Horizontal sectioning of scalp, a thin skin, can be used to demonstrate the cross section of hair.
Human Scalp Horizontal section. (TM: 25x, picture taken with a Zeiss F2.5/0.08 on Sony A7ii)Cross section of hair. Annotated version here. (TM: 400x, picture taken with a Zeiss F40/0.8 on Sony A7ii)