What is the primary role of the stratum basale in the epidermis?

Correct Answer: B

Rationale: The stratum basale, the deepest epidermal layer, produces new skin cells via mitosis of basal keratinocytes, regenerating the epidermis as cells move up and keratinize. Sensation involves dermal receptors, temperature regulation uses sweat and vessels, and sebum secretion is from dermal glands, not the basale. Its role as the proliferative base, sustaining skin renewal, makes it the correct primary function.

Correct Answer: C

Rationale: Arrector pili muscles generate goosebumps by contracting to raise hairs, a response to cold or emotion, historically for insulation or threat display. Melanin is from melanocytes, 'ejecting hair shafts' misrepresents their action (though they move hairs), and temperature regulation is indirect, primarily vascular/sweat-based. Goosebumps are their hallmark effect, making this the primary function.

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.