Where are sebaceous glands found?

Correct Answer: C

Rationale: Sebaceous glands are located in the dermis, the thick layer of skin beneath the epidermis, where they produce sebum, an oily substance that lubricates hair and skin. They are typically associated with hair follicles, which are embedded in the dermis, and secrete sebum into the follicle to reach the surface. The digestive system is unrelated to skin glands, ruling it out entirely. The hypodermis, or subcutaneous layer, contains fat and connective tissue, not sebaceous glands. The stratum corneum, the outermost epidermal layer, consists of dead, keratinized cells and lacks glands or living structures. Anatomical studies of skin consistently place sebaceous glands in the dermis, making this the correct location due to their functional and structural integration with dermal components like hair follicles and blood vessels.

Correct Answer: A

Rationale: Transdermal administration involves applying a drug (e.g., via a patch) to the skin for systemic absorption into the bloodstream, affecting the whole body, like fentanyl patches. Topical administration targets local skin effects, like antibiotic creams. Intradermal injections deliver into the dermis, not surface application. Subcutaneous administration goes beneath the skin via injection. 'Trans' (across) indicates crossing the skin barrier for systemic action, a method reliant on the skin's permeability, making this the correct term.

Correct Answer: D

Rationale: Skin functions include producing melanin (via melanocytes) for UV protection, secreting sebum (via sebaceous glands) to lubricate, and minimizing water loss via the stratum corneum's barrier. Storing fat occurs in the hypodermis, not skin. Bile excretion is a liver function, not skin. Keratin production and immunity (via Langerhans cells) are true, but lymphocytes are made in lymphoid organs, not skin. The trio of melanin, sebum, and water retention reflects core integumentary roles, making this the accurate set.

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: B

Rationale: The epidermis is the outermost skin layer, encompassing sublayers like the stratum corneum, serving as the body's primary barrier. The dermis lies beneath it, supporting with connective tissue and glands. The stratum lucidum is an epidermal sublayer below the corneum in thick skin. The reticular dermal layer is deep in the dermis. As the topmost structure, the epidermis literally 'over the dermis' is the correct outermost layer, per standard skin anatomy.