Nail Anatomy 101

The nail is the plate that grows at the back (near the tip or the terminal phalanges) of your fingers and toes. It is the same as the claw of an animal. It is a translucent, keratinous structure that contains epithelial cells. Those cells advance when new cells are added at the bottom part of the nail, thus making it longer. Meanwhile, keratin (protein) is responsible for making it tough and hard. The nail is purposely placed at the fingertips to protect them and aids in thermo regulation.

Parts of a Nail

Nail root- It is formed by the actively growing tissues called “matrix”. It is situated at the nail sinus.
Nail Bed- The layer of skin underneath the nail plate is the nail bed. It consists of blood vessels and nerves responsible for delivering nutrients to the nails, making it grow longer. It slides upward whenever there are new cells emerging from the bottom of the plate.
Nail Plate- The nail plate extends from the proximal nail fold and extends on the sides of lateral nail folds or the paronychium. The nail plate is made up of keratinized squamous cells that are loosely attached to the germinal matrix but strongly bound to the sterile matrix. Too many fancy terms here eh? Don’t worry. We have a simpler explanation of these terms below.

  • Proximal and Lateral Nail Fold- sides of the nails
  • Distal edge- the cutting edge of the nail/ anterior margin
  • Eponychium or Cuticle – It is the hardened outermost layer of the skin.
  • Lunula – It is the known as the half-moon shaped arc from the proximal to distal part of the nail. Lunula is located at the distal part of the germinal matrix. It is whiter compared to the rest of the nail plate because it is loosely attached to the nail bed, which contains the blood vessel that gives that pinkish colour.
  • Hyponychium- It is the epithelium part of the nail bed.

Nail Functions

The main function of a fingernail is to protect the fingertip or distal phalanx. The fingertip is prone to injuries because it is made up of soft tissues, making it prone to damage. It serves as an additional thermo regulator for the body’s defence against cold temperature. It also complements the sensitivity of the fingertip in terms of touching or feeling an object. Lastly, it contributes to a stronger hand grip. Your toenails also protect the tip of your toes.

Long Long Nails

Like a tree, the nails grow from the roots where lunula is located. The group of cells formed from the roots are added at the bottom of the nail. The nail bed then slides upward and pushes the old cells towards the tip. The reason why both lunula and the tip of your nail are white is because they are loosely attached to the nail bed. When there’s lack of blood vessels and blood circulation, the nail becomes white. That is also why corpses have pale to white nails. There is no circulation blood present.