Final answer:
Fine hair may lack a medulla, the central core of the hair, but will have a cuticle layer and a specific hair texture, determined by the hair follicle's shape and the cortex's structure.
Step-by-step explanation:
Fine hair may not contain a medulla, which is the innermost layer of the hair. The parts of a hair shaft include the cuticle, the cortex, and optionally, the medulla. Fine or very light hair, such as lanugo, which is the fine, unpigmented hair that covers the body before birth, might not have a medulla. However, the fine hair definitely has a cuticle layer and a specific hair texture determined by the shape of the hair follicle and the structure of the cortex.
The hair matrix, containing a layer of basal cells, is the growth center of the hair from where the cells divide and push out to form the hair shaft. The medulla, when present, is formed from the hair matrix and gives hair its full structure, but it's not always found in fine hair. The cuticle is the protective outer layer that all hair has, and it's not correct to say that fine hair lacks a cuticle. Lastly, lanugo is a type of hair that is present on the fetus and not a part of the hair itself.