5. Integumentary System

Why do the cells in the more superficial layers of the epidermis die?

The disease pemphigus vulgaris involves a patient's own immune system attacking the desmosomes between the epithelial cells of the skin. What changes would you expect to see with this disease?

Number the strata of thick skin epidermis from deepest (1) to most superficial (5). 

____Stratum spinosum     

____Stratum corneum     

____Stratum basale     

____Stratum lucidum     

____Stratum granulosum

Which of the following statements is false?

a. Thin skin lacks the stratum lucidum, whereas thick skin has all five epidermal layers.

b. Thick skin is located on the palms, the palmar surfaces of the fingers, the soles of the feet, and the plantar surface of the toes, whereas thin skin is located everywhere else.

c. Thick skin has numerous hairs, whereas thin skin lacks hairs.

d. Thin skin has a thin stratum corneum, and the other layers are thinner than what we find in thick skin.

Epidermal ridges are created by:

a. The epidermal papillae

b. Mounds of papillary dermis arranged into dermal ridges

c. Gaps between collagen bundles in the reticular layer

d. Tight binding of the reticular layer to deeper structures

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Carotene is a brown-black pigment that accumulates in the stratum corneum.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Increased amounts of blood flowing through the dermis lead to pallor in the skin.

Which type of burn involves the epidermis and all or part of the dermis?

a. First-degree burn

b. Second-degree burn

c. Third-degree burn

d. Fourth-degree burn

The type of skin tumor that involves the keratinocytes of the stratum spinosum is:

a. Basal cell carcinoma

b. Squamous cell carcinoma

c. Malignant keratocytoma

d. Malignant melanoma

After Ramon's skin came into contact with a poison ivy plant in biology lab, he developed a painful, itchy rash. However, after the skin of his colleague Cathy came into contact with snake venom in the lab, she developed no skin irritation. Poison ivy plants contain lipid-soluble oils, whereas snake venoms contain mostly water-soluble peptides. Explain why Ramon developed a rash, whereas Cathy did not.

Many antiaging skin creams contain collagen and hyaluronic acid. Manufacturers claim that the collagen and hyaluronic acid applied to the surface of the skin will be absorbed into the dermis, where they will be incorporated into dermal tissue.

Are these substances polar or nonpolar?

Many antiaging skin creams contain collagen and hyaluronic acid. Manufacturers claim that the collagen and hyaluronic acid applied to the surface of the skin will be absorbed into the dermis, where they will be incorporated into dermal tissue.

Predict whether or not these substances are likely to be absorbed by the epidermis.

Many antiaging skin creams contain collagen and hyaluronic acid. Manufacturers claim that the collagen and hyaluronic acid applied to the surface of the skin will be absorbed into the dermis, where they will be incorporated into dermal tissue.

Predict the effectiveness of the creams.

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?

(a) Porphyria

(b) EB

(c) Halitosis

(d) Vitiligo

Explain your answer.