3. Introduction
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• The nails are located at the dorsal distal ends of both
fingers and toes and protect them from trauma.
• Nails create a shape of the distal and enhance capacity
for fine movements and sensation.
• This allows humans to use them as precise tools for
picking up objects.
4. The structure of the nail is divided into eleven parts and
each serves a central function.
1. Nail bed
2. Nail plate
3. Free edge
4. Hyponychium
5. Nail grooves
6. Matrix
7. Nail mantle
8. Lunula
9. Cuticle
10. Nail walls
11. Perionychium
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5. The Nail Bed
• This is the portion of skin upon which the nail plate
rests. It has very rich supply of blood and lymph
vessels to keep nail healthy.
• The function of the nail bed is to supply nourishment
and protection.
The Free Edge
• The nail plate leaves the end of the finger and forms a
projection that is called the free edge. This is attached
to the nail bed and appears as white.
• The function of the free edge is to protect the
fingertip and the hyponychium.
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6. Nail Plate
• The nail plate is composed of layers of keratinized
skin cells.
• The layers are packed very closely together with fat
but very little water content.
• The nail gradually grows over the nail bed and
becomes free edge.
• There are no blood vessels or nerves in the nail plate.
The pink color of the nail plate derives from the blood
vessels that passes beneath it.
• The main function of the nail plate is to protect the
living nail bed of the fingers and toes.
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7. The Hyponychium
• This is a part of the epidermis under the free edge of
the nail plate.
• Its function is to protect the nail bed from infection.
The Matrix
• This is the growing area of the nail and sometimes
called as the nail root. The shape and size of the
matrix determines the thickness of the nail. The
process of the keratinization takes place in the
epidermal cells of the matrix, forming the hardened
tissue of the nail plate.
• The function of the matrix is to produce new nail
cells.
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8. The Nail Grooves
• This lies along side of the edge of the nail plate.
• The function of the nail groove is to keep the nail
growing in a straight line.
The Nail Mantle
• The nail mantle is the layer of epidermis at the base of
the nail, before the cuticle. The function of the nail
mantle is to protect the matrix from physical damage.
The Lunula
• This is located at the base of the nail, lying over the
matrix. It is white in color and known as half-moon.
The nail is slightly soft in this area and can be easily
damaged.
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9. The Cuticle
• The overlapping epidermis around the base of the nail
is called the cuticle. The function of the cuticle is to
protect the matrix from infection.
The Nail Walls
• These are the folds of the skin overlapping the sides of
the nails. The function of the nail wall is to protect the
nail plate edges.
The Perionychium
• This is the collective name given to the nail walls and
the cuticle area.
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11. Composition of Nail
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• The nails are made up of hard keratin like hair.
• The protein structure contains a high proportion of
methionine, tyrosine, lysine and histidine.
• The nail is composed of three layer, a soft lower layer
called central nail, with hard keratin forming the
intermediate layer, and the outer layer called dorsal
nail.
• The nail also contains 12 to 14% water and fatty
materials called cholesterol.
15. Anonychia
• Complete absence of nail from birth.
• Anonychia is rare and appears to be associated in
several ways with other hereditary defects.
• Absence of nail may be individual, multiple or total in
some congenital conditions.
• Loss of nail plate may occurs with some inflammatory
conditions such as lichen planus and irritant dermatitis
to artificial nails or secondary to trauma.
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16. Onychomadesis
• It is the separation and
falling off of a nail from
the nail bed. Common causes
include localized infection,
minor injury to the matrix
bed, or severe systemic
illness.
• It is sometimes a side effect
of chemotherapy or x-
ray treatments for cancer.
• A new nail plate will form
once the cause of the disease
is removed.
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17. Leukonychia
• Complete whiteness of nails or spots
on the nail frequently occurs and is
not necessarily termed as disease.
• One suggestions is that this is due to
the injury to nail with simultaneous
production of air bubbles.
• Alternative suggestions is that this
may be due
keratohyalin
to the presence of
granules or enlarged
acidophilic cells.
• The diffusion of light by these
granules makes the cells appear white
instead of pink.
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18. Onycholysis
• The separation of nail from its bed is fairly common
It may result from external damage both traumatic and
self induced that is overaggressive cleaning, fungal and
yeast infection, acute or chronic dermatitis or drug
eruptions.
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19. Koilonychia
• This is also called spoon nails, as the nails are
depressed in centre and raised at the edges like a
spoon.
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20. Brittleness
• Brittleness of nails may be caused
by congenital defects, systemic
disorder or due to some other
factors.
• The brittle nails may split easily.
Systemic disorder which can make
nail brittle are anaemia,
avitaminosis, gout, hyper and hypo
thyroidism.
• Sometimes continous use of nail
vernishes or vernish remover
without supplementing in between
with nail creams, may also cause
brittleness.
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21. Onychorrhexis
• Longitudinal striations are common in healthy nails
and become more prominent with aging, and in lichen
planus, psoriasis and some other clinical and
occupational conditions.
• More prominent longitudinal ridging is seen in median
nail dystrophy which is attributed to habit tics (self
induced behavior).
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22. Pitting
• Pitting of the nails is found most commonly in
psoriasis.
• Pits represents punctuated or depressed sites in the nail
plate secondary to irregular matrix production. They
can vary in size, shape, depth and number.
• They are most common manifestations of nail
psoriasis but can also be seen in chronic dermatitis,
fungal infections, reiters syndrome, and lichen planus.
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23. Paronychia
• Paronychia is defined as inflammation
of proximal or lateral nail folds or a
combination of the two.
• Paronychia occurs after loss of the cuticle or either by
trauma or aggressive cuticle trimming or cuticle
pulling.
• It can be acute or chronic.
• Acute paronychia is caused by introduction of an
infectious agent into the nail folds, usually through
trauma , cuticle pulling or exposure to an irritant agent.
• Chronic paronychia occurs over time due to continuous
exposure to an irritant behavior, constant exposure to
water from hand washing, or a specific contactant such
as food items or chemical irritant.
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24. Discoloration
• Nails may discolored for a variety of reasons.
• External causes include hair and other chemical dyes,
smoking and chemical compounds such as mercury
salt, dithranol and picric acid.
• The use of artificial nails and either acrylic or
preformed plates can cause discoloration.
• Abnormal or very slow growth of the nails may can
also produced color changes.
• In the yellow nail syndrome the nail almost cease to
grow and several months later become yellow or
greenish.
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25. References
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1. B. M. Mithal, R. N. Saha “ A handbook of cosmetis”
Vallabh Prakashan, First edition p.no 178-181.
2. Dr. Martin M. Reiger “Harrys Cosmetology”
Chemical publishing Co. Inc. New York, 8th p.no:71-
79.
3. www.wikipedia.com
