A. UNDERSTANDING DEFINITION OF THE SKIN
The skin is an organ of the body that covers the
entire human body. Skin weight estimated to be around 7% of total body weight.
On the outer surface of the skin are pores (cavity) which became the
perspiration. The skin is an organ that has many functions, such as body armor
of the various things that can be dangerous, as the senses of touch, as one of
the organs that play a role in excretion, regulating body temperature, etc. In
general, the skin has two layers ; the epidermis and the dermis and there is a
layer of fat under the skin (hypodermic) which also frequently discussed. Some
sources say that the fat layer under the skin is also included into the skin
layer, not separated from the skin layer grouping.
 |
| THE SKIN |
B. THE FUNCTIONS OF SKIN
1. As the Body protection from threats
As the outermost part of the body, skin protected the
body from various threats such as harmful microorganisms, sunlight, reducing
the damage caused by a stroke, and to protect the direct contact with chemicals.
2. As a sensory to Touch
In the skin there are many end of the innervation of
the body, therefore when it gets stimuli, we can feel it through our body.
Examples such as the stimulation of touch, heat, cold, pain, etc.
3. As excretion Tool
Skin is an exretion tool for sweat (prespiration),
perspiration is a metabolic waste consisting of various elements that are no
longer needed by the body. Approximately 1 liter of sweat a day, are removed
from the pores (small hollows on the surface of the skin).
4. Controling Body Temperature
The skin will continue to keep the body temperature
so we not affected by ambient temperature, meaning that our body temperature
were unchanged despite the change in environmental temperature. This process is
done with the balance between expenditure and inclusion of body heat by the
skin. Normal human body temperature is 36.6 to 37.2 Celcius degrees, and the
skin temperature slightly lower than body temperature.
5. As Fat Storage
The bottom of the dermis layer of the skin acts as a
fat storage. Fat is stored in the form of drops of fat, and the fat that will
be used if necessary, for example when we need more energy, fat will be used as
energy because it also serves as an energy reserve.
6. As a place to metabolism Vitamin D
In the Skin there provitamin D derived from food,
with the aid of ultraviolet light from the sun, provitamin D will be converted
into vitamin D.
C. LAYERS OF THE SKIN
Divided into epidermis layer (Outer layer), dermis (inner
layer), and hypodermic (fat layer)
1. The epidermis layer (Layer Affairs or Skin Ari)
The epidermis layer has a thickness of approximately
0.1 mm and consists of four layers of epithelial tissue. Each layer of the
epidermis has its own characteristics, epidermis layer has no blood vessels, so
that he gets the supply of nutrients through diffusion from the dermis layer
underneath. Here are four layers in the epidermis:
- Horn layer (Stratum corneum), the outermost layer of the skin of the body, this layer continues to experience desquamation (peelling) continuously. Various cells making up this layer will be hydrolyzed Creatine layer, which is waterproof, therefore it is called composed by die cells. This layer is not covered with the blood vessels, the peelling process will be painless and bloodless. This layer serves to prevent the entry of bacteria and reduce the evaporation of the liquid.
- Malpighian layer (granular layer), a layer of skin that is composed by living cells that obtain nutrients from the capillaries in the dermis layer. Malpighian layer is a layer that plays a role in giving color to human skin. The main substance in the coloring of the skin is called Melanin. Surely you already know that skin color can vary, it can be black, white, brown, etc. The accumulation of melanin in one place will be formed black spots and moles.
- Spinosum layer (stratum Spinosum), a layer of skin that is drawn up by various cells of irregular shape. The cells in this layer has the ability to divide. This layer serves to maintain the strength and flexibility of the skin.
- Basal layer (Stratum germ), a layer of skin that continuously keeps dividing to renew the damaged parts of epidermis. This layer is the bottom layer of the epidermis. Basal layer forming new skin so the skin are healthy periodically.
2. The dermis
layer (Leather Hides)
The dermis layer (Inner Layer) is a layer of skin
that is made up of blood vessels, oil glands, hair follicles, the sensory nerve
endings and sweat glands. The blood vessels in this layer is wide so can
accommodate approximately 5% of the amount of blood throughout the body. Here
is the explanation for the part of dermis layer:
- Blood Vessels, is a capillary blood vessels which serves as a conduit of nutrients and oxygen to - skin cells and hair cells. Blood vessels also function in maintaining body heat because of the presence of oxygen in the blood vessels.
- Sensory nerve, consisting of nerve endings tactile and sensory nerve endings. The end of the taste buds can sense stimuli such as touch, pressure, pain, cold, and heat. While the tactile nerve endings can feel rough or delicate things. These nerve endings are not spread evenly throughout the surface layers of the dermis, for example, our Fingertips had more nerve of touch.
- Sweat gland, a gland that serves to sweat excretory system, consisting of water and other minerals. As I mentioned earlier, the sweat brought to the surface through the pores (skin cavity). Sweat is a waste products subsctance, especially salt.
- Hair follicles, a hair section that contains the roots of the hair shaft. Hair can grow as it gets the supply of nutrients from the capillaries into the hair roots. Near the root of the hair there is the muscle that can be straighten the hair when it contracted, and hair roots are near of sensory nerve endings, so when the hair is removed we can feel it.
- Oil gland, a gland located around the hair shaft. oil glands produce oil that serves to keep hair healthy and that hair is not dry.
3. hypodermic
(Fat Layer)
Hypodermic (Fat Layer) is a connective tissue that
lies beneath the dermis layer, but the demarcation between the hypodermic with
the dermis is not clear. This layer is where the fat storage in the body, so it
is often also known as the fat layer of the skin. The fat serves to protect
from impact by hard objects, as the controler of body temperature because the
fat can store heat, and as a backup energy source.
