.

Earwax is made by __________.

ceruminous glands Ceruminous glands are modified apocrine sweat glands found in the lining of the external ear canal. Their secretion mixes with sebum produced by nearby sebaceous glands to form a sticky, bitter substance called cerumen, or earwax, which is thought to deter insects and block entry of foreign material.

Why would a third-degree burn be less painful than a first- or second-degree burn involving the same body area?

destruction of underlying pain receptors

In alopecia, new hair growth stops because cell division is inhibited in the_________.

hair matrix cell division in the hair matrix produces the cells that will form the hair fiber and the inner root sheath. The hair matrix epithelium is one of the fastest growing cell populations in the human body.

What is the most common cell type in the epidermis?

keratinocytes Keratinocytes are the primary cells that form the stratified layers of the epidermis

Which of the following is NOT a function of sebum?

protection from UV radiation This is false; it is melanin (not sebum) that protects the skin from the damaging effects of UV radiation. Sebum serves as a lubricant, an antibacterial agent, and protects against water loss in low-humidity conditions.

Which glands secrete an oily product that softens the skin and hair?

sebaceous glands Sebaceous glands secrete an oily substance called sebum. Sebum softens and lubricates the hair and skin, slows water loss from the skin when external humidity is low, and has bactericidal properties.

During cold weather, blood vessels located in the dermis undergo vasoconstriction restricting blood flow into the skin. This produces additional body heat by routing blood to what effector organ?

skeletal muscle

Which stratum of the epidermis contains the stem cells responsible for regenerating the more superficial layers?

stratum basale The stratum basale is the deepest layer of the epidermis and consists of one layer of actively mitotic stem cells. The stem cells in this layer generate the cells that will migrate to the more superficial layers: spinosum, granulosum, and corneum.

Which of the following does NOT protect the skin from bacteria?

the temperature of the skin The temperature of the skin does not protect the skin against bacteria. In fact, the temperature of the skin is ideal for many types of bacteria.