The sebaceous glands in the skin produce:

Correct Answer: B

Rationale: Sebaceous glands, found in the dermis near hair follicles, produce sebum, an oily substance. Sebum, a mix of lipids like triglycerides and wax esters, lubricates hair and skin, preventing dryness and offering minor antimicrobial protection. It's secreted via a holocrine process cells disintegrate to release it into follicles, then to the skin surface. Milk is produced by mammary glands, modified sweat glands, not sebaceous ones. Sweat comes from eccrine and apocrine glands, distinct from sebaceous function, with water and salts, not oil. Cerumen (earwax) is made by ceruminous glands in the ear canal, a specialized sebaceous type, but not typical skin sebaceous glands. Sebum's oily nature distinguishes it, supporting skin flexibility and waterproofing, a role confirmed by histological and physiological studies of gland activity, setting it apart from other secretions.

Correct Answer: A

Rationale: Sudiferous glands are sweat glands (eccrine and apocrine), secreting sweat, not sebum, which is an oily substance produced by sebaceous glands. Sebaceous glands correctly secrete oil (sebum) to lubricate skin and hair. Apocrine glands, a type of sudiferous gland, secrete sweat into hair follicles. Ceruminous glands in the ear canal secrete cerumen (earwax). The incorrect statement is that sudiferous glands secrete sebum, as their function is sweat production, a distinction clear in skin physiology, making this the error to identify.

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.