The protein that gives the skin color is:

Correct Answer: B

Rationale: The correct answer is B: melanin. Melanin is the pigment responsible for giving the skin its color. It is produced by melanocytes in the skin's epidermis. Melanin protects the skin from harmful UV radiation and determines the skin's color. Keratin (A) is a structural protein found in the skin, hair, and nails. Collagen (C) is a protein that provides structure and elasticity to the skin. Elastin (D) is a protein that helps the skin to stretch and recoil. However, neither collagen nor elastin are responsible for skin color. The presence of melanin is what primarily determines an individual's skin color.

Correct Answer: C

Rationale: The correct answer is C. In a cold environment, vasoconstriction in the dermis does not keep the skin warm. Vasoconstriction reduces blood flow to the skin, which actually decreases heat loss and helps conserve body heat. This is a physiological response to cold temperatures to maintain core body temperature. Choices A, B, and D are incorrect because they accurately describe the functions of the skin and body temperature regulation. Vasodilation in the dermis promotes heat loss in a warm environment, eccrine glands increase sweat secretion as environmental temperature rises to cool the body through evaporation, and pilomotor muscles contract to provide insulation by trapping air close to the skin in cold conditions.

Correct Answer: D

Rationale: The correct answer is D: Thinning and atrophy of the skin. Prolonged use of corticosteroid ointment can lead to skin thinning and atrophy due to its ability to inhibit collagen synthesis and promote breakdown of skin proteins. This can result in fragile, easily bruised skin. Desensitization and nerve damage (Choice A) are not common side effects of corticosteroid ointment. Formation of petechiae (Choice B) is not typically associated with corticosteroid use. Avascularization of the affected skin (Choice C) is not a known consequence of prolonged corticosteroid use.

Correct Answer: C

Rationale: The correct answer is C: 8,400 mL. The Parkland/Baxter formula for fluid resuscitation in burn patients is 4 mL x %TBSA x weight in kg. In this case, it would be 4 mL x 60% x 70 kg = 1,680 mL for the first 8 hours. Since the burn occurred at 10:00 AM, by 6:00 PM, 8 hours have passed. Therefore, the total amount of lactated Ringer solution to be infused by 6:00 PM would be 1,680 mL x 5 = 8,400 mL. Choice A (5,200 mL) is incorrect as it does not take into account the correct formula for fluid resuscitation in burn patients. Choice B (7,470 mL) is incorrect as it is not the total amount of fluid needed based on the Parkland/Baxter formula. Choice D (16,800 mL) is

Correct Answer: A

Rationale: The correct answer is A because administering PCA allows the client to self-administer pain medication within predetermined safety limits, promoting autonomy and timely pain relief. Choice B is incorrect as the amount of medication is preset by healthcare providers to prevent overdose. Choice C is incorrect as PCA involves controlled, consistent dosages. Choice D is incorrect as the nurse still monitors the client's pain levels and response to medication despite self-administration.