What do the apocrine glands of the skin secrete?

Correct Answer: D

Rationale: Apocrine glands, a type of sudiferous gland, secrete a thicker, milky sweat into hair follicles, often in areas like the armpits, triggered by stress or hormones. 'Apocrin' is a nonsense term. Cerumin (cerumen) is earwax from ceruminous glands. Milk comes from mammary glands, not apocrine. As sweat glands, apocrine glands differ from eccrine by their secretion site and composition, contributing to body odor when broken down by bacteria, making sweat the accurate secretion.

Correct Answer: D

Rationale: Full-thickness burns over 20% cause life-threatening fluid loss (dehydration) by destroying the waterproof skin barrier and allow infection by removing protection against pathogens. Vitamin D loss isn't acutely fatal. Thermoregulation fails but is secondary to fluid and infection risks. Skin doesn't significantly excrete lactic acid, urea, or uric acid (kidney roles). The dual crisis of fluid loss and infection vulnerability drives burn mortality, as clinical management focuses on fluids and antibiotics, making this the critical pair.

Correct Answer: B

Rationale: Normal flora (bacteria) reside on the epidermis, particularly the stratum corneum, the skin's surface exposed to the environment. The dermis, beneath, is internal and sterile unless breached. 'Microdermis' isn't a term; likely a typo. The hypodermis, deeper still, isn't a flora habitat. The epidermis, as the outermost layer, hosts these microbes, which thrive without penetrating living tissue, making it the correct location.

Correct Answer: C

Rationale: The skin regulates temperature via sweat glands and blood vessels, senses stimuli through receptors, and protects against pathogens with its physical barrier and immune cells, but hormone production isn't a primary skin function. Hormones like cortisol or testosterone are produced by endocrine glands (e.g., adrenals, gonads), not skin. While skin synthesizes vitamin D, a prohormone, this is a metabolic process, not hormone production in the endocrine sense. Temperature regulation involves sweating and vasodilation, sensation uses nerve endings, and pathogen protection relies on the stratum corneum and Langerhans cells. Hormone production's absence from skin's core roles distinguishes it as the incorrect function here.

Correct Answer: B

Rationale: The stratum corneum, the epidermis's outermost layer, is a barrier of dead, keratinized cells and lipids that prevents pathogen entry and water loss, protecting the body from infection and dehydration. Sensation involves dermal receptors, not this dead layer. Melanin is produced in the stratum basale, not corneum. Temperature regulation uses sweat and vessels, not this passive shield. Its tough, waterproof structure, constantly shedding to renew protection, defines its primary role, a cornerstone of skin defense.