Nails have been a statement of fashion since the dawn of time. They’re painted, shaped and conjugated with accessories to put forward an expression of fashion and style. Nails are one of the few parts of the body that can be “glammed up”, along with hair. They are also the parts of the body which, when cut, do not hurt the individual – something that cannot be said about the other parts of the body.
What are nails made up of?
The mechanism of growing of nails is rather simply – nails actually grow underneath our skin behind the actual ‘nails’ that we see. The old cells are pushed from under the skin to make place for the new cells – thus, the old cells create the nail bed that is externally observed. This is the reason attributed to the fact that when nails are cut, it doesn’t pain since the cells in it are dead and no pain receptors are ignited during the event.
Nails are made up of a protein called KERATIN, which is tough and resilient in nature. It is highly different from the protein bone are formed of, i.e., COLLAGEN. Keratin, also known as alpha-keratin, is a FIBROUS PROTEIN, found only in vertebrates. It is also found in the structure of hair, but the type of bonds involved in hair keratin are different than those found in nails.
Evolutionarily, nails have evolved from claws, talons and hooves that are found in other animals – especially for the purpose of defense and climbing. In humans, however, these have become somewhat less functional and useful. It’s only function in humans is to protect the fingertip and the surrounding tissue. We often notice that the skin under the nails are extremely sensitive (in case a nail breaks) and that is why nails are required to protect them from said damage due to their sensitivity. A proposed function of the nail is to enhance ‘precision grip’, referring to the fact that the decreased surface area of the nail can precisely latch onto a minute thing more effectively than the fingertip can. This is demonstrated when a nail is to be removed – nails are preferred to pull it out than the finger because of its smaller surface area.
What are the parts of a nail?
- The Matrix
The Matrix refers to the tissues which possess keratin and lies under the actual nail we see. It contains nerves and blood vessels, hence when nail attached to the skin breaks, a sensitive layer of tissue is observed below, which needs to be projected from further injury. Since the matrix is the tissue to be protected, it produces the cells which forms the nail plate by pushing out the old cells outward while producing new ones under the skin, inward.
The old cells, being translucent, cause visibility of the blood vessels below, thus giving a pink tinge to the nails. As the nail grows longer, it becomes more opaque and losing the pink tinge as there are no blood vessels below it.
Another part of the nail plate is the lunula, observed as a crescent-shaped structure at the base of the nail plate.
- Nail Bed
The nail bed is present under the nail plate and is composed of two parts – the dermis and the epidermis. Both of these are types of skin but differ in the structures present in them. The dermis has capillaries and glands, while the epidermis composes the fingertip.
- Nail Root
The nail root originates from the matrix cells and is at the base of the nail underneath the skin.
A cuticle is a thin layer of tissue near the base of the nail. It is observed as a semi-circular layer, which is dead. It is popularly removed during a manicure. The living part of the cuticle is called the eponychium, which is not disturbed during a manicure due to its sensitive nature. Hurting the eponychium can cause pain since it contains pain receptors.
It the living skin around the nail which is a living soft tissue. Injury to it can cause bleeding and damage to the nail itself.
- Free margin
The free margin is the outward edge of the nail which often breaks and needs to be filed (i.e., shaped) to avoid sharp edges.
Along with nails being the most popular and easy form of fashion, biting them is the most common nervous habit. It is recommended that one does not bite their nails since there may be deposition of dust and bacteria under the nails. By biting them, these plausible pathogens gain direct access to the mouth and can infect the subsequent systems of the body here on forward.
The white spots or lines observed were considered to be an indication of calcium deficiency, but are in fact caused due to minor injuries to the nail bed and the underlying skin. It is thus recommended that nail hygiene be maintained with nail beauty and length.