Anatomy and Physiology of the Skin and Body Systems
Anatomy items on the esthetics exam are applied, not memorized in isolation: they ask you to connect a structure to a service. Expect layers and cells of the skin, glands, hair follicle anatomy, facial muscles, bones, nerves, and circulation.
Layers and cells
- Epidermis: stratum corneum (barrier), stratum lucidum (palms and soles only), granulosum, spinosum, basale (single dividing layer). Keratinocytes form the barrier; melanocytes in the basale produce pigment; Langerhans cells are immune sentinels; Merkel cells register touch.
- Dermis: papillary layer (capillaries, touch receptors) and reticular layer (collagen, elastin, glands, follicles).
- Subcutaneous layer: fat and fascia, providing insulation and support.
Glands and follicles
Sebaceous glands attach to hair follicles and secrete sebum. Eccrine glands are found almost everywhere and produce sweat; apocrine glands open into follicles in the axillae and groin. The arrector pili is smooth muscle; the follicle has a bulb, papilla, and root sheath.
Muscles and bones used in service
Frontalis raises the brow; orbicularis oculi closes the eye; zygomaticus raises the mouth; masseter is a chewing muscle of the jaw; platysma tenses the neck. Facial bones to know include the frontal, zygomatic, maxilla, mandible, and nasal bones.
Worked example
A question asks which tissue a massage movement affects most directly. Effleurage works on the superficial tissue and circulation of the dermis and subcutaneous layer - it does not stretch the stratum corneum or change bone. Reasoning from structure to function gives the answer.
Traps
Placing melanocytes in the dermis. Calling the papillary layer deep. Treating massage as a way to "move lymph" without regard to direction toward the nodes and the contraindications you will see in Domain 7.