Interesting Facts about the Skin - Its Functions and Disorders
Know your Body

The Skin

Authored by DesiMD Doctor on 20 Mar 2013 - 18:50

Anatomy:

The skin is the largest organ on the body, and is responsible for covering all surfaces. The consistency of skin varies significantly throughout the body, including differences in texture, color or its thickness. For example, skin on the bottom of the feet or in the palms of the hands are significantly thicker than skin found other places, while skin on the scalp contains more hair follicles than anywhere else.

The skin consists of different layers with each one serving a purpose.
These three layers are:

The Epidermis:
This is the outermost layer of the skin that is in contact with the environment. It is this outer layer of skin that contains cells known as melanocytes, which give colour to the skin (or pigmentation).
This skin layer consists of three different parts which are:

  • The Horny Layer (Stratum Corneum): This is the outermost layer of the skin which prevents contact with foreign bodies and helps to retain moisture. It consists of mature keratinocytes which possess fibrous proteins called keratin that helps to form structural integrity of the skin. This layer is continuously being shed and replaced by layers under it
  • Squamous Cells (Keratinocytes): This layer consists of keratinocytes which are in the process of becoming fully matured to replace the top layer
  • Basal Layer: This is the deepest layer (the base) of the epidermis and contains basal cells which are continuously dividing to form and replace older keratinocytes

The Dermis:

  • The dermis is the middle layer of the skin, which serves as the most functional layer. This layer includes important components off the skin including blood vessels, nerves, hair follicles, glands(sweat), lymph vessels, bundles of collagen and fibroblasts( cells that produce keratin)
  • Collagen gives this layer the most flexibility. This is the layer that actually senses pain or contact

The Subcutaneous Layer: This is the deepest layer of skin, consisting of mainly fat cells and collagen. This layer helps to insulate the body, and also helps to cushion impact, in effect being a natural shock absorber. The thickness of this layer varies greatly with a person’s overall fat level.

Functions of the skin:
The skin is a very important organ to help regulate homeostasis within the body as well as serving many other protective functions.
The functions of the skin can be classified as:

  • Protective Barrier- the skin is the first line of defense the body has to evade contact with pathogens or danger. There are cells on the body called Langerhan Cells which form part of the immune system
  • Sensory Role- the skin in addition to being able to protect the body must be sensitive enough to know when danger lurks. For this reason, the skin contains various types of sensory cells, which may be sensitive to changes in temperature (heat or cold), pain (in response to an injury) and changes in external pressure
  • Insulation- this function of the skin helps to maintain body temperature. It can either promote heat loss and perspiration when the external environment is hot, or reserve heat when the external is cold
  • Maintain Moisture Levels- the skin can be considered a relatively impermeable membrane, in that it only selectively allows substances to pass out. In this aspect, when body fluid levels are low, loss of water through the skin is greatly reduced
  • Storage- the skin in many individuals serves as a reservoir for excess fat and water. These are mobilized in times of need
  • Synthesis of important vitamin- when Ultraviolet light from the sun acts upon certain cells in the skin, vitamin D3 is synthesized. Individuals possessing higher levels of melanin (darker skin surface) are less likely to develop skin cancer since melanin limits the effect of UV radiation on the skin. So contrary to belief, lighter skinned people produce more natural vitamin D3.

Conditions that may affect the Skin:

Due to the sheer size of the surface covering the skin, there are many ailments that may affect the skin.
The most common conditions that may occur:

  • Acne- may occur on any part of the body but mainly occurs on the face and back
  • Athlete’s foot- this is a fungal infection affecting the feet
  • Cysts- there are areas where lymph nodes swell due to collection of lymphatic fluid( commonly)
  • Hair loss (alopecia androgenetica) - this type of hair loss affects mainly men and is genetically linked
  • Moles- generally harmless may be caused by over exposure to sun or through genetics
  • Psoriasis- autoimmune condition whereby skin cells grow too fast
  • Eczema- this is an inflammatory condition affecting the skin sometimes referred to as dermatitis. Has various causes
  • Ringworm- very common infection on the skin due to a fungus, not a worm
  • Scabies- contagious skin infection caused by burrowing mite
  • Dandruff- results via inflammation of seborrheic glands on the scalp
  • Skin cancer
  • Stretch Marks- occur when skin layers expand and fail to retract back to normal
  • Sunburn- this is a condition caused by exposure to too much UV light leading to skin inflammation
  • Warts- due to virus in the body known as HPV( human papilloma Virus)

Interesting Facts about the Skin:

  • Approximately 40000 skin cells die every minute
  • The skin loses about 3 gallons of sweat daily
  • Total length of nerves in the skin is about 45 miles
  • Lips are pink because the skin is very thin and blood vessels show through
  • Your eye is covered by skin too
  • Average weight of skin in an adult is about 9 pounds
  • Breasts are a highly developed type of sweat gland
  • White skin developed by migration of dark skinned people to cold climates
  • Most of the dust accumulating in a closed house is actually dead skin
  • The total number of skin cells shed throughout a person’s lifetime could comfortably build a two story house