Anti-Aging Skin Care
The largest organ in your body is
Skin is a
remarkable organ, the body's largest, but it is often taken for
granted. Most people are content to let it be until dryness, oiliness,
a rash or a wrinkle rouses attention. But once they understand how
it functions, many reconsider the importance of the skin and the
quality and content of the skin care products they use. Consider
1 . An adult's skin comprises between
15 and 20 percent of the total body weight.
2. Each square centimeter has 6 million
cells, 5,000 sensory points, 100 sweat glands and 15 sebaceous glands.
Skin is constantly being regenerated.
A cell is born in the lower layer of the skin called the dermis,
which is supplied with blood vessels and nerve ending. The cell
migrates upward for about two weeks until it reaches the bottom
portion of the epidermis, which is the outermost skin layer. The
epidermis doesn't have blood vessels but does have nerve endings.
The cell spends another two weeks in the epidermis, gradually flattening
out and continuing to move toward the surface. Then it dies and
is shed. Two billion to 3 billion skin cells are shed daily. The
body expends this effort to replace skin every month because the
skin constitutes the first line of defense against dehydration,
infection, injuries and temperature extremes. Skin cells can detoxify
harmful substances with many of the same enzymatic processes the
liver uses. The unbroken surface also prevents infectious organisms
from penetrating into systemic circulation. As gatekeeper, the skin
absorbs and uses nutrients applied topically. Because it cannot
completely discriminate, the skin may absorb the synthetic chemicals
often present in soaps and lotions, which at best it has no use
for and at worst can be toxic or irritating.
Most of our site visitors are committed
to natural foods and remedies, but many aren't as selective when
it comes to personal care products. These otherwise savvy shoppers
might purchase any sale shampoo, skin cleanser or lotion. But because
new skin is constantly being generated and because it plays such
an important protective role, it makes sense to choose nourishing
natural skin care products.
The epidermis is the topmost layer
of the skin. It is the first barrier between you and the outside
world. The epidermis consists of three types of cells keratinocytes,
melanocytes and langerhans cells. Keratinocytes, the cells that
make the protein keratin, are the predominant type of cells in the
epidermis. The total thickness of the epidermis is usually about
0.5 - 1 mm. At the lowermost portion of the epidermis are immature,
rapidly dividing keratinocytes. As they mature, keratinocytes lose
water, flatten out and move upward. Eventually, at the end of their
life cycle, they reach the uppermost layer of the epidermis called
stratum corneum. Stratum corneum consists mainly of dead keratinocytes,
hardened proteins (keratins) and lipids, forming a protective crust.
Dead cells from stratum corneum continuously slough off and are
replaced by new ones coming from below. The skin completely renews
itself every 3 - 5 weeks. Most mild peels work by partly removing
the stratum corneum and thus speeding up skin renewal.
Another significant group of cell
in the epidermis are melanocytes, the cells producing melanin, the
pigment responsible for skin tone and color. Finally, Langerhans
cells are essentially the front door of the immune system in the
epidermis. They prevent unwanted foreign substances from penetrating
The condition of epidermis determines
how "fresh" your skin looks and also how well your skin
absorbs and holds moisture. Wrinkles, however, are formed in lower
The epidermis consists of many layers:
- The stratum corneum, or outer layer:
This layer is made of flattened epithelial cells in multiple
layers. These layers are called keratinized layers because of
the buildup of the protein keratin in those cells. Keratin is
a strong protein that is specific to the skin, hair and nails.
This layer of skin is, for the most part, dead. It is composed
of cells that are almost pure protein.
- The translucent or transitional layer:
This is a translucent, thin layer of cells. This layer is sometimes
visible in thick skin; however, nuclei and other organelles
are not visible. The cytoplasm (the amorphous area between the
nucleus and the outer membrane of the cell) is mostly made of
- The suprabasal layers. This is three
to five layers of flattened polygonal cells that have granules
in the cytoplasm. Below them is a layer of cube-shaped cells
that also contain bundles of keratin filaments.
- The basal or cell-division layer:
This layer is just above the basement membrane and the dermis.
It is a single layer of cells that undergo cell division to
renew the upper layers of the epidermis.
Since the human epidermis is renewed every 15-60 days, proper
surface nutrition feeds the cells of the basal layer. Exfoliation
will remove dry or damaged skin of the outer layer to allow
newer cells to be visible.
The dermis is the middle layer of
the skin located between the epidermis and subcutaneous tissue.
It is the thickest of the skin layers and comprises a tight, sturdy
mesh of collagen and elastin fibers. Both collagen and elastin are
critically important skin proteins: collagen is responsible for
the structural support and elastin for the resilience of the skin.
The key type of cells in the dermis is fibroblasts, which synthesize
collagen, elastin and other structural molecules. The proper function
of fibroblasts is highly important for overall skin health.
The dermis also contains capillaries
(tiny blood vessels) and lymph nodes (depots of immune cells). The
former are important for oxygenating and nourishing the skin, and
the latter -- for protecting it from invading microorganisms.
Finally, the dermis contains sebaceous
glands, sweat glands, hair follicles as well as a relatively small
number of nerve and muscle cells. Sebaceous glands, located around
hair follicles, are of particular importance for skin health as
they produce sebum, an oily protective substance that lubricates
and waterproofs the skin and hair. When sebaceous gland produce
too little sebum, as is common in older people, the skin becomes
excessively dry and more prone to wrinkling. Conversely, overproduction
or improper composition of sebum, as is common in adolescents, often
leads to acne.
The dermis is the layer responsible
for the skin's structural integrity, elasticity and resilience.
Wrinkles arise and develop in the dermis. Therefore, an anti-wrinkle
treatment has a chance to succeed only if it can reach as deep as
the dermis. Typical collagen and elastin creams, for example, never
reach the dermis because collagen and elastin molecules are too
large to penetrate the epidermis. Hence, contrary to what some manufacturers
of such creams might imply, these creams have little effect on skin
Subcutaneous tissue is the innermost
layer of the skin located under the dermis and consisting mainly
of fat. The predominant type of cells in the subcutaneous tissue
is adipocytes or fat cells. Subcutaneous fat acts as a shock absorber
and heat insulator, protecting underlying tissues from cold and
mechanical trauma. Interestingly, most mammals lack subcutaneous
tissue because their fur serves as a shock absorber and heat insulator.
Sweat glands and minute muscles attached to hair follicles originate
in subcutaneous tissue.
The loss of subcutaneous tissue,
often occurs with age, leads to facial sag and accentuates wrinkles.
A common procedure performed by dermatologists to counteract this
process is to inject fat (collected elsewhere in the body) under
the wrinkles on the face.
Skin Care - Dermatology
is a branch of medicine dealing with the skin, its structure, functions,
and diseases (from Greek derma, "skin"). A doctor who
practices dermatology is a dermatologist.
- Contact dermatitis
- Lichen planus
- Lichen simplex chronicus
- Ring worm
- Seborrhoeic dermatitis
- Seborrheic keratosis
- Skin cancer
- Viral warts
Skin Care - Related Topics