On one square meter of skin, the most sensitive of all human organs, there are:
- 10 hair follicles
- 100 sweat glands
- up to 2500 sensorial cells
- 3 meters of lymphatic and blood capillaries
- 12 meters of nerve fibers
- and not less than 1000 billion microbes. Yuck!
Lots of Bacteria on the Skin's Surface: Nothing Can Hide from an Electronic Microscope
Friendly Bacteria
1000 billion microbes per one square meter of skin – that’s a lot! Luckily, under normal, healthy conditions most of these bacteria are not harmful. Some of them are even the skin’s partners. They feed upon dead cells and sebum and, by keeping other undesirable bacteria from developing, they act as cleaners.
Breathtaking!
One square centimeter of the epidermis contains 10 million cells. 85% are keratocytes (that act as barriers), 5% are melanocytes (to give skin its color and aid in tanning), from 2 to 5% are Langerhans cells, , from 6 to 10% are Merkel cells (cells that carry the sense of touch) and from 0.5 to 1% are nerve cells (for sensorial communication).
Skin Sings!
Did you know that your skin “sings” when you touch it? Interested in hearing a few “skinsongs”?
The Surface of the Skin Under an Electronic Microscope…Practically Unrecognizable
Time for a Diet!
18% of our body mass comes from the weight of the skin. The hypo-derma’s mattress of fat alone accounts for 60% to 85% of our body weight.
Variable Geometry
Skin does not have the same thickness everywhere on our body. The skin on our back is the thickest (4 millimeters), followed by that on our thighs (approximately 2.6 mm), our stomach (2.5 mm), our forehead (1.9 mm), our wrists (1.7 mm) and our scalp (1.2 mm). The thickness of the epidermis is practically the same on every part of our bodies (less than 0.1 mm), with one major exception: the palms of our hands. Although the skin itself is slightly thinner than that of our wrists (about 1.5 mm), the stratum corneum (the epidermis) is practically 0.5 millimeters thick, or five times thicker than it is anywhere else!
Collagen and elastin fibers under an electronic microscope
Full of Fibers
70% to 80% of the derma’s dry weight comes from the collagen (or elastic) fibers that act as its support. This network of fibers is, in large part, what allows skin to move, change form and stretch.
In order to break a collagen fiber that is only 1 millimeter in diameter, you must apply a force of 10 to 40 kilos!
As Thirsty as a Camel
One-fifth of the water content of an adult body is found in skin: from six to eight liters! This amount varies with age.
57% of this water is found in the derma, the other 13% is found in the epidermis.
A Steam Engine
Without our being aware of it, we lose 100 milliliters of water per day. That is what is called unfelt water loss.
Through capillary evaporation, we lose 9 grams of water per square meter of skin every hour, without even knowing it.
The Surface of the Moon? No, Orange peel looking skin due to underlaying fat deposit
A Comforting Thought
You’re not alone! 80% to 95% of women have problems with cellulite. Isn’t that a comforting thought? We hope it relieves a little stress because that very stress is what generates hormonal discharges that, in turn, contribute to the growth of our “fat mattress”!
Go Defense!
Microbes and bacteria know that skin is a tough customer and that attacking skin is risky business. Perspiration and sebum form a protective film with an acidity level that is strong enough to destroy weaker undesirables. To deal with stronger aggressors, the Langerhans cells that are located in the epidermis take over. If the skin were a football field, these cells would be the linebackers.
These immune cells were first discovered in 1868 by a twenty-one year old medical student from Berlin, Paul Langerhans. They capture foreign substances and transmit this information to the lymph cells in the derma. This is what triggers the body’s immune system. The moral of the story: It’s better to have the Langerhans working for you than against you!
Hairy Palms!
Finding a hair in your palm would really be a physiological miracle, since the palms of our hands contain no hair follicles. However, they do have lots of sweat glands. You know, the ones that make your hands sweat when you get nervous!
Pilled up corneocytes of the Horny layer
Zombie!
Strange, but true: the keratinous layer of the epidermis, the skin’s protective barrier and the visible layer we usually think of as skin, is entirely made up of dead cells!
Every day, 300 million skin cells are renewed.
The skin loses from 9 to 17 milligrams of dead cells per day. This is referred to
as desquamation.
From http://www.loreal.com/
