Simplify the following text for a Grade 11 native English-speaking person.
Original: The internal root sheath is composed of three layers , Henle 's layer , Huxley 's layer , and an internal cuticle that is continuous with the outermost layer of the hair fiber .
Simplified: The internal root sheath is composed of three layers , Henle 's layer , Huxley 's layer , and an internal cuticle that is continuous with the outer layer of the hair fiber .