Structure of Skin
In the integumentary system there are three major layers. The dermis, the epidermis, and the hypodermis are these three layers. Here are there functions and some of the parts of each layer.
The bottom layer of the epidermis is the basal layer. This layer is attached to the dermis and is the deepest epidermal layer. This layer has all of the youngest keratinocytes. Cells divide which gives this layer the name Stratum Germinativum.
The next layer is called the Prickly layer. This layer contains a weblike system of filaments attached to desmosomes. There are alot of Melanin granules and Langerhans' cells in this layer. It is also called the Stratum Spinosum.
The third layer is called the Granular Layer.This is a very thin layer where big changes in keratinocyte appearance happens. In this layer Keratohyaline and lamellated granules accumulate. This layer is also called Stratum Granulosum.
The fourth layer is called the clear layer. It is a clear layer that is superficial to the Granular Layer. It consists of a couple layers of dead keratinocytes. This layer is only present on think skin such as on the palm of your hand. This layer is also called the Stratum Lucidum.
The fifth and top layer is called the Horny Layer. It is by far the thickest taking up seventy five percent of the epidermis. Its functions include waterproofing, protection from abrasion and penetration, and rendering the body relatively insensitive to biological, chemical, and physical assaults. This layer is also called the Stratum Corneum.
The Dermis has two main layers
The next layer in the skin is called the Dermis. It is composed of two different main layers. This layer is made of strong, flexible connective tissue. The cells in it are fibroblasts, macrophages, and white and mast blood cells. The two layer of the Dermis are papillary and reticular.
The top layer in the Dermis is called the papillary layer. It consists of Areolar connective tissue with collagen and elastic fibers. It has piglike things called dermal papillae which has capillary loops, Meissners corpuscles, and free nerve endings.
The bottom layer in the Dermis is called the Reticular Layer. This layer is eighty percent of all of skins thickness. It consists of collagen fibers which gives it strength and resiliency to the skin which makes it strong but also very elastic.
The Hypo Dermis is the last layer of skin and is very think. It is used for insulation and is made from adipose and areolar connective tissue.
Tattoos
Tattoos are always something that I've wondered about. How do they work? From my research the tattooist uses a machine that penetrates the skin with a need that travels 50 to 3000 times per minute. The ink that goes into the skin appears on the epidermis, but it is actually place in the Dermis. This is because the Dermis properties are alot more stable so the ink will not move. In fact there is hardly any fading through a lifetime.
The next layer is called the Prickly layer. This layer contains a weblike system of filaments attached to desmosomes. There are alot of Melanin granules and Langerhans' cells in this layer. It is also called the Stratum Spinosum.
The third layer is called the Granular Layer.This is a very thin layer where big changes in keratinocyte appearance happens. In this layer Keratohyaline and lamellated granules accumulate. This layer is also called Stratum Granulosum.
The fourth layer is called the clear layer. It is a clear layer that is superficial to the Granular Layer. It consists of a couple layers of dead keratinocytes. This layer is only present on think skin such as on the palm of your hand. This layer is also called the Stratum Lucidum.
The fifth and top layer is called the Horny Layer. It is by far the thickest taking up seventy five percent of the epidermis. Its functions include waterproofing, protection from abrasion and penetration, and rendering the body relatively insensitive to biological, chemical, and physical assaults. This layer is also called the Stratum Corneum.
