Integumentary System

Integumentary system is also known as our "skin". It serves as a protection from foreign agents aside from the immune system. This is the first line of our defense. Without it, our white blood cells may not be able to perform their tasks well from defending our body. The skin also serves as storage for vitamin D and provides sense of touch which allows us to detect danger and pain in an environment. What's more amazing about our skin is that it can adapt and adjust our temperature in different environments.

The skin is divided into three layers. First is the epidermis which is the skin itself. Though it has no blood vessels, it contains dead skin cells which are to be replaced by new skin cells when it is damaged. Dermis is the second layer of the skin which is considered to be the "true skin". Because it contains blood vessels and has dense connective tissues surrounding. It also has elastic fibers which when we try to pull our skin it forms back like what Mr. Fantastic does from the Fantastic 4. Finally, the subcutaneous fascia, the innermost layer, has still elastic fiber to support the dermis but has lipocytes for insulation and padding that are attached to the muscles.

Of course, the integumentary system wouldn't be complete without the aid of sweat glands. Sweat glands are also part of the skin which acts as storage and carries out heat away from the body. There are two types of sweat glands. Apocrine glands are the ones which are secreted at the hair follicles while eccrine glands are secreted all over the skin and not from hair follicles.

We may be wondering how the skin heals itself. Well first, when the skin is wounded it calls out the platelets to clot the wounded part. Then as it clots it hardens and forms a scab. After a scab is formed white blood cells then took place in guarding the scab from foreign agents causing infection. While the white blood cells are guarding, the production of new cells form and then the skin is healed.

How about if the skin is burned? It is really dangerous isn't it? Obviously it is, and it is a main threat for the skin. There are depths of burns at which point the skin can be damaged.
1st burn - partly epidermis, no pain, takes 2-3 days to recover
2nd burn - entire epidermis and portion of the dermis, redness, pain, and blisters, takes 10-14 days of recovery
3rd burn - all three layers that can't be felt any pain
4th burn - affecting the bone

Other parts of the integumentary system are the nails and hair. Nails are specialized cells orginated from the nail root while hair is composed of kerotin and melanin that makes our hair turn color black. Melanocytes and melanin are the ones responsible for the color pigment of our skin and hair. Carotenes are the ones which makes our skin yellow from the yellow race or the Mongolians.