White lines on the fingernails can mean a variety of things. The most common is caused by trauma to the nail (hitting it on things), but it can also be due to a zinc deficiency. If it is caused by lack of zinc eat plenty of red meat, poultry, and nuts.
He sometimes paints them black, and other colours too, but the nails themselves are the regular clear, translucent nail color ;)
Nails (and finger nails) have volume.
Finger nails are made of a protein called keratin.
No one invented finger nails.
Actually, finger nails contain protein (called "keratin").
By system, you mean category.. I'm not sure if you mean finger nails or like tool nails, so I'll give you both. Finger nails: Body parts Tool nails: Hardware
Finger nails (and toe nails) are made of keratin.
Healthy nails are usually a consistent pink color. They are hard and moist enough that they do not break or split too easily. The edges of your nails should stop while still on the finger, and the nails should be firmly attached to your nail beds. Healthy nails are smooth, and the texture shouldn't include things like Beau's lines, which are deep grooved lines from side to side of the fingernail. Beau's lines are a sign of infection or Kawasaki disease. Nails should also run straight out of the finger tip, as opposed to curving out (koilonychias: a sign of anemia).
yes
yes
Nails
I believe they grow faster.