Anatomy and Physiology
What this domain tests
Anatomy and physiology items connect skin structure to treatment response: layers, barrier, glands, circulation, lymphatics, wound healing, and endocrine effects. Expect questions on why a treatment is contraindicated or why a product stings.
Core rules
- Epidermis: stratum corneum for barrier, granulosum, spinosum, and basale for mitosis and melanocytes. Dermis: papillary and reticular layers with collagen, elastin, fibroblasts, blood vessels, nerves, and glands.
- The acid mantle and intercellular lipids limit water loss; over-exfoliation raises transepidermal water loss and causes stinging, tightness, and erythema.
- Sebaceous glands are androgen-sensitive and concentrate on the face, chest, and back. Eccrine sweat glands regulate temperature; apocrine glands are odor-associated.
- Wound healing proceeds through hemostasis, inflammation, proliferation with granulation and collagen, and remodeling. Collagen remodeling takes months.
- Lymphatic drainage moves toward cervical, submandibular, and preauricular nodes; massage is light and proximal.
Worked example
A client had a medium-depth peel five days ago and now has tight, pink skin with mild flaking. She asks for strong facial massage and a scrub. Decline both and provide barrier repair and sunscreen. The reasoning: the skin is still in the inflammatory or proliferative phase; mechanical irritation and heat increase risk of post-inflammatory hyperpigmentation and barrier injury.
Traps
Do not confuse sebaceous and sweat glands. Do not describe the dermis as avascular. Do not massage toward the heart on the face without following lymphatic pathways. Do not assume flaking means the barrier is ready for more exfoliation.