Final answer:
The cuticle is the outermost layer of the hair shaft, and its main function is to protect the hair, not to initiate hair growth or regulate pigment production.
Step-by-step explanation:
The cuticle is the outermost layer of the hair shaft, not the innermost. It is composed of hard, keratinized cells, originating from the hair matrix, and its primary function is to protect the hair shaft by forming a hard layer around the more delicate internal structures of the hair. By being the external layer, it plays a crucial role in preventing damage to the hair's inner layers.
It's important to note that the medulla is the innermost zone of the hair, not the cuticle. Also, functions such as regulating pigment production are handled by melanocytes in the hair follicle, not the cuticle. Initiation of hair growth occurs at the hair matrix, a layer of basal cells at the base of the hair follicle; the cuticle does not play a direct role in initiating growth.