The largest organ of the body is composed of three distinct layers, the epidermis, dermis and the subcutaneous fat or the adipose tissues. The epidermis is avascular, which means that it hosts no blood vessels or lymphatic vessels. It is also composed of stratified, squamous epithelial layer. The blood vessels which sometimes contour to our body can be found in the dermis layer of the skin. The level of activity of the keratin-producing epithelial cells is responsive to the needs of the skin and since it is situated in an avascular area, it gets its nutrition by way of diffusion. When we are dehydrated, we may notice the skin to be dry and sometimes shiny, the one undergoing the change is the outer layer of the epidermis.
Mitotic keratinocytes form the stratum basale separated from the dermis with the epidermal-dermal junction. This is the part of the skin that rapidly regenerates. Once new cells are formed, it is pushed upwards gradually by another batch of newly formed cells. Melanocytes produce melanin which is disseminated along the keratinocytes to protect the skin from ultraviolet radiation.
Referred to by medical professionals as the prickle cell layer, this is the fourth layer of the epidermis. It derives the moniker prickle cell layer because of intercellular tonofibrils radiating out from the cell surface. Layers of cuboidal and squamous keratinocytes comprise the stratum spinosum. The Langerhans cell, another kind of dendritic cell can be found in both the stratum spinosum and the stratum basale. The main task of this layer of the epidermis is to engage foreign materials and to present antigen to T-lymphocytes.
This layer is to thank for because it gives the skin its characteristic impermeability. The cells in the stratum granulosum have lost their nuclei and appear to be flattened keratinocytes. A lot of activity happens in this layer as the lipid rich content of the lamellar granules fills the intercellular spaces which greatly contributes to the impermeability of the skin. This layer is situated in the middle, with two layers above and two layers below.
This layer serves a very important role, to maintain skin integrity and the hydration of the skin. It varies in thickness, ranging from five layers as that with the eye lids and as thick as fifty layers with that of the sole of the foot. Understanding the stratum corneum can lead to having an attractive appearance and a healthy skin. Studies reveal that this layer is made up of multiple layers of lifeless, squamous, keratin filled cells.
Even the simplest things do great wonders. This is what the skin has taught all of us. Despite appearing to be just a dull covering of our body, it does involved complex and intricate mechanisms and processes that shield us from harm while keeping us look good.