The skin's ability to regenerate and repair itself is primarily attributed to the presence of which cells?

Correct Answer: B

Rationale: Fibroblasts in the dermis produce collagen and extracellular matrix during wound healing, driving repair and regeneration by rebuilding tissue post-injury. Melanocytes make melanin, not repair tissue. Macrophages clear debris and fight infection, aiding but not leading regeneration. Adipocytes store fat, not regenerate skin. Fibroblasts' role in scar formation and dermal restoration is central to skin repair, making them the key cells.

Correct Answer: D

Rationale: Diabetic wounds, particularly diabetic foot ulcers, are commonly located on the plantar aspect of the foot, including the metatarsal heads (met heads) and heel, due to neuropathy, poor circulation, and repetitive pressure in diabetic patients. Arterial wounds are typically found on the toes or shins due to poor arterial blood supply, not specifically the plantar surface. Plantar is a location (bottom of the foot), not a wound type, so it doesn't fit as a category. Venous wounds are usually around the ankles or lower legs due to venous insufficiency. Diabetic wounds align perfectly with the described locations because of the predisposition to pressure points and poor healing, making it the correct choice.

Correct Answer: B

Rationale: An emollient is a substance that softens and moisturizes the skin, often relieving itching, thus having an antipruritic (anti-itch) effect. Pruritic means causing itching, the opposite of an emollient's purpose. Rupture refers to breaking or tearing, unrelated to emollients. Impetigo is a bacterial skin infection, not an effect. Emollients, like lotions or creams, are used in dermatology to hydrate skin and reduce irritation, directly linking to an antipruritic effect, making this the correct choice.

Correct Answer: D

Rationale: Urticaria, commonly known as hives, is a skin condition characterized by raised, itchy welts due to allergic or other triggers. Keloids are overgrown scars, not hives. Seborrhea involves oily, scaly skin, unrelated to hives. Eczema causes itchy, inflamed skin but typically as patches, not distinct welts like hives. Urticaria specifically matches the definition of hives, with its hallmark transient, raised lesions, making it the correct disease.

Correct Answer: D

Rationale: The epidermis consists of multiple layers, but not all are present in every region of the body. The stratum lucidum, a thin, translucent layer of dead cells, is found only in thick skin, such as the palms and soles, where it lies between the stratum granulosum and stratum corneum. It is absent in thin skin, which covers the head, torso, and most of the body, where the epidermis transitions directly from the stratum granulosum to the stratum corneum. The stratum spinosum provides strength, the stratum corneum serves as the protective outer barrier, and the stratum granulosum aids in keratinization all present in both thick and thin skin. The stratum germinativum, though not an option here, is universal as the basal layer. The absence of the stratum lucidum in thin skin reflects its adaptation to less mechanical stress, unlike the thickened, friction-resistant skin of the hands and feet. Thus, the layer missing from the head and torso is the stratum lucidum.