A new nail forms through a continuous process of cell division and keratinization at the nail matrix, located at the base of the nail.
The Nail Formation Process Explained:
The process of nail formation is a fascinating example of specialized cell growth and differentiation. It can be broken down into several key steps:
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Nail Matrix Activity: The nail matrix, found under the proximal nail fold (the skin at the base of the nail), is the engine room of nail growth. This is where specialized cells called matrix cells or keratocytes actively divide.
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Cell Division: These matrix cells rapidly proliferate through mitosis. This constant cell division creates new cells that push older cells forward.
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Keratinization: As the newly formed cells are pushed forward, they undergo a process called keratinization. Keratin is a tough, fibrous protein that also makes up hair and the outer layer of skin. During keratinization, the cells become flattened and hardened as they fill with keratin.
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Nail Plate Formation: The hardened, keratinized cells form the nail plate, the visible part of the nail. This plate is gradually pushed forward over the nail bed (the skin underneath the nail plate). The lunula, the half-moon shaped area at the base of the nail, is the visible part of the matrix.
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Continuous Growth: This cycle of cell division, keratinization, and forward movement is continuous, resulting in the gradual growth of the nail. Because new cells are always being added at the base, the nail appears to grow from the base towards the fingertip.
In essence, new nail growth happens only at the base of the nail, where new cells are created. These cells are then pushed forward as more new cells form behind them, thus lengthening the visible nail.