Skin cells

When we are talking about skin, there are about 3 different layers, or Sections. They are the Epidermis, Dermis, and Hypodermic. The epidermis is the outermost superficial region Of the skin. The dermis is the middle region, and the Hypodermic is the deepest region of the skin. As shown below...

The epidermis is made up of Keratinized squamous epithelial, that can then be divided into four different cell types (Keratinocytes, Melanocytes, Merkel cells, and Langerhans cells). Keratinocytes produce the fibrous protein keratin. Melanocytes produce the brown pigment melanin. Langerhans' cells produce the Epidermal macrophages that help activate the immune system. Merkel cells act as touch receptors in association with sensory nerve endings. there are a few layers of the Epidermis, including the Basal layer. it is the Deepest layer of the Epidermis and is attached to the Dermis. It consists of a single layer of the youngest keratinocytes, which undergo a rapid division and that alternate its name (stratum germinativum). There is also the Stratum Spinosum (prickly layer), where Melanin granules and Langerhans' cells are running free! Each cell contains a web like system of intermediate filaments attached to the Desmosomes. Next we have the Stratum granulosum (granular layer), which has 3-5 thin cell layers where changes of keratinocyte's appearance occur. An Accumulation of keratohyaline and lamellated Granules happens in the cells of this layer. On to the next layer, formally knows as stratum lucidum (clear layer). This layer is made up of flat rows of dead keratinocytes cells. This layer is a transparent band to the granular layer. The final layer of the epidermis is the stratum cornium (horny layer). This layer is known more commonly as the outside of your skin. This layer accounts for 3/4 of the epidermal thickness. It also helps to waterproof the body, and protects from abrasions and penetrations. It even renders the body relatively insensitive to biological, chemical, and physical assaults on the body. That is it for the Epidermis layer...YAY!! Time for the Dermis...muahahahaha. The Dermis is the 2nd major skin region which contains strong, but flexible connective tissue. The cells in this payer consist of Fibroblasts, macrophages, and a few mast cells and white blood cells. It has 2 main layers, the papillary and reticular. The Papillary layer has Areolar connective tissue with collagen and elastic fibers. It has a superior surface that contains peg like projections called dermal papillae. That dermal papillae contains capillary loops, Meisser's corpuscles, and free nerve endings. Whereas the Reticular Layer accounts for approximately 80% of the thickness of skin, Collagen fibers make this possible because they add strength and resiliency to the skin. Elastic fibers provide the stretch-recoil effect on your skin. Thus ending our nice little chat about the Dermis...The Hypodermis is a Subcutaneous layer deep inside the skin, composed of adipose and areolar connective tissue.

All these skin layers help to define what "race" you are, due to a few things located in the skin. Melanin, which shifts from yellow, to reddish-brown, to black. It is associated with darker skin colors, meaning the darker your skin, the more melanin is located inside you. Freckles and pigmented moles are a result from little melanin "pockets" on your face...or wherever your freckles and pigmented moles are. There's Carotene, which is yellow and orange pigmentation of the skin. Carotene is most seen on the palms of your hands, and the soles of your feet. Now it is Hemoglobin, which turns people red, or gives you the pinkish "blush" color. It doesn't make you blush, it just makes you look pinkish. Blushing comes from a rush of blood to your face when you get embarrassed. Although there may be a differentiation in skin colors, there is one thing that almost all people in the world have in common, and that would be sweat glands. There are different types of sweat glands, such as the eccrine sweat glands, the Apocrine sweat glands, the ceruminous glands, and the mammary glands. The Eccrine sweat glands are located on your palms, soles of your feet, and your forehead. The Apocrine sweat glands are found in axillary and anogenital areas of the body. The Ceruminous gland is like a modified apocrine gland that is located in the external ear canal and secrete cerumen (ear wax). The mammary glands are specially made sweat glands that secrete milk. The Sebaceous glands (didn't mention above) is a simple alveolar gland that is found all over the body, and it soften your skins when it is stimulated by hormones. Occasionally it will secrete an oily substance called Sebum. Those are some somewhat positive things about the skin, and now the sad and depressing one, cancer.

There are 3 major forms of cancer that occur on your skin, Basal cell carcinoma, squamous cell carcinoma, and melanoma. The basal Cell Carcinoma is the least malignant and the most common of skin cancers. It's cells proliferate and invade the dermis and hyposermis, slowly growing and don't really metastasize. This type of cancer is cured via surgery in about 99% of skin cancer cases. The Squamous cell Carcinoma comes from the Keatinocytes of the stratum spinosum, and are most often on the scalp, ears, and lower lips. It will grow rapidly if it isn't removed quickly, and will metasize if not removed. The prognosis is good if treated by radiation therapy, but cutting it out works to. Preferably letting a surgeon cut it out...unless you know what your doing of course. Melanoma is the cancer of melanocytes and is the most dangerous of all the skin cancers. Seeing as how it is highly metastatic and chemotherapy doesn't work on it, it makes it extremely difficult to find some sort of cure. There are ways of identifying this cancer, using the ABCD rule. A: Asymmetry; the 2 sides of the pigmented area do not match. B: Border is irregular and exhibits indentations. C: Color (pigmented area) is black, brown, tan, and sometimes red or blue. D: diameter is larger that 6mm (size of a pencil eraser). Melanoma is normally treated by surgery with a side of immunotherapy, although the chance of survival is poor is the melanoma is over 4mm thick. Those are only 3 of the main cancers.

Time for some of the scariest kinds of injuries of the skin, Burns. There are 3 degrees of being burned, first, second, and third. In a first-degree burn, only the epidermis is damage, although it is accompanied by redness, swelling, and some pain. A second-degree burn on the other hand, damages the epidermis and the upper regions of the dermis. They include the symptoms of a first-degree burn, but they have blisters. In a third-degree burn, the entire thickness of the skin is damaged, and the burned area appears gray-white, cherry red, or black. There is no initial edema or pain, because it had destroyed whatever nerve endings were in the burned area. Doctors use the "rule of nines" in order to estimate the severity of ones burns. If over 25% of the body is covered in second-degree burns, then it is considered critical. If over 10% of the body is covered in third-degree burns, then that is critical. Although if there are third-degree burns on your face, hands, or feet, they automatically consider that critical. http://www.youtube.com/watch?v=CJt7XySKqYI <--This link will take you to a video that explains how to treat a second and third-degree burn. That would be skin, stay tuned for hair!!