Anatomy, Physiology, and Skin and Scalp Care
Build from cells upward
Cells form tissues, tissues form organs, organs form systems. For barbering, the systems that matter most are the skeletal (skull bones: frontal, parietal, temporal, occipital, zygomatic, maxilla, mandible), the muscular (frontalis, occipitalis, temporalis, masseter, sternocleidomastoid, trapezius, platysma), the nervous (the trigeminal nerve's ophthalmic, maxillary, and mandibular branches carry sensation to the face and scalp; the facial nerve is the motor nerve for expression), and the circulatory (common carotid dividing into internal and external; facial and superficial temporal arteries supplying the face and scalp).
Skin and hair
Epidermis, dermis, subcutaneous layer. Hair has a follicle, bulb, papilla, sebaceous gland, and arrector pili muscle. Growth cycles are anagen (growth), catagen (transition), and telogen (rest). Hair types are lanugo, vellus, and terminal. Density, texture, porosity, and elasticity determine how hair responds to chemical and thermal services - test before you treat.
Scalp and skin care within a barber's role
Recognize normal, dry, oily, and combination skin and common scalp conditions such as flaking, seborrheic-type irritation, and fungal infection. A barber recognizes and refers; a barber does not diagnose or treat disease. Contraindications for chemical or heat services include broken or inflamed skin, open lesions, recent chemical services, and known sensitivities. Patch-test and strand-test when the product requires it.
Traps
- Swapping the trigeminal (sensory) and facial (motor) nerves.
- Mixing vellus and terminal hair, or the cycle stages.
- Believing massage is always safe - avoid over inflamed, swollen, or infected areas.
- Treating flaking scalp as a styling problem instead of referring.
Worked example: A client with an itchy, ring-shaped scaly patch on the scalp. Correct response: do not service that area, do not diagnose, recommend a physician, and disinfect all tools that touched the client.