SKIN CARE AND PRESERVATION

July 10, 2015

Blood and lymph vessels, nerves and specialised cells play a vital role in triggering the skin’s inflammatory response to invading bacteria, allergies and physical injury. Blood vessels in the dermis help to regulate heat by constricting or dilating to conserve or release the body’s heat. They also aid immunity and give oxygen and nutrients to the epidermal layers. Nutrients diffuse only into the very bottom layers as blood vessels do not extend into the epidermis. Dead cells in the upper layers do not receive oxygen and nourishment.

A wave like border at the junction between the dermis and the epidermis provides an increased surface for this exchange of food and oxygen between the two sections. Along this junction are projections called dermal papillae. They tend to flatten with ageing as the flow of oxygen and nutrients decreases.

Stratified into five horizontal layers the epidermis as the topmost layer actually consists of between fifty cell layers in the thin areas to one hundred cells in thickness, on average 0.1 millimetres, similar in fineness to a leaf. Complete renewal of the cells occurs monthly in the epidermis which acts as a protection for the body. A single layer of cubed cells sits directly on top of the dermis in the deepest or first epidermal layer, the stratum basale. New skin cells called keratinocytes are formed in this layer through cell division to replace those shed continuously from the upper layers. The rate of this regenerative skin cell renewal decreases with ageing.

Melanocytes in the basement membrane produce the skin pigment melanin, which is photo protective against the skin’s exposure to ultraviolet rays in the sun. From the melanocytes, melanin transfers to nearby keratinocytes that will eventually migrate to the skin’s surface.

The second epidermal spinous or prickle-cell layer, the stratum spinosum, has polygonal, many sided keratinocytes. These lie in about eight to ten layers which begin to become rather flattened.

Keratin, a tough fibrous protein giving skin its protective property comprises the third or granular layer, the stratum granulosum. Flattened cells in these three to five layers begin to die as they are too far from the dermis to receive nourishment by diffusion. Making up the outer layer of skin, keratin is the key structural material of hair and nails and it provides the necessary strength and toughness for masticatory organs, such as the tongue, gums and hard palate.

A fourth epidermal layer of extremely flattened cells in three to five layers is called the stratum lucidum. This clear layer makes up only fingertips, palms and soles of the feet.

Dead keratinocytes are flattened in twenty five to thirty rows in the top outermost horny layer. This fifth layer, the stratum corneum is the real protective part of the skin, shedding keratinocytes continuously by friction and replacing them by cells from deeper epidermal sections.

Lipids, ceramides and fatty acids in between the keratinocytes in the horny layer act as cement around the skin cells. A combination of keratinocytes interspersed with epidermal lipids forms a waterproof barrier to keep moisture in the skin. Loss of the balance of oil and moisture in the skin to protect against bacteria causes dryness, itching, redness, stinging and skin problems.

Acidity helps maintain the hardness of keratin proteins keeping them tightly bound together. If the skin’s surface is alkaline, keratin fibres loosen and soften, losing its protective acidity. Skin becomes dehydrated, and infection, roughness, scaliness and other irritations appear. Slightly acidic moisture layers are derived from the combined secretions of sebaceous and sweat glands, inhibiting the growth of harmful bacteria and skin blemishes.

Hair, sebaceous and sweat glands are common components of both the dermis and epidermis. Pores are formed by a folding in of the epidermis into the dermis.

Dead keratinocytes, the skin cells that line the pore are constantly being shed like the epidermal cells at the top of the skin. The lining of the pore loses keratinocytes which, mixed with the sebum, clog the pore forming eruptions on the skin surface. Oil builds up inside the pores, disrupting surrounding tissue and pores begin to enlarge. When the skin loses its protective balance of oil and moisture or becomes alkaline, skin eruption results. Hair growth out of the pores is composed of dead cells filled with keratin proteins. A bulbous follicle at the base of each hair divides to produce new cells. The follicles are nourished by tiny blood vessels and glands. Hair prevents heat loss and helps protect the epidermis from exposure to the sun’s rays.

Sebaceous glands connected to hair follicles secrete sebum to help lubricate the follicle as it grows. Sebum, the oily liquid produced within the sebaceous glands is regulated by hormones and contributes to the lipids and fatty acids in the moisture balance.

Perspiration excreted by sweat glands is acted upon by bacteria producing a characteristic odour and helps cool the body temperature, hydrate the skin, eliminate some toxins, mainly salt. Long coiled hollow tubes of cells produce sweat either by ductless glands below the epithelial surface or by long portions of a duct on apocrine and exocrine glands secreting directly to the pore opening on the skin surface and by eccrine external secretion regulating body heat.

Understanding how the skin functions and is constructed can help you better care for a healthy skin.

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EPIDERMIS AND DERMIS

July 10, 2015
Five layers of the epidermis

Epidermal layers

DERMIS AND EPIDERMIS

July 10, 2015

Fibroblasts are cells located in the upper edge of the dermis bordering the epidermis and are specialised in producing the skin’s collagen and elastin. Collagen proteins found in the skin, as well as in cartilage and bone, form a mesh like framework in the dermis to give the skin strength and elasticity. Moisture binding molecules called glycoproteins enable collagen fibres rich in glycine, to retain water and give moisture to the epidermis. Another coil like connective tissue protein, elastin, which has a high percentage of both glycine and alanine, is found in the dermis giving the skin its ability to return to the original shape, or its elasticity.

Keratins, which have larger amounts of the sulphur-containing amino acid cysteine, assemble into bundles to form intermediate keratin proteins capable of annealing end-to-end into long filaments. These are tough and form unmineralised tissues. Derived from the Greek root kerato meaning “horn like”, filaments called keratin abound in keratinocytes in the cornified layer of the epidermis and are present in epithelial cells in general. These are cells which have undergone keratinisation. For example, thymic epithelial cells are known to react with antibodies for keratin in the thymus.

Combined into “hard” or “soft” cytokeratins, proteins are understood to occur as either neutral basic or acidic keratin in the skin’s stratum corneum of the stratified epithelial layers, cornea of the eye, squamous epithelia and ducts as well as the simple epithelium. More flexible and elastic keratins of the hair are harder and consist of coiled single protein strands which are then twisted helically into ropes that may be further coiled.

SKIN AS INTEGUMENT

July 10, 2015
Ageing skin

Skin’s collagen and elastin

Great lies of our time: “journalists and coders should sit together to create amazing stuff” (updated)

June 6, 2015

The silence of the computers overtook the thunderous noise of linotype machinery.

The Overspill: when there's more that I want to say


The Thomson Reuters newsroom. Note papers stacked all over the place. No idea if journalists and developers “sit together” here – but I’d bet they don’t. Photo by Targuman on Flickr.

I keep seeing people saying “you know how journalism and the internet can work better? Have the news org’s journalists and coders sit beside each other. Wonderful things will happen.”

Postscript, but at the top: this post generated a lot of reaction – so be sure to read the followup, which pulls together the many people saying that it can and does work./Postscript.

Let me tell you: when someone spins you this line, it’s pure unadulterated 100% bullshit. Anyone who says this has never looked at what happens when you do this, or considered the differences in work patterns between the two. (It pains me to point out that Wolfgang Blau is only the latest to suggest…

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LYMPH NODES

June 3, 2015

Lymph is important for the skin and is formed by a white pulp. Lymph moves by the action of breathing and squeezing by the movement of the muscles. By continuous variation in the pressure of fluid in the tissues, the movement of the lymph accelerates the activity of endothelial cells as well as increasing the […]

http://milenapetrofig.com/2014/05/23/lymph-nodes/

CAN A TEENAGER FIND THE CURE FOR ACNE?

June 3, 2015

Sometimes teenagers rebel against their parents’ advice. At 13, one girl thought her mother was being too ‘pushy’ when she brought her to my salon for treatment. She returned years after with skin scarred and pitted from acne. She remembered her mother bringing her to me, after trying out every treatment around including dermabrasion. This […]

http://milenapetrofig.com/2014/05/21/can-a-teenager-find-the-cure-for-acne/

SEAWEED: A LEGENDARY PLANT

June 3, 2015

The fascination with seaweed began centuries ago. Venus is said to have sprung from the sea in a secret seaweed covered grotto according to ancient mythology. An old Babylonian almanac, ‘Gilgamesh’, tells of a wise man searching for the secret of longevity which noted seaweed as a source of prolonging life. When we consider marine […]

http://milenapetrofig.com/2014/05/22/seaweed-a-legendary-plant/

LYMPH NODES

June 3, 2015

Lymph is important for the skin and is formed by a white pulp. Lymph moves by the action of breathing and squeezing by the movement of the muscles. By continuous variation in the pressure of fluid in the tissues, the movement of the lymph accelerates the activity of endothelial cells as well as increasing the […]

http://milenapetrofig.com/2014/05/23/lymph-nodes/

Gallipoli 16: Who Lives For England Sleeps With God

April 27, 2015

First World War Hidden History

Helles Bay April 1915The Allies managed to land 30,000 men on the Gallipoli Peninsula, but suffered 20,000 casualties in the effort. They held a foothold, but were unable to push forward more than one mile. Ellis Ashmead-Bartlett, a journalist embedded with the British military noted; ‘At Anzac any further advance is out of the question, for the Australians and New Zealanders have as much as they can do to hold on to what they have won. No army has ever found itself dumped in a more impossible or ludicrous position, shut in on all sides by hills, and having no point from which it can debouch for an attack, except by climbing up them’. At Helles, the 29th Division had lost half its number, and Bartlett’s conclusion was that ‘we are barely holding our own on the Peninsula, there is absolutely no question of an advance…’[1]

These men suffered. Arrangements for evacuating the…

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