How often should the free edge of the nail be trimmed outer layer of skin that is responsible for the production of melanin and keratin keratin 2. a protein substance necessary for healthy skin, hair, and nails dermis 3. the inner layer of skin that contains hair follicles, blood vessels, and sebaceous glands earache 4. the result of sebum being trapped in a follicle with a piece of dirt or bacteria cochlea 5. the results of sweat being allowed to sit on bacteria-crowded areas of the skin acne 6. the best means of prevention for body odor and acne ossicles 7. a thin membrane, dividing the outer ear from the middle ear, which moves the ossicles wax 8. channels sound to the eardrum eardrum 9. protects the eardrum from dirt ear plugs 10. small bones in the middle ear that transfer sound waves to the inner ear ear canal 11. converts sound waves into electrochemical impulses, which are transmitted to the brain epidermis 12. caused by sinus infection or another illness affecting the nose or mouth ear drops 13. a safe treatment for wax build-up washing 14. appropriate protection from loud noises body odor