Humans have nails in both hands and feet, and these flat versions of claws are essential for human function. They enable humans to dig, climb, scratch, and grasp, and act as protective plates that protect from injuries. Moreover, nails also enhance sensation, allowing the body to process huge amounts of information when touched. Similarly, nails act as counterforce against the forces that humans exert on their hands and feet. Let’s take a closer look at the human nail!
Onychodermal band
The onychodermal nail band is a thin white line that marks the distal end of the nail plate. Its proximal border is immediately distal to the nail bed’s distal limit. The distal boundary is the free edge of the nail plate, which would otherwise project onto the epidermis. Most fingernails have a band between the hyponychium and the free edge.
Onychcholysis occurs when the normal nail adhesive properties break down. This can occur due to trauma, prolonged exposure to water, or contact irritants, including nail polish or other cosmetics. Systemic medications have also been linked to onycholysis. Although onycholysis typically presents as an asymptomatic condition, it is a cause for concern, and can result in nail plate separation. Fortunately, it can be treated and is a cosmetic concern.
Onychodermal bands are 1-1.5 mm thick and form the first barrier to the nail bed. Their function is to prevent materials from penetrating beneath the nail plate. If they break, the nail plate may lift and the nail bed will become unusable. In some cases, this can lead to permanent changes in the structure of the nail bed tissue. While it is difficult to treat this condition, it is possible to improve it by addressing underlying malignancy.
Cuticle
The cuticle is the white, flaky skin that covers the base of the nail. It is composed of eponychium, the white layer of dead skin beneath the nail fold. A sticky substance attaches these cells to the nail plate and the framing of keratinised epidermis above. The cuticle is a key part of the nail’s seal. Cutting or peeling it off can cause infection or injury.
There are many diseases that can affect the cuticle. Nail bed infection, poor blood circulation, or heart conditions may cause nail splitting around the cuticle. Bleeding under the nail, or dark purplish spots, can indicate a bacterial infection. Other symptoms may be related to the nail plate itself, including overgrowth, infection, or fungus. This condition can also be caused by a broken nail growth into flesh.
Lunula
The lunula is a small, white spot located at the base of a fingernail. Changes in this area may be caused by trauma, excessive manicuring, or other factors. The lunula may also become pink or red, which may indicate a more serious underlying issue. In addition, missing lunulas can also indicate a lack of nutrition or anaemia.
While there are many possible causes, researchers don’t understand why the lunula takes up a large portion of a fingernail. Although this portion of the nail may not be noticeable, it may indicate that a person is lacking oxygen. In such a case, it may be necessary to cut back on work. In addition, the appearance of a pink or red lunula can indicate a condition involving the heart or lungs. If the nail bed is dark or discolored, it might be a sign that the person has an underlying condition.
When the lunula is missing or discoloured, it is important to see a doctor for a proper diagnosis. The overall symptoms of the patient will determine the appropriate course of action. The doctor will also order medical tests to rule out other potential conditions. The absence of lunula may also mean a different medical condition. However, it is vital to see a medical professional if you notice a discoloured lunula or a change in nail colour.
Perionychium
The tissue surrounding a fingernail is known as the perionychium. This includes the tissue bordering the sides of the nail and its root. The term is derived from the Greek word “onyx,” meaning nail. Interestingly, the perionychium is a common site of trauma to the fingernail. In fact, nearly 50 percent of fingernail injuries are caused by trauma to the perionychium.
When a person experiences pain around a perionychium nail, it may be an indication of another disorder. The perionygium may also be affected by verruca vulgaris, which requires multiple treatment methods. Another condition that can lead to pain is a glomus tumor, a neoplasm of smooth muscle cells that regulate the finger’s blood flow and temperature. About half of glomus tumors develop around the perionychium and cause deformities in the nail. A typical symptom of a glomus tumor is severe pain and focal cold sensitivity. A surgical procedure can remove this mass.
The perionychium contains several important structures. The nail fold and the hyponychium are the two main structures of the nail. The fold is the proximal extent of the perionychium and consists of the dorsal roof and the ventral floor. The fold is surrounded by the hyponychium, the layer of skin that surrounds the nail. It is connected to the eponychium via the fold and forms the perionychium.