 |
| cc:gg |
 |
| cc:gg |
The Three Main Functions of the human being Skin
The human being skin
have widely variation of its functionalities and capabilities, which aids the
body to work perfectly. Here is The
Three main functions of the human being skin which is for Protection, Sensation
& Regulation and others.
The human being skin
or integumentary system is the largest organ of the human body and is
approximately 16% of a person's body weight. The human being skin's function is to keep our insides in and the
outside world out (Protection). Also the
three main functions of the human skin is that it protects us from heat,
cold and injury. It is also a sensory organ that tells us when things are too
cold or too hot, too sharp or too close and allows us to feel things with our
fingers (Sensation).
The human being skin
has mechanisms that help us to cool down and warm up. For example when the
weather is cold, the blood vessels in our skin constrict to redirect blood to
our vital organs, to keep them warm. Goosebumps help keep us warm by forming a
layer of erect hair to retain heat. When the weather is warm, the blood vessels
dilate or expand to send blood to the surface of the skin to cool down.
Sweating, another function of the skin, also helps to cool us down. All of
these mechanisms are a form of thermoregulation.
The human being skin
consists of 3 major regions.
1. Epidermis
2. Dermis
3. Hypodermis or subcutaneous
Now let’s talk of The Epidermis
The Epidermis is made up of epithelial cells in 4 distinct
layers over most of the body except the hands and feet which have an extra
layer. The layers of the skin are:
Basal layer or Stratum Basale is the deepest layer of the
epidermis. It is a single row of epithelial cells called Keratinocytes which
are constantly dividing and sending new cells up into the next layer. This
layer contains melanocytes and merkel cells.
The next layer is the spinous layer or Stratum Spinosum. It
is the thickest layer of the epidermis and here the keratinocytes spread out
and lock in to all the other keratinocytes creating a kind of patchwork quilt
of oddly shaped cells. As many of the joins are at sharp angles, this is
nicknamed the spiny layer. Melanin granules and Langerhan's cells exist in this
layer.
The Stratum Granulosum or Granular layer is the next layer
towards the surface. This layer is less dense than the Spiny Layer as the cells
flatten out and become more compact. The Granular layer is where fibres called
keratin filaments start to gather together and lipids (fats) accumulate to
prepare the layer to fulfil its job of protecting the body. It is at this point
that the cells is no longer living.
The Stratum Lucidum or clear layer is only present on the
palms of the hands and soles of the feet. It is made up of dead cells that look
clear under a microscope. It gives an extra layer of protection and flexibility
to areas of most friction which also makes up the three main function of the human being skin.
The Stratum Corneum is the thick, outermost layer of the human being skin and consists of dead,
keratinatised cells called corneocytes. The cells are bound together with
connectors called desmosomes and their function is to protect the deeper layers
from water and injury. The Stratum Corneum is constantly sloughing off its
outer cells while being replenished from below.
The Dermis
The dermis is connective tissue. Connective tissue is a
supporting framework. Its main components are Collagen, Elastin and Ground
Substance.
The Dermis supports and strengthens the epidermis and is
made up of connective tissue. It has 2 layers. They are not clearly defined as
in the epidermis but rather a continuum, from the papillary dermis near the
epidermis, to the reticular dermis below it, which then merges with the
subcutaneous tissue.
Layers of the Dermis
The Papillary Dermis
as regards to the three main
functions of the human being skin
The Reticular Dermis as regards to the three main functions of the human being
skin
The
Papillary Dermis
The Papillary Dermis is the thin upper layer closest to the
epidermis. It is called the papillary dermis because it projects papillae
(nipple-like structures) into the epidermis. This fixes the dermis to the
epidermis so they don't slide over each other. The Papillary Dermis contains
Capillaries - which provide nutrients to and remove waste from the cells of the
epidermis which is one of the three main
functions of the human being skin.
The Reticular Dermis
The Reticular Dermis is the largest part of the dermis and
it contains many structures such as hair follicles, sebaceous glands, sweat
glands, nerves, blood vessels, lymph vessels, muscles and other glands. This
layer gives strength and resilience to the skin because of the presence of a
scaffolding of Collagen and Elastin fibres in a kind of syrup called Ground
Substance.
The Hypodermis or subcutaneous tissue
The Hypodermis is the tissue that lies under the dermis. It
is mainly made of adipose tissue (fat), connective tissue and blood vessels but
many of the structures of the human being
skin such as hair follicles, glands, nerves and muscles extend to this
area. The hypodermis anchors the dermis to the underlying fascia (layers that
surround body structures such as bones and muscles). The reticular dermis
blends into the hypodermis rather than the two being well defined separate
layers. Now that we have finished all about the three main function of the human being skin
