Nail Anatomy

Intro

Healthy nails are smooth, shiny, and translucent pink colored. They also have a normal growth pattern. Unhealthy nails can have disorders and result in abnormal growth.
The technical term for nail is “onyx”. Nails are considered part of the skin; they are made up of keratin, like the skin and hair. But nails are a harder form of keratin than skin and hair. They help to protect and grasp.
The average rate of growth for adult nails is 1/8” per month. Toenails grow even slower. Nails can replace themselves within 3-4 months. They do grow quicker in the summer than the winter. The nail on the middle finger grows the fastest, and the nail on the thumb the slowest.

Parts of the Fingernail:

1. Nail Plate: Main part of the nail that is attached to the skin at the top layer of the finger. Although it looks like one piece, it is actually formed in layers.
2. Nail Root: This is where the nail growth begins. It is embedded under the skin at the base of the nail.
3. Free Edge: The part of the nail that extends beyond the fingertip.

Beneath the Fingernail:

1. Nail Bed: Skin beneath the nail plate that is supplied with blood and contains nerves.
2. Nail Matrix: This part contains nerves with lymph blood vessels that produce the nail cells and control the rate of growth. It is found under the nail root. If this part is injured it can cause permanent damage and cause irregular growth patterns.
3. Lunula: Light colored, half moon shaped part of the nail at the base. This is where the nail matrix contacts the nail bed underneath.

Skin Around the Fingernail:

1. Cuticle: The overlapping skin around the nail. Normal shape is loose and pliable.
2. Nail Fold/Mantle: Deep fold of skin at the base of the nail where the nail root is embedded.
3. Nail Grooves/Sidewalls: Slits or tracks in the nail bed at the sides of the nail that the nail grows in.
4. Nail Wall: Skin outside of the nail above the grooves.
5. Eponychium: Thin line at base of nail that extends from the nail wall to the nail plate.
6. Paranychium: Skin that surrounds the entire nail.
7. Hyponychium: Part of the skin under the free edge of the nail.