Anatomy, Physiology, and Skin Care
What this domain tests
This domain tests the structures you work on and the safety boundaries they create: skin layers, hair structure and growth cycles, facial bones, muscles, nerves, blood supply, and skin conditions that change or prohibit a service.
Core rules and concepts
- Skin layers. The epidermis is the protective outer layer; the dermis contains follicles, glands, and vessels; the subcutaneous layer cushions and insulates. The skin is a barrier, so broken skin changes your service plan.
- Hair structure. The follicle houses the hair bulb and papilla. The shaft has a cuticle, cortex, and sometimes a medulla. The sebaceous gland lubricates the follicle.
- Growth cycle. Anagen is the growing phase, catagen is transitional, and telogen is resting before shedding. Hair length and shedding patterns depend on this cycle.
- Bones and muscles. Know the frontal, parietal, temporal, occipital, zygomatic, maxilla, and mandible. Facial muscles include frontalis, temporalis, masseter, orbicularis oculi, and occipitalis.
- Nerves and blood. The trigeminal nerve carries sensation from the face; the facial nerve supplies motor control. The external carotid artery and its branches, including the superficial temporal artery, supply the face and scalp.
- Skin care boundaries. Identify dry, oily, combination, and sensitive skin. Do not treat inflamed, broken, or infected skin; refer suspicious lesions.
Worked example
A client has dry, flaky patches on the scalp and wants a tight fade with a razor outline. Reason it out: flaking alone may be dryness or dandruff, but redness, crusting, or broken skin suggests a condition you should not irritate. Do not use a razor on inflamed areas. Use clippers carefully, avoid harsh products, and refer if the scalp is inflamed or the condition is unclear.
Traps that cost marks
Reversing the trigeminal and facial nerve functions; placing the masseter in the wrong area; calling all flakes dandruff; and massaging or shaving over inflamed or broken skin.