Which of the following lists layers of the integument in the order from most superficial first, to deep?

Correct Answer: B

Rationale: The integument includes the epidermis and dermis. The correct order is epidermis (outermost), then the dermis's papillary layer (superficial), followed by the reticular layer (deeper). Hypodermis isn't part of the integument. Listing dermis before epidermal layers reverses the order, and grouping corneum and germinativum within epidermis ignores the dermis's structure. The sequence epidermis, papillary, reticular accurately reflects the skin's layered anatomy from surface to depth.

Correct Answer: A

Rationale: Skin waterproofs via the stratum corneum, produces vitamin D with UV exposure, and aids immunity via Langerhans cells, but fat storage occurs in the hypodermis (subcutaneous layer), not the integument (epidermis and dermis). The hypodermis's role in energy storage is distinct from skin functions, which focus on protection, synthesis, and sensation. Fat storage's exclusion from the integument proper, per anatomical definition, makes this the non-function.

Correct Answer: A

Rationale: Merkel discs (touch), nociceptors (pain), and Pacinian corpuscles (pressure) are sensory receptors in the skin, detecting environmental stimuli. The reticular dermal layer, the deeper dermis part, is connective tissue with collagen and elastin, not a receptor. It supports receptors but doesn't sense, distinguishing it from the others, which are specialized nerve endings or structures, making it the non-receptor.

Correct Answer: B

Rationale: Sebaceous glands, located in the dermis, primarily produce sebum, an oily substance that lubricates skin and hair, preventing dryness and aiding waterproofing. Sweat production is the role of sudiferous glands (eccrine and apocrine), not sebaceous. Melanin comes from melanocytes in the epidermis, not glands. Collagen is synthesized by fibroblasts in the dermis, not secreted by glands. Sebum's lipid-rich composition, secreted into hair follicles, distinguishes sebaceous glands' function, essential for skin and hair maintenance, making this the accurate primary role.

Correct Answer: C

Rationale: Collagen and elastin fibers in the dermis provide strength and elasticity: collagen, abundant in the reticular layer, resists stretching, while elastin allows recoil, maintaining skin's resilience. Blood vessels supply nutrients, not structure. Sweat glands regulate temperature, not toughness. Nerve endings sense stimuli, not support. These fibers, produced by fibroblasts, form the dermis's extracellular matrix, critical for skin's durability and flexibility, making them the key components.