The epidermis provides a physical barrier due largely to the presence of (a) melanin

Which epidermal cell type is most numerous? (a) keratinocyte, (b) melanocyte, (c) dendritic cell, (d) tactile cell.

Which cell functions as part of the immune system? (a) keratinocyte, (b) melanocyte, (c) dendritic cell, (d) tactile cell.

The epidermis provides a physical barrier due largely to the presence of (a) melanin, (b) carotene, (c) collagen, (d) keratin.

Skin color is determined by (a) the amount of blood, (b) pigments, (c) oxygenation level of the blood, (d) all of these.

The sensations of touch and pressure are picked up by receptors located in (a) the stratum spinosum, (b) the dermis, (c) the hypodermis, (d) the stratum corneum.

Which is not a true statement about the papillary layer of the dermis? (a) it is largely areolar connective tissue, (b) it is most responsible for the toughness of the skin, (c) it contains nerve endings that respond to stimuli, (d) it is highly vascular.

Skin surface markings that reflect points of tight dermal attachment to underlying tissues are called (a) tension lines, (b) papillary ridges, (c) flexure lines, (d) dermal papillae.

Which of the following is not an epidermal derivative? (a) hair, (b) sweat gland, (c) sensory receptor, (d) sebaceous gland.

An arrector pili muscle (a) is associated with each sweat gland, (b) can cause a hair to stand up straight, (c) enables each hair to be stretched when wet, (d) provides new cells for continued growth of its associated hair.

The product of this type of sweat gland includes protein and lipid substances that become odoriferous as a result of bacterial action: (a) apocrine gland, (b) eccrine gland, (c) sebaceous gland, (d) pancreatic gland.

Sebum (a) lubricates the surface of the skin and hair, (b) consists of cell fragments and fatty substances, (c) in excess may cause seborrhea, (d) all of these.

The rule of nines is helpful clinically in (a) diagnosing skin cancer, (b) estimating the extent of a burn, (c) estimating how serious a cancer is, (d) preventing acne.

Which epidermal cells are also called prickle cells? Which contain keratohyaline and lamellar granules?

Is a bald man really hairless? Explain.

You go to the beach to swim on an extremely hot, sunny summer afternoon. Describe two ways in which your integumentary system acts to preserve homeostasis during your outing.

Distinguish clearly between first-, second-, and third-degree burns.

Describe the process of hair formation, and list several factors that may influence (a) growth cycles and (b) hair texture.

What color does carotene impart to the skin?

Why does skin wrinkle and what factors accelerate the wrinkling process?

Explain each of these familiar phenomena in terms of what you learned in this chapter: (a) pimples, (b) dandruff, (c) greasy hair and shiny nose, (d) stretch marks from gaining weight, (e) freckles.

Count Dracula, the most famous vampire, rumored to have killed at least 200,000 people, was based on a real person who lived in eastern Europe about 600 years ago. He was indeed a monster, although he was not a real vampire. The historical Count Dracula may have suffered from which of the following? (Hint: See Related Clinical Terms.) (a) porphyria, (b) EB, (c) halitosis, (d) vitiligo. Explain your answer.

Why are there no skin cancers that originate from stratum corneum cells?

A man got his finger caught in a machine at the factory. The damage was less serious than expected, but the entire nail was torn off his right index finger. The parts lost were the body, root, bed, matrix, and eponychium of the nail. First, define each of these parts. Then, tell if this nail is likely to grow back.

On an outline diagram of the human body, mark off various regions according to the rule of nines. What percentage of the total body surface is affected if the skin over the following body parts is burned? (a) the entire posterior trunk and buttocks, (b) an entire lower limb, (c) the entire front of the left upper limb.

A common belief is that having your hair cut makes it become thicker. Explain why this belief is not true.