Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders
Anatomy and physiology at the level tested
Cells build tissues, tissues build organs, organs build the eleven body systems. Focus on the integumentary, skeletal, muscular, nervous and circulatory systems. Bones: cranium, mandible, maxillae, zygomatic. Muscles of expression and mastication: frontalis, orbicularis oculi, masseter, temporalis, platysma, trapezius. Nerves: fifth cranial (trigeminal) and seventh cranial (facial); greater occipital. Arteries: common carotid, then the temporal, occipital and facial branches.
Skin has epidermis, dermis and subcutaneous layers; the acid mantle sits near pH 4.5–5.5. Hair has cuticle, cortex and medulla - the medulla is not present in fine or very light hair, and the cortex provides strength, elasticity and pigment. The follicle holds the bulb, papilla, sebaceous gland and arrector pili. Nail: plate, bed, matrix (the lunula is the visible portion), eponychium, hyponychium, sidewall, free edge.
Traps
- Acids contract and close the cuticle; alkalis swell and open it. Questions reverse this.
- Physical change (melting, freezing) versus chemical change (color, oxidation, reduction).
- Disorders you may serve versus those you must refer: tinea, impetigo, conjunctivitis, pediculosis, furuncles and carbuncles are all refer-out. Use ABCDE (asymmetry, border, color, diameter, evolving) for suspicious lesions.
Rule of thumb
pH 7 is neutral; every step below 7 is acidic, every step above is alkaline, and each whole number is a tenfold change in strength.