CHAPTER 3 PHYSIOLOGY AND HISTOLOGY

WHY IS IT IMPORTANT TO LEARN AND UNDERSTAND PHYSIOLOGY AND HISTOLOGY OF THE SKIN

• there is so much to study about the bodys largest organ and how to maintain its optimum health

• The complexity of skin is astonishing (the layers, components, and functions all work with other body systems to protect and regulate the skin and other parts of the body)

• Includes learning about the aging process as well as interpreting the effects of UV damage, hormonal influences, and nutrition on skin health

HISTOLOGY

• the study of the structure and composition of tissue

• MICROSCOPIC ANATOMY

PHYSIOLOGY

• the study of the functions and activities performed by the body structures (including physical and chemical processes)

ESTHETICIAN

• Estheticians who specialize in the health and beauty of the skin are sometimes referred to as technicians, skin therapists, or specialists

FUN SKIN FACTS

• thinnest skin is on your eyelids and under your eyes

• Skin is about 15% of your body weight

• Skin has 3 layers (epidermis, dermis, and subcutaneous)

• Every inch of your skin has a unique stretchiness and strength

• Everyone has the same number of melanocytes

• the skin is about 50-70% water

INTEGUMENTARY SYSTEM

• skin

• Largest organ in the body

• It is a strong barrier designed to protect us from the outside elements

• Skin layers, nerves, cellular functions, hair follicles, and glands all work together harmoniously to regulate and protect the body

• Hormones, growth factors, and other biochemical control the skins intricate functions

• Appendages of the skin are hair, nails, sweat glands, and oil glands

• Healthy skin is slightly moist, soft, smooth, and somewhat acidic

• Waterproof, an insulator (protects from extreme heat, cold, and damaging UV rays), a barrier (protects from harmful chemicals and bacteria), sensory storehouse, producing vitamin d

• 6 primary skin functions (sensation, protection, heat regulation, excretion, secretion, and absorption)

SENSATION

• nerve fibers in the skin sense when we are touched

• Touch is one of the first senses to develop

• Depending on the type of stimulation, sensations felt on the skin cause us to feel, react, or move

• Fingertips have the most sensory nerve fibers

• Different nerve sensors help us detect different sensations and perceive changes in our environment (heat, cold, touch, pain, and pressure)

• Nerve sensors send messages to the brain and motor nerves send messages back to relay to the body how to respond

PROTECTION

• The skin is a thin, yet strong, protective barrier to outside elements (it has many defense mechanisms to protect the body)

• Sebum (oil) on the epidermis gives protection from external factors such as invasion of bacteria

• ACID MANTLE : the protective barrier made of sebum, lipids, sweat, and water ; has an average Ph of 5.5 ; part of the skins natural barrier function

• HYDROLIPIDIC : hydrolipidic film is an oil-water balance that protects the skins surface ; protects the skin from drying out and from exposure to external factors that could damage it ; provides and oil-water balance on the skin’s surface

• MELANOCYTES : cells that produce pigment and protect our bodies from harmful ionizing UV rays ; melanocytes produce pigment granules called melansomes (produce melanin)

• MELANIN : travels from the deeper basal cell layer of the stratum germinativum to the surface through fingerlike projections called dendrites, acting as an umbrella to shield the skin from the negative effects of the sun and indoor tanning

• BARRIER FUNCTION : protective barrier of the epidermis ; the corneal and intercellular matrix protect the surface from irritation and dehydration ; skins mechanism that protects us from irritation and intercellular TEWL

• TEWL : trans epidermal water loss ; water loss caused by evaporation on the skins surface

• damage to the barrier layer is the cause of many skin problems, including sensitivities, aging, and dehydration

• LIPIDS : substances that contribute to the barrier function of the epidermis ; protective oils and are part of the intrercellular matrix

• INTERCELLULAR MATRIX : lipid substances between corneum cells that protect the cells from water loss and irritation

• EPIDERMAL GROWTH FACTOR : EGF ; a hormone that stimulates cells to reproduce and heal

• FIBROBLASTS : cells that stimulate cells, collagen, and amino acids that form proteins

• The skin has the ability to heal itself (through hyper-production of cells and blood clotting, injured skin can restore itself to it normal thickness)

HEAT REGULATION

• the bodys internal temperature is 98.6 degrees Fahrenheit (37 degrees Celsius)

• The skin automatically adjusts to warm or cool the body based on outside temperatures

• The body maintains thermoregulation through evaporation, perspiration, radiation, and insulation

• Sweat glands release heat from the body through perspiration to prevent overheating and cool further through evaporation on the skins surface

• Blood flow and blood vessel dilation also assist in cooling the body

• Protect ourselves from the cold by constriction of the blood vessels and decreased blood flow (additionally, body’s fat layer help to insulate and warm the body)

• Hair follicles also help regulate body temp and protect from heat loss (arrector pili muscles contract and cause goosebumps)

• FOLLICLES : hair follicles / sebaceous follicles are tube-like openings in the epidermis (tubelike depressions with oil glands attached to them, some with hair, some without)

• ARRECTOR PILI MUSCLE : small, involuntary muscles in the base of the hair follicle that cause goose flesh when the appendage contracts (this reaction is thought to warm the skin by the air pockets that are created under the hairs that stand up when the muscle contracts)

• PORES : tube-like opening for sweat glands on the epidermis

• Shivering is an automatic response to cold and a way to warm the body

EXCRETION

• SUDORIFEROUS GLANDS : sweat glands ; excrete perspiration, regulate body temperature, and detoxify the body by excreting excess salt and unwanted chemicals

SECRETION

• SEBUM : oil that provides protection for the epidermis from external factors and lubricates both the skin and hair

• SEBACEOUS GLANDS : oil glands ; protect the surface of the skin ; appendages connected to follicles that produce sebum

• these oils keep the skin soft and protected from outside elements

• sebum coating the surface of the skin slows down the evaporation of water (TEWL) and helps maintain appropriate water levels in the cells

ABSORPTION

• absorption of chemicals, hormones, moisture, and oxygen is necessary for our skins health (vitamin d is synthesized and produced in the skin upon UV exposure)

• the skin selectively absorbs topical products, serums, and creams through the hair follicles, cells, and sebaceous glands

• some ingredients with a smaller molecular size can penetrate the skin (penetration ability is determined by molecule size and other characteristics of the product) lipid-soluble products penetrate better

• penetration routes are through follicule walls, sebaceous glands, intercellular, or transcellular

• INTERCELLULAR : “between” the cells

• TRANSCELLULAR : “across” or through the cells

• small molecules with permeable cell walls can penetrate the cells and large molecules with non permeable cell walls can be temporarily absorbed by the glands and can travel through the intercellular spaces

• absorbtion of topical products helps keep the skin moisterized, nourished, and protected

PROTEINS

• the basic material and building block for our bodys tissues

AMINO ACIDS

• form peptides (peptides form proteins)

SUBCUTANEOUS TISSUE

• subcutaneous adipose (fat) tissue located beneath the dermis ; a protective cushion and energy storage for the body

• deepest layer of the skin

• This layer is 80% fat

• Also known as the hypodermic or superficial fascia

• Composed of loose connective tissue or subcutis tissue , also known as adipose tissue

• SUBCUTIS TISSUE : also known as adipose tissue ; fatty tissue found below the dermis that gives smoothness and contour to the body, contains fat for use as energy, and also acts as a protective cushion for the outer skin

• Contains vessels, nerves, fibers, adipose cells, and fibroblasts

• This layer decreases and thins with age

• A thicker subcutaneous layer may have underlying hormonal disorder (deserves further exploration when you perform your skin consultation)

DERMIS

• middle layer of the skin

• Support layer of connective tissue, collagen, and elastin below the epidermis

• Also known as the derma, corium, cutis, or true skin

• About 25 times thicker than the epidermis

• Supplies the skin with oxygen and nutrients through a network of blood vessels and lymphatic channels

• Primarily comprised of connective tissues made of collagen protein and elastin fibers

• blood vessels, lymph vessels, capillaries, follicles, sebaceous glands, sudoriferous glands, sensory nerves, additional receptors, and arrector pili muscles are all in the dermis

• LYMPH VESSELS : supply nourishment within the skin and remove waste products, bacteria, and excess fluid; located in the dermis

• fibroblasts (cell stimulators), lymphocytes (infection fighters), langerhans cells (gaurd cells), mast cells (involved in allergic reactions), and leukocytes (white blood cells to gight infections) are all found in the dermis

• EXTRACELLULAR MATRIX : compsoed of collagen, other proteins, and GAGs ; these intercellular substances comprise fluid with other compnents to maintain balance, provide dermal support, amd assist cell metabolism, growth, and migration

• Consists of two layers (the reticular layer below and the papillary layer above)

RETICULAR LAYER

• bottom dermis layer

• the denser and deeper layer of the dermis

• Comprised mainly of collagen and elastin

• Deeper layer of the dermis that supplies the skin with oxygen and nutrients ; contains fat cells, blood vessels, sudoriferous (sweat) glands, hair follicles, lymph vessels, arrector pili muscles, sebaceous (oil) glands, and nerve endings

• Damage to these elastin fibers as they break down is the primary cause of sagging, wrinkles, and intrinsic aging—loss of elasticity in the skin

• Collagen and elastin are broken down by UV damage, smoking, and environmental influences such as air pollution

PAPILLARY LAYER

• Top layer of the dermis (next to the epidermis)

• Connects the dermis to the epidermis with dermal papillae

• 10-20% of the dermis

• DERMAL PAPILLAE : membranes of ridges and grooves that attach to the epidermis ; contains nerve endings and supplies nourishment through capillaries to skin and follicles

• HAIR PAPILLAE : small, cone shaped structures at the bottom of the hair follicles

DERMAL/EPIDERMAL JUNCTION (DEJ)

• connects the dermis to the epidermis

• consists of layers of a connective collagen tissue with many small pockets and holes

• collagen fibrils from the dermis are embedded ito these layers to provide strength and adhesion

• keratin filaments on the epidermis side also ensure strength and adhesion to the junction

• some states define an estheticians scope of prectice as “not beyond the DEJ” meanign the esthetician cannot treat the skin beyond the epidermis

COLLAGEN

• a protein substance of complex fibers that gives skin its strength and is necessary for wound healing

• Fibrous, connective tissue made from protein

• Gives skin its firmness

• Found in the reticular layer of the dermis

• Topically, a large, long chain molecular protein that lies on the top of the skin and binds water ; derived from the placentas of cows or other sources

• Collagen makes up 70% of the dermis (fibroblast cells produce proteins and aid in the production of collagen and elastin)

ELASTIN

• protein fiber found in the dermis

• Gives skin its elasticity and firmness

• Makes up a small percent of the dermis (1/15 the amount of elastin compared to collagen in the dermis)

• stretch marks are caused by damaged elastin fibers

GLYCOSAMINOGLYCANS

• a water-binding substance such as a polysaccharide (protein and complex sugar) found between the fibers of the dermis

• GAGs

• polysaccharides (proetin and sugar complexes)

• work to maintain and support collagen and elastin in the the cellular spaces, keeping protein fibers in balance ; also help elastin and collagen retain moisture

• interact with copper peptides for cellular repair

• healthy fluid intake is essential to keep GAGs functioning properly

HYALURONIC ACID

• type of GAG (glycosaminoglycan)

• hydrating fluids found in the skin

• hydrophilic agent with water binding properties

EPIDERMIS

• outermost layer

• Thinnest layer

• The epithelial tissue that covers our body

• A thin protective layer with many cells, mechanisms, and nerve endings

• Made of 5 layers called strata (stratum germinativum, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum)

STRATUM GERMINATIVUM

• Also known as the basal cell layer (bottom layer)

• “Germination or growth layer”

• Active layer of the epidermis above the papillary layer of the dermis ; cell mitosis takes place here to produce new epidermal skin cells (responsible for growth)

• compsoed of a single layer of basal cells laying on a “basement membrane”

• in this active layer stem cells undergo continuous cell division (mitosis) to replenish the skin cells that are regularly shed from the surface

• cells in this layer produce necessary lipids that form cell embranes and hold cells together

• MERKEL CELLS : sensory cells ; touch receptors located in the basal layer

• contains melanocytes (cells that produce pigment granules in the basal layer)

• 5-10% of the basal cells are melanocytes

STRATUM SPINOSUM

• also known as the spiny layer

• Above the stratum germinativum

• Layer of the epidermis bone the stratum germinativum layer containing desmosomes, the intercellular connections made of proteins

• Largest layer of the epidermis

• Cells continue to divide and change shape, and enzymes create lipids and proteins in this layer

• Cell appendages (that resemble prickly spines) become desmosomes, the intercellular structures that assist in strengthening and holding cells together

• DESMOSOMES : the structures that assist in holding cells together ; intercellular connections made of proteins ; keratin filaments ; protein bonds that create the junctions bewteen the cells ; stengthen the epidermis and assist in intercellular communictaion

• LANGERHANS IMMUNE CELLS : gaured cells of the immune system that sense unrecognized foreign invader, such as bacteria, and then process these antigens for removal through the lymph system

• LAMELLAR GRANULES : epidermal cells composed of keratin, lipids, and other proteins ; cells that contain lipids to maintain the barrier function

STRATUM GRANULOSUM

• granular layer

• Layer of the epidermis composed of cells filled with keratin that resemble granules ; replace cells and shed from the stratum corneum

• Production of keratin and intercellular lipids take place here

• Enzymes dissolve the structures (desmosomes) that hold cells together ; as these cells become keratinized, they move to the surface and replace the cells shed from the stratum corneum

• Natural moisturizing substances (triglycerides, ceramides, waxes, fatty acids, and other intercellular lipids) are made here and are excreted fro cells to form components of the skins waterproofing barrier function of the top layer ; these water soluble compounds are referred to as natural moisturizing factors (NMFs) and hydrate the lipid layer surrounding cells, absorb water, and prevent water loss

STRATUM LUCIDUM

• clear, transparent layer of the epidermis under the stratum corneum

• thickest on the palms of the hands and soles of the feet (composed of epidermal ridges that provide a better grip while walking and using our hands)

• Thin, clear layer of dead skin cells under the stratum corneum

• Made of small cells that let light pass through

• The keratinocytes in this layer contain clear keratin

• Cells here release lipids, forming bilayers of oil and water

• Forms our unique fingerprints and footprints

STRATUM CORNEUM

• outermost layer of the epidermis, composed of corneocytes

• CORNEOCYTES : hardened, waterproof, protective keritinocytes ; stratum corneum cell ; these “dead” protein cells are dried out and lack nuclei

• also known as the horny layer (because of the sclae-like cells ; corneocytes)

• very thin, waterproof and permeable, regenerates itself, detoxifies the body,a dn responds to stimuli

MELANIN

• tiny grains of pigment (coloring matter) that are produced by melanocytes and deposited into cells in the basal layer of the epidermis and in the papillary layers of the dermis ; a protein that determines hair, eye, and skin color

• produced as a defense emchanism to protect us from the sun ; pigment that protects us from the sun

• Internal and external factors affect melanin activation

• Difference in genetic skin color are due to the amount of melanin activated in the skin and the way it is distributed

• Production is stimulated by exposure to sunlight ad protects cells below by absorbing and blocking UV radiation

• Body produces 2 types of melanin (pheomelanin and eumelanin)

• PHEOMELANIN : a type of melanin that is red and yellow in color ; people with light colored skin produce mostly pheomelanin

• EUMELANIN : a type of melanin that is dark brown to black in color ; people with dark colored skin produce mostly eumelanin

MELANOCYTES

• cells that produce skin pigment granules in the basal layer

MELANOSOMES

• pigment carrying grnaules that produce melanin, a complex protein

TYROSINASE

• the enzyme that stimulates melanocytes and thus produces melanin

KERATINOCYTES

• epidermal cells composed of keratin, lipids, and other proteins

• comprise 95% of the epidermis

• many different functions and go through chnages as they move up the layers of the epidermis

• protect the epidermis

KERATIN

• fibrous protein of cells that is also the principla componenent of skin , hair, and nails

• provides resiliency and protection

• found in all layers of the epidermis

• forms continuous sheets (fingernails) or long, endless fibers (hairs)

STEM CELLS

• mother cells

• divide in the basal layer (stratum germinativum) and form new daughter cells

• mother cells divide into 2 daughter cells (some mother na daughter cells remain undifferentiated and keep dividing for constant self renewal over a lifetime)

• daughter cells that cant divide anymre have the capability to program themselves to end up as one specific cell (this is known as terinal differentiation)

A-KERATIN

• alpha keratin

• soft keratin

• higher moisture and fat content

B-KERATIN

• beta keratin

• Hard keratin

• Lower moisture and fat content

• hair and nails

• tough eleastic material

HAIR AS AN APPENDAGE

• 90% b keratin

• heavier concentrations on the head, underarms, genitals, arms, and legs

• due to hormonal influences there are different growth patterns for men and women

• genetics influence the distribution of each persons hair, along wit its thickness, quality, color, rate of growth, and whether it is curly or straight

• roughly 0.5 inches of growth per month (6 inches a year)

• contains melanin

NAILS

• an appendage of the skin

• A hard translucent plate that protects fingers and toes

• Composed of hard keratin

• ONYX IS THE TECHNICAL TERM FOR NAIL

• B keratin

• no nerves or blood vessels

• fingernails grow faster than toenails

• fingernails grow faster in the summer than in the winter

• 1/10 inch to 1/8 inch growth a month (4-6 months to fully grow out)

CYANOSIS

• a person has a purple or bluish tone under their fingernails

NERVES

• cordlike bundles of fiber made up of neurons through which sensory stimuli and motor impulses pass between the brain or other parts of the central nervous system and the eyes, glands, muscles, and other parts of the body

• 2 types (motor and sensory)

MOTOR NERVES

• efferent nerves

• Nerve fibers convey impulses from the brain or spinal cord to the muscles or glands

• Stimulate muscles (arrector pili)

• Secretory nerves are motor nerves attached to sweat and oil glands (regulate excretion from the sweat glands and control sebum output to the skin’s surface)

SENSORY NERVES

• afferent nerves

• Send messages to the central nervous system and brain to react to heat, cold, pain, pressure, and touch

SEBACEOUS GLANDS

• oil glands

• Connected to the hair follicles and produce oil, which protects the surface of the skin

• Glandular sacs open into the follicles through ducts (if the ducts become clogged, open or closed comedones are formed)

• Oily secretions lubricate the skin and hair

• Sebaceous glands are larger on the face and scalp then the rest of the body

SUDORIFEROUS GLANDS

• sweat glands

• Help to regulate body temperature and eliminate minute amounts of waste products by excreting sweat

• They have a coiled base and duct openings at the surface (pores)

• Fluids and minerals are eliminated daily through these pores ; normally 1-2 pints of fluid containing trace amounts of minerals (potassium, sodium, and magnesium) are eliminated daily

• Excess fluid loss can result in dehydration in the body

• 2 types of sweat glands (Apocrine and eccrine)

APOCRINE GLANDS

• Coiled structures attached to hair follicle in the underarm and genital areas that secrete sweat

• Apocrine secretions are released through the oil glands

• Function is sensitive to adrenaline (can occur during times of anxiety, stress, fear, arousal, and pain)

• Odors associated with these glands are due to the interactions of the secretions and bacteria on the surface of the skin

• Produce chemicals known as pheromones (hormones that trigger biological reactions or communicate signals to others) thought to attract others through scent production (commonly called body chemistry)

ECCRINE GLANDS

• sweat glands found all over the body with openings on the skins surface through pores

• Not attached to hair follicles

• Primarily on the forehead, palms of the hands, and soles of the feet

• Have a duct and pore through which secretions are released on the skins surface (does not smell)

• More active when the body is subjected to physical activity and high temperatures

SKIN HEALTH FACTORS

• in order to survice cells need : nourishment, proection, and the ability to function properly through repiration, circulation, elimination of wastes, and continual replacemtn or proliferation

IMMUNE SYSTEM

• complex defense mechanism that protects the body from foreign substances (activated with antigens are identified)

• ANTIGENS : foreign invaders

• ANTIBODIES : molecules formed to fight and neutralize bacteria, viruses, and antigens

• infections and allergic reactions speed up cell growth and migration rates for faster healing

LANGERHAN CELLS

• dendritic in form

• present predominantly in the stratum spinosum (also in other layers of the skin)

• They work to absorb, process, and carry antigens to the nearest lymph node for further immune system action

LEUKOCYTES

• white blood cells

• Have enzymes to digest and kill bacteria and parasites

• Also respond to allergies

TCELL

• type of lymphocyte

• Identify molecules that have foreign peptides and also help regulate immune response

• Attacks virus-infected cells, foreign cells, and cancer cells

SKIN NOURISHMENT

• Blood and lymph nourish the skin

• Networks of arteries and lymphatics send essential materials for growth and repair throughout the body

• Water, vitamins, minerals, and other nutrients are important for skin health

• BLOOD : supplies nutrient and oxygen to the skin

• NUTRIENTS : molecules from food such as protein, carbohydrates, and fats

• TOPICAL PRODUCTS : with small molecules can nourish the epidermis

• LYMPH : the clear fluid of the body that resembles blood plasma but contains only colorless corpuscles, bathes the skin cells, removes toxins and cellular waste, and has immune functions that help protect the skin and body agaisnt disease

CELL PROTECTION

• the health of the skin depends on the cellular membrane and the water-holding capacity of the stratum corneum

• LIPIDS : intercellular lipids and proteins surround cells and provide protection, hydration, and nourishment to the cells

• CERAMIDES : glycolipid materials that are a natural part of skins intercellular matrix and barrier function ; group of waxy lipid molecules such as glycolipids that are important to barrier function and water holding capacity (50% of lipids in the stratum corneum are ceramides)

• CELL RECOVERY : depends on water to function properly (essential to keep skin hydrated and drink water to keep cells healthy)

CELL REPLACEMENT

• cells of organs (skin, heart, liver, and kidneys) are replaced every 6-9 months

• Elastin and collagen are not easily replaced by the body (skin doesn’t regain its once pliable shape after being stretched or damaged by UV radiation and environmental pollution)

• Research shows that certain skin care ingredients / treatments such as, vitamin a, AHAs, alpha lipoeic acid, and other growth factors stimulate skin cell turnover and reduce visible signs of aging

• Reglar cell turnover is necessary to keep skin healthy

SUN DAMAGE

• The sun and UV electromagnetic radiation have the greatest impact on skin aging

• 80-85% of our aging is caused by sun exposure

• According to the U.S department of health and human services, ultraviolet radiation (UVR) is a proven carcinogen

• UV exposure alters DNA and can cause skin cancer

• Frequent UV exposure accelerates the weakening of collagen and elastin fibers

• UV reaches skin in 3 forms (UVA, UVB, UVC)

UVA RADIATION

• known as aging rays

• Contributes up to 95% of the suns UVR that reaches earths surface the longer wavelengths of UVA (320-400 nanometers) penetrate deeper into the skin and cause genetic damage and cell death

• Weakens the skins collagen and elastin fibers, causing wrinkling and sagging in the tissues

• Present all year ; more prevalent that UVB ; can penetrate glass and clouds

UVB RADIATION

• known as burning rays

• Causes burning of the skin as well as tanning, aging, and cancer

• Wavelengths are shorter than UVA wavelengths (290-320 nanometers) but are stronger and more damaging to the skin and can damage the eyes

• Contributes to the body’s synthesis of vitamin d and other important minerals

UVC RADIATION

• more energy that UVA or UVB

• Reacts with the ozone high in our atmosphere and from human made sources such as welding torches, and UV sanitizing bulbs that kills bacteria and other germs

HEV LIGHT

• high energy visible light

FREE RADICAL DAMAGE

• free radicals have an unbalanced electrical charge (molecules are in homeostasis or balance when electrons are paired)

• molecules may lose electrons due to UV ray damage, the environment, poor nutrition, unhealthy lifestyle, or injuries

• Inflammation creates free radicals

• Free radicals are reactive oxidants searching the body for other electrons that will allow them to become stable, neutral molecules again

• Free radicals are unstable and a chain reaction of cellular destruction begins as they steal electrons from other molecules (such as proteins, lipids, and DNA) to try and put themselves back in a state of homeostasis (balance)

• Free radicals are superoxidizers that not only cause an oxidation reaction but produce new free radicals in the process (cellular destruction chain)

• Antioxidants have an extra electrons and are vital to neutralize this chain reaction by donating their extra electrons to stabilize free radicals

• Proteins, enzymes, vitamins, and metabolites are antioxidants ; skin cells have built in antioxidants to protect against sun damage but their ability to protect deteriorates it’s sun exposure

GLYCATION

• Caused by an elevation in blood sugar

• the binding of a protein molecule to a glucose molecule resulting in the formation of damaged, nonfunctioning structures (known as advanced glycation end products or AGES)

• Glycation alters protein structures and decreases biological activity

• Contributes to the aging of the skin, wrinkles and hyperpigmentation ; many age-related diseases (arterial stiffening, cataracts, neurological impairment) are partially attributed to glycation

• Anything that causes a rise in our blood sugar results in inflammation on a cellular level (our body goes into an inflammatory state)

• When sugar rises rapidly and continually, the sugar can attach to collagen in the skin (making it stiff and inflexible) leading to sagging and stiff skin

MICROCIRCULATION

• the circulation of blood from the heart to arterioles (small arteries), to capillaries, to venules (small veins), and then back to the heart

• Hormonal changes are 1 cause of microcirculation problems common in mature skin

COUPEROSE SKIN

• telangiectasia

• The cause is aging the effect is capillary damage

• Redness

• Capillaries that have been damaged and are now larger, or distended blood vessels

• The dilation of the capillary walls

• As the endothelium (wall of the capillary) atrophies and loses elasticity, the walls dilate and fill with blood, sometimes bursting

ROSACEA

• Chronic condition that appears primarily on the cheeks and nose and is characterized by flushing (redness), telangiectasis (distended or dilated surface blood vessels), and in some cases, the formation of papules and pustules

• Chronic vascular disorder characterized by varying degrees of skin redness and congestion of the skin

• Acneic rosacea includes papules and pustules

• In some cases, rosacea may be caused by parasitic microorganisms (mites)