Which part of a growing hair consists of actively dividing cells?

The germinal matrix is the part of the hair follicle where actively dividing cells are located. This area is situated at the base of the hair bulb and is crucial for the growth of hair. The cells in the germinal matrix undergo mitosis, contributing to the production of new hair fibers as well as the elongation of the existing hair shaft.

As these cells divide and differentiate, they move up through the hair follicle, undergoing keratinization to form the various layers of the hair structure. The health and vitality of the germinal matrix are essential for proper hair growth and development, making it a key focus in hair biology.

In contrast, while the hair bulb is the enlarged structure at the base of the hair follicle that houses the germinal matrix, it does not specifically refer to the area of active cell division. The cortex represents the fibrous protein of the hair shaft that provides strength and structure, while the dermal papilla, located beneath the germinal matrix, contains blood vessels and connective tissue that supply nutrients to the hair follicle but do not contain the actively dividing cells themselves.