Human body is a combination of various organ systems. Every organ system has its own working machinery define like hands to work, eye to notice, mind to think etc. Out of all the skin which is also called integumentary system is the largest part in our body. Skin is the outermost part in the body. Skin has a biggest role in saving us from atmosphere gases, pollution, ultraviolet rays and undesirable conditions.
Parts of skin
Skin is basically divided into three parts
- Subcutaneous tissue(Hypodermis)
Epidermis is outermost part of the body made from germinal cells, dead cells, live cells. Epidermis has its four sub parts
- Stratum germinativum
- Stratum basale
- Stratum spinosum
- Stratum granulosum
- Stratum lucidum
- Stratum corneum
These layers points inside towards outside starting from stratum basale to stratum corneum that is why new skin build up takes average of 28 days. Same procedure is apply in case of medicine too. In case of skin disease medicine take at least average same days to show their effects.
Special cells of epidermis
- Langerhans cells
Melanocytes are responsible for deciding the color pigmentation of skin. Melanin deficiency and excess is the cause of different skin colors. If Melanosome in melanocytes is smaller in size color will be fair and if it is wide skin color will be black. Excess of Sun light cause deficiency of melanin. Lucoderma a skin disease is an example of loss of pigmentation due to deficiency of melanin. In which on skin white patches produce.
Keratinocytes responsible for create hard protein on skin for example nails. Keratinocytes are act as intact barrier.
Langerhans cells save us from bacteria by fighting them. Langerhans cells are found in granular layer having dendrites.
Dermis is somewhat thicker layer next to epidermis. Dermis is made from blood vessels, nerve endings and connective tissues. Generally it works as a nutrient supplier for epidermis. Collagen and elastin are its part which is present in flexible parts of the body like abdomen, knee. Skin stretching and pressing is because of these cells. Collagen oppose stretch. In old age due to presence of dead cells in the body elastins finishes slowly resulting creates a wrinkles on body.
Sebaceous glands(fatty tissues) creates a layer and maintain water in equilibrium on skin surface. Sebaceous glands secretes sebum an oily substance. Sebum save from fungal infection and dry skin. It keeps the skin moist. In adulthood due to harmones increase the level of sebum. Sebum then covers the follicles by combining with dead cells which results in acne. Deficiency of sebum cause dry skin.
Sweat glands is a mixture of water, salt, lactate ion. Lactate ion is lovable to mosquitoes. In skin there are about 50 million glands also called sudoriferous gland.
Works of skin
- Sweat glands help to control water level in the body.
- Protect internal organs
- Skin has a direct connection with personality.
- Skin feels and save us from environmental changes
- Protect from ultraviolet rays.
- Help in synthesis of vitamin D.