People with full thickness burns to more than 20% of their body are in a life-threatening situation. This is due to which of the following?

Correct Answer: D

Rationale: Full-thickness burns over 20% destroy the epidermis and dermis, removing the waterproof stratum corneum, causing rapid water loss leading to dehydration and shock a primary life threat. Thermoregulation is impaired but secondary to fluid loss. Vitamin D loss isn't immediately fatal. Urea and uric acid excretion is minimal via skin (mostly kidneys), not a key issue. Water loss, a critical consequence of losing the skin barrier, is the dominant factor, as evidenced by burn treatment prioritizing fluid replacement.

Correct Answer: B

Rationale: The stratum corneum consists of dead, keratinized cells, forming a protective barrier shed through abrasion correct. Cell division occurs in the stratum basale, not corneum. Collagen, elastin, and reticular fibers are dermal, not in the avascular corneum. Sensory receptors reside in the dermis or deeper epidermis, not the dead corneum. Its dead cell composition is its defining trait, making this the accurate statement.

Correct Answer: C

Rationale: The hypodermis, also called subcutaneous tissue, contains adipose tissue that insulates the body against heat loss and stores energy as fat reserves. The epidermis is a thin, avascular layer of epithelial cells, lacking fat. The dermis has connective tissue, glands, and vessels, but not significant adipose. 'Subcutaneous tissue' is synonymous with hypodermis, reinforcing its role. The hypodermis's fat content, cushioning organs and providing a calorie reserve, distinguishes it from the skin's upper layers, making it the correct answer.

Correct Answer: B

Rationale: Pacinian corpuscles, deep pressure and vibration sensors, are located in the dermis, often near its border with the hypodermis, within the reticular layer. The epidermis, avascular and superficial, lacks such receptors. The hypodermis (subcutaneous tissue) may contain some, but they're primarily dermal, integrated with nerve networks there. The dermis's role as the sensory and structural layer, housing various receptors, makes it the correct location for these lamellated corpuscles.

Correct Answer: A

Rationale: The subcutaneous tissue (hypodermis) attaches the skin to underlying muscles and bones via loose connective tissue and fat, allowing mobility while securing position. UV protection is the epidermis's role via melanin. Sweat production occurs in the dermis, not hypodermis. Hair follicle nourishment is dermal, via blood and sebum. The hypodermis's anchoring function, cushioning and connecting, makes attachment its primary purpose, per anatomical structure.