Nails

Definition

Nails are keratinized, flattened structures found at the distal ends of the fingers and toes. They serve a protective function for the underlying skin and play a role in sensory perception and dexterity.

5 Must Know Facts For Your Next Test

1. Nails are composed primarily of keratin, a tough, fibrous protein that provides strength and protection.
2. The nail root, which is embedded in the skin, is the source of new nail growth and accounts for the majority of the nail's length.
3. The crescent-shaped whitish area at the base of the nail is called the lunula and is part of the visible nail matrix.
4. The nail fold, also known as the paronychium, is the skin that overlaps the sides and base of the nail plate.
5. Nails undergo a process of continuous growth, with the average adult fingernail growing approximately 3-4 millimeters per month.

Review Questions

• Explain the structure and function of the nail matrix in the context of nail growth and development.
  • The nail matrix is the area beneath the skin where the nail originates and grows. It is responsible for the production of new nail cells, which are pushed outward to form the visible nail plate. The nail matrix is the primary driver of nail growth, determining the shape, thickness, and curvature of the nail. As new cells are produced in the matrix, the older cells are pushed forward, resulting in the continuous growth of the nail from the proximal to the distal end.
• Describe the role of the nail bed in maintaining nail health and appearance.
  • The nail bed is the skin beneath the nail plate that supports and nourishes the nail. It provides a moist, protective environment for the nail to grow. The nail bed contains small blood vessels that supply nutrients and oxygen to the nail, contributing to its healthy appearance. Additionally, the nail bed contains specialized sensory receptors that allow for enhanced tactile sensation and dexterity in the fingers and toes.
• Analyze the significance of the nail fold (paronychium) in the overall structure and function of the nail.
  • The nail fold, or paronychium, is the skin that overlaps the sides and base of the nail plate. It serves to protect the nail matrix and nail bed from external factors, such as trauma and infection. The nail fold also helps to maintain the nail's shape and curvature by providing a secure attachment point for the nail plate. Furthermore, the nail fold plays a role in the overall aesthetic appearance of the nail, as it contributes to the defined edges and smooth transition from the skin to the nail.

Related terms

Nail Plate: The visible, hardened part of the nail that extends from the nail root to the free edge.

Nail Matrix: The area beneath the skin where the nail originates and grows.

Nail Bed: The skin beneath the nail plate that supports and nourishes the nail.