Melanin
The human
skin color is primarily due to melanin, it ranges from skin almost black in
appearance to white with a pinkish tinge due to blood vessels underneath. Variations
in skin hue are mainly of genetic origin and are associated with sunlight, but
the evolutionary causes are not completely certain. The leading explanation is
they are adaptations to sunlight intensities which produce vitamin D deficiency
or ultra violet light damage to folic acid. Other hypothesis includes
protection from ambient temperature, infections in the food and sexual
selection. According to scientific studies, natural human skin color diversity
is highest in black or sub-Saharan African populations.
skin color is primarily due to melanin, it ranges from skin almost black in
appearance to white with a pinkish tinge due to blood vessels underneath. Variations
in skin hue are mainly of genetic origin and are associated with sunlight, but
the evolutionary causes are not completely certain. The leading explanation is
they are adaptations to sunlight intensities which produce vitamin D deficiency
or ultra violet light damage to folic acid. Other hypothesis includes
protection from ambient temperature, infections in the food and sexual
selection. According to scientific studies, natural human skin color diversity
is highest in black or sub-Saharan African populations.
In human,
melanin is the primary determinant of skin color. It is also found hair, the
pigmented tissue underlying the iris or the eye and the stria vascularis of the
inner ear. In the brain, tissues with melanin include the medulla and zona
rticularis of the adrenal glands and pigment bearing neurons within areas of
the brain stem, such as the locus coeruleus and the substantia nigra
melanin is the primary determinant of skin color. It is also found hair, the
pigmented tissue underlying the iris or the eye and the stria vascularis of the
inner ear. In the brain, tissues with melanin include the medulla and zona
rticularis of the adrenal glands and pigment bearing neurons within areas of
the brain stem, such as the locus coeruleus and the substantia nigra
The
melanin in the skin is produced by melanocytes, which are found in the basal
layer of the epidermis. Although human beings generally possess a similar
concentration of melanoctytes their skin, the melanocytes in some individuals
and ethic groups more frequently or less frequently express the melanin-
producing genes, thereby conferring a greater or lesser concentration of skin
melanin. Some individual animals and humans have very little or no melanin in their
bodies a condition known as albinism
melanin in the skin is produced by melanocytes, which are found in the basal
layer of the epidermis. Although human beings generally possess a similar
concentration of melanoctytes their skin, the melanocytes in some individuals
and ethic groups more frequently or less frequently express the melanin-
producing genes, thereby conferring a greater or lesser concentration of skin
melanin. Some individual animals and humans have very little or no melanin in their
bodies a condition known as albinism
Because
melanin is an aggregate of smaller compound molecules, there are number of different
types of melanin with differing proportions and bonding, pattern of these
component molecules. Both pheomelanin and hair, but eumelanin is the most
abundant melanin in humans as well as the form most likely to be deficient in
albinism.
melanin is an aggregate of smaller compound molecules, there are number of different
types of melanin with differing proportions and bonding, pattern of these
component molecules. Both pheomelanin and hair, but eumelanin is the most
abundant melanin in humans as well as the form most likely to be deficient in
albinism.
Keratin
Keratin
is one of a family or fibrous structural protein. Keratin is the protein that
protects epithelial cells from damage or stress that has potential to kill the
cell. It is the key structural materials making up the outer layer of human
skin. It is the key structural component of hair and nails, and it provides the
necessary strength and toughness for masticating organs, such as the tongue and
the hard palate. Keratin monomers assemble into bundles to form intermediate
filaments, which are tough and form strong unmineralized tissue found in
reptiles, birds, amphibians and mammals. The only other biological matter know
to approximate the toughness of keratinized tissue is chitin.
is one of a family or fibrous structural protein. Keratin is the protein that
protects epithelial cells from damage or stress that has potential to kill the
cell. It is the key structural materials making up the outer layer of human
skin. It is the key structural component of hair and nails, and it provides the
necessary strength and toughness for masticating organs, such as the tongue and
the hard palate. Keratin monomers assemble into bundles to form intermediate
filaments, which are tough and form strong unmineralized tissue found in
reptiles, birds, amphibians and mammals. The only other biological matter know
to approximate the toughness of keratinized tissue is chitin.
Keratinocytes
in the cornified layer of the epidermis, these are proteins which have
undergone keratinization. In addition, keratin filament are present in epithelial cells in general
for example, mouse thymic epithelial cells know to react with antibodies for
keratin 5, keratin 8 and keratin 4. These antibodies are used as fluorescent
makers to distinguish subset of TECS in genetic studies of the thymus.
in the cornified layer of the epidermis, these are proteins which have
undergone keratinization. In addition, keratin filament are present in epithelial cells in general
for example, mouse thymic epithelial cells know to react with antibodies for
keratin 5, keratin 8 and keratin 4. These antibodies are used as fluorescent
makers to distinguish subset of TECS in genetic studies of the thymus.
Keratin
(also described as cytokeratined are polymers of types III and type IV
intermediate filaments, which have only been found in the genomes of chordate
(vertebrate, amphioxus, urochordate) nematodes and many other non-chordate
animals seem to only have type VI intermediate filaments, iamins, which here a
long rod domain (Vs a short rod domain
for the keratins
(also described as cytokeratined are polymers of types III and type IV
intermediate filaments, which have only been found in the genomes of chordate
(vertebrate, amphioxus, urochordate) nematodes and many other non-chordate
animals seem to only have type VI intermediate filaments, iamins, which here a
long rod domain (Vs a short rod domain
for the keratins
Blood
There are
four (4) pigments in the normal skin that affect its color. Melanin oxygenated
hemoglobin reduced hemoglobin and various carotene of this melanin is the most
powerful. The cells that produce it are the same in all races but there is wide
variation in the amount produced and wide variation in the color, which ranges
from black to light tan every adult, has about 60.000 melanin producing cells
in each square inch of skin. Melanin cells also affect eye color when the cells
are deep in the eye the is brown. An albino a person with no melanin has eyes
that appear pink because the stronger pigment tat ordinarily masks the blood
vessels is lacking.
four (4) pigments in the normal skin that affect its color. Melanin oxygenated
hemoglobin reduced hemoglobin and various carotene of this melanin is the most
powerful. The cells that produce it are the same in all races but there is wide
variation in the amount produced and wide variation in the color, which ranges
from black to light tan every adult, has about 60.000 melanin producing cells
in each square inch of skin. Melanin cells also affect eye color when the cells
are deep in the eye the is brown. An albino a person with no melanin has eyes
that appear pink because the stronger pigment tat ordinarily masks the blood
vessels is lacking.
Hemoglobin
The
pigment that gives blood its color called hemoglobin has the next greatest
effect on skin color. When it is combined with oxygen, a bright red is the
result and this in tore produce the rosy complexion associated with good health
in light skinned people. When such people suffer from reduced hemoglobin
because of anemia, they appear to be excessively pale. A concentration of
reduced hemoglobin gives the skin a bluish appearance because hemoglobin has a
weaker coloring effect that the melanin that determines basic skin color, these
variations are more visible in lighter-skinned individuals
pigment that gives blood its color called hemoglobin has the next greatest
effect on skin color. When it is combined with oxygen, a bright red is the
result and this in tore produce the rosy complexion associated with good health
in light skinned people. When such people suffer from reduced hemoglobin
because of anemia, they appear to be excessively pale. A concentration of
reduced hemoglobin gives the skin a bluish appearance because hemoglobin has a
weaker coloring effect that the melanin that determines basic skin color, these
variations are more visible in lighter-skinned individuals
Carotenes
The
weakest pigment in the skin is the carotenes. These produce a yellowish tone
that is increases by eating excessive amounts of carrots and orange. In people
with black or brown skin, excess carotene is usually
weakest pigment in the skin is the carotenes. These produce a yellowish tone
that is increases by eating excessive amounts of carrots and orange. In people
with black or brown skin, excess carotene is usually
Collagen
Both
collagen and melanin play a protective role in healthy skin. Melanin absorbs
harmful ultra violet light and protects the skin from photo damage. Skin
collagen molecules, thus creating the skin organ. It provides protection
against disease and injury. The thicker the skin and the more melanin, the
better the protective barriers against the effects of aging
collagen and melanin play a protective role in healthy skin. Melanin absorbs
harmful ultra violet light and protects the skin from photo damage. Skin
collagen molecules, thus creating the skin organ. It provides protection
against disease and injury. The thicker the skin and the more melanin, the
better the protective barriers against the effects of aging
Melanin
Melanin
is a class of biological pigments as photo-protection of skin. Pigment cells
named melanocytes produce melanin in outer skin layer. All melanocytes produce
melanin, but cells in darker skinned people produce more per cell. The two
melanin produced by human skin include black- brown, eumelanin and yellow –red
pheomelanin. Each melanin has seprate biological properties. Also women produce
3 to 4 percent less melanin in their skin than men.
is a class of biological pigments as photo-protection of skin. Pigment cells
named melanocytes produce melanin in outer skin layer. All melanocytes produce
melanin, but cells in darker skinned people produce more per cell. The two
melanin produced by human skin include black- brown, eumelanin and yellow –red
pheomelanin. Each melanin has seprate biological properties. Also women produce
3 to 4 percent less melanin in their skin than men.
Melanin Functions
Before
global migration most humans with the darken skin lived closest to the equator.
Melanin absorbs ultra violet light. Thus
protecting humans from harmful radiation damage skin cells and promote melanoma
cancere of the skin European Americans have a lot times higher risk of melanoma
than African American even though melanin is protective complete shielding
would be harmful because short wave uv radiation needs vitamins D is
synthesized in the skin.
global migration most humans with the darken skin lived closest to the equator.
Melanin absorbs ultra violet light. Thus
protecting humans from harmful radiation damage skin cells and promote melanoma
cancere of the skin European Americans have a lot times higher risk of melanoma
than African American even though melanin is protective complete shielding
would be harmful because short wave uv radiation needs vitamins D is
synthesized in the skin.