SKINPEDIA
Your source of information about SKIN.
Skin Anatomy
The 3 Primary Layers
Skin CycleSkin Care Regimen
Skin Colour
Common Skin Conditions
Fine Lines & Wrinkles
Acne
Dehydration
Hyperpigmentation and Melasma
Rosacea
Reasons for Skin Aging
Why Does Skin Age?
Intrinsic vs. Extrinsic Aging
Genetic Aging
Key factors of
intrinsic aging
Environmental Aging
Sun exposure
Mechanical Aging
Common signs of
photo aging
Skin Anatomy
The skin is the largest organ of the human body. Defined as a
differentiated structure, the skin is made up
of specific cells and tissues with its major function being to provide
protection from the external environment.
The skin is composed of 3 primary layers
Epidermis
The epidermis is the outer layer of the skin that
protects the human body from its environment. This
is where melanocytes (cells from which melanin is
produced) are located. Comprised of four layers, the
primary purpose of the epidermis is to continually
rejuvenate the surface of the skin and protect the body.
The Basal Cell Layer - Inner layer of the epidermis
- Contains small basal cells, which are constantly being
produced, dividing and pushed up to the surface of
the skin.
- Contains melanocytes, which are responsible for skin
colour and help protect the skin from harmful UV
radiation.
- Contains sensory cells called merkel cells.
The Squamous Cell Layer - Mid epidermis layer
- “Spiny layer” – spiny projections keep cells
together.
- Maturing basal cells that travel up into this layer
are called keratinocytes.
The Stratum Granulosum & the
Stratum Lucidum - Top epidermis Layer
- Thin layers of the epidermis.
- Keratinocytes are pushed into these layers,
and begin to flatten as they grow.
- Keratinocytes fuse together to form a tough,
durable, and protective layer of cells.
The Stratum Corneum - Outermost layer
- Pushed up from beneath, new keratinocytes
continually replace dead cells as they are
shed.
Dermis
The dermis is the middle skin layer, and makes up about 90% of the skin’s
thickness. Different ethnicities have different thickness of dermis. The
main purpose of this layer is to control body temperature, as well as supply
the epidermis with nutrient saturated blood. The dermis contains many of
the skin’s cells and structures; blood vessels, lymph vessels, hair follicles,
sweat glands, eccrine glands, sebaceous glands, nerve endings, collagen and
elastin. It is comprised of two layers:
The Papillary Layer
- Delivers nutrients to the epidermis and regulates body and skin temperature.
- Contains a thin layer of collagen fibers.
The Reticular Layer
- Strengthens the skin and supports components such
as sweat glands and sebaceous glands.
- Contains elastin and thick collagen fibers that tighten the
skin and prevent sagging.
The Subcutaneous Layer
This is the inner layer of the skin and contains mostly fatty tissue, as well as blood
vessels and nerves. This layer is responsible for maintaining warmth and holding
internal organs in place. The thickness of this layer varies throughout different
areas of the body, as well as across individuals.
Skin Cycle
A skin cycle is the amount of time it takes for a
new skin cell to form and reach the surface
of the skin. As it is constantly being
exposed to and damaged by the external
environment, our skin is continually
replacing itself in order to provide optimal
protection to the body.
The time
span of a
skin cycle
varies based on
• Age
• Lifestyle
• Health
• Exposure to
UV radiation
A typical skin cycle takes about 28 days, increasing as a person ages.
Natural Skin Cell Turnover
New skin cells are produced in the base of the
epidermis and migrate towards the surface of the
epidermis as they mature, pushed upwards as skin
cells at the top of the epidermis are exfoliated away by
environmental elements. Because dead skin cells that
remain at the skin’s surface can increase the risk of
clogged pores, infections, acne breakouts, and rough
texture, regular cell exfoliation is key to healthy skin.
Skin Care Regimen and Skin Cell Turnover
Individual skin care regimens have an
impact on the efficiency of one’s skin cycle.
The rate of skin cell turnover can be increased
with topical application of specific skin care
products.
The use of products such as Retinol to
increase the rate of cell turnover, paired with
exfoliating products, such as our Clear Skin
Solution and Brightener to remove dead skin
cells from the outer layer of the skin, will increase the speed of cell turnover, resulting
in healthier, more radiant skin.
Skin Colour
It is important to understand that different
ethnic groups genetically have wide
variation of skin colour, as a result of
different levels of melanin present in the skin.
Melanin is the primary determinant of skin
tone. Produced by cells called melanocytes,
melanin production is triggered by exposure
to sunlight and ironically enough, is the
skin’s way of trying to protect itself
from the damaging effects of ultra-violet
radiation. Melanin can range in colour,
from yellow to brown to black.
Common Skin Conditions
Fine Lines & Wrinkles
Fine lines and wrinkles occur naturally as a result of
collagen and elastin deterioration in the dermis. The
location of wrinkles depends on the frequency of muscle
motions made by a person; for example, smiling and
squinting repeatedly over time causes fine lines to
become etched where the facial expression is being
made. A “groove” forms beneath the surface of the skin,
and this eventually becomes a wrinkle.
Acne
Many people struggle with excess sebum production.
When sebaceous glands overproduce oil, hair follicles
become clogged with oil and debris. Slow cell turnover
and shedding can cause an excess of dead skin
cells, and contribute to the formation of
different severities of acne.
Dehydration
Not to be confused with oil content, dehydrated skin
lacks water content. It can still have normal sebaceous
gland production, even overproduction in some cases
and can be tight, rough and flaky. Fine lines may also
be more prominent.
Hyperpigmentation and Melasma
This is a fairly common condition in which
some areas of the skin become darker
than others. Discoloration is caused by
melanin (skin pigment) deposits within the
epidermis (uppermost layer of skin), where
excess production of melanin by skin cells
called melanocytes commonly leads to
hyperpigmentation. Various conditions or
factors may alter the production of melanin
in the body. Some common causes of
hyperpigmentation are sun exposure (UVA/
UVB Rays), hormones, inflammation, and
certain medications.
Rosacea
Rosacea, caused by overstimulated nerve
endings in the dermis and epidermis, and
subsequent enlargement of capillaries, is a
chronic condition that leaves the skin
red, inflamed, and in some cases, bumpy.
Dilation of blood vessels also contributes
to the redness and in some severe cases,
sebaceous glands may be over productive,
leading to excess oil and acne formation.
3. Reasons for Skin Aging
Why Does Skin Age?
There are many different functional areas of the
skin and they all play a role in overall skin health.
Aging is a natural part of life and eventually, multiple
functional areas of the skin will show signs of aging.
Intrinsic vs. Extrinsic Aging
Intrinsic aging refers to the physiological
aging that takes place internally, omitting
external sources. The term intrinsic
is often used interchangeably with
“chronological aging”.
Extrinsic aging refers to aging that is
influenced by “external factors” such
as: ultra-violet radiation, cigarette
smoke, pollution, and other free
radical emitting sources.
Genetic Aging (Intrinsic Aging)
Eventually, a person’s skin will begin to show signs of aging, regardless of external influences.
As a result of our biological clock, these changes occur naturally within the body, varying
based on genetics factors. Many of the skin’s changes occur as a result of shifts in hormones
and messenger molecules that are produced from other glands and organs within the body.
Just like other organs in the body, the skin’s functionality begins to decrease with age.
Key factors of intrinsic aging
Collagen and elastin production
Skin cell turnover cycle
Melanin production
Oil and sweat production
When collagen and elastin production slows, these connective tissues
break, thicken and clump together. As a result, the skin begins to lose
its firmness and elasticity. Due to the skin’s inability to “snap” back into
place, this eventually leads to wrinkles and sagging. The epidermis also
becomes thinner, contributing to the sagging skin.
Melanocytes - cells that contain melanin - also decrease in quantity with
age, and remaining melanocytes become larger, leading to a more pale
and transparent complexion.
Skin cell turnover rate slows, meaning new cells don’t develop as
quickly and dead skin cells don’t exfoliate away as easily. This leads to
accumulation of dead skin cells in the epidermis, giving skin a dull or
grayish complexion.
Sebaceous glands produce less oil with age. As this oil is the skin’s natural
lubricating system, a decrease in oil production makes it difficult for the skin to
maintain its natural moisture content, making it dry and itchy.
Daily exposure to extrinsic aggressors
in the environment contributes to
accelerated aging of the skin.
4. Environmental Aging
Extrinsic factors influence skin by producing free radicals in the dermis that act
to destroy the skin’s metabolism. Free radical damage comes from a number of
sources: UV radiation, pollution, smoke, and harsh weather. Once healthy cells
are damaged, the overall composition of the skin structure is disrupted, and
over time, these free radicals result in premature aging of the skin.
Sun exposure is responsible for 95% of accelerated skin aging.
There are 3 types of ultraviolet radiation
emitted by the sun:
UVA
UVA radiation has a long wave length that penetrates the deeper
dermis layer of the skin, and is responsible for premature aging of the skin.
This radiation is present daily-rain or shine-and at the same concentration
from sunrise until sunset at all altitudes.
UVB
UVB radiation is a stronger, yet shorter wavelength that mainly affects
the outer layers of the skin. Sunburns and skin cancer are common forms
of damage to the skin caused by these rays. UVB radiation is at its most
intense from 10am to 3pm.
UVC
UVC radiation is the strongest, most dangerous form of UV light.
Fortunately, this type of radiation comes in very short wave lengths and is
absorbed into the atmosphere, unable to reach the earth’s surface.
Photo aging refers to skin damage that has been caused by the sun, and affects
skin tone, colour and texture.
The skin is able to repair itself from photo aging damage, but cells may die if the
damage is too extensive or frequent
Mechanical Aging
Facial movements and expressions, such as smiling and
frowning that are made on a daily basis also contribute
to the formation of aging lines on the skin. Moving
certain face muscles can overtime cause grooves to
form beneath the epidermis. With other biological and
environmental aging factors also affecting the skin, these
grooves eventually become wrinkles due to loss
of elasticity.
Common signs of photo aging:
• Sagging skin
• Wrinkles
• Age spots
(Hypopigmentation or Hyperpigmentation
are often the initial signs of UV skin damage)
• Tan/Sunburn
• Skin cancer