Skin layers and type of skin layers
In the skin, there are three layers: the epidermis, the dermis, and the hypodermis. Epidermis It is the outermost layer of skin. The skin’s tone is determined by this waterproof barrier. It performs the following functions:
- Creating new skin cells
- Giving the skin its color
- Protecting the body from the outside world.
Over the course of four weeks, the epidermis makes new cells in its lower layers. A new layer of cells replaces the dead ones, making their way to the surface and becoming hard.
A keratinocyte is the most common type of epidermis cell, which protects the body against bacteria, parasites, fungus, viruses, heat, ultraviolet rays, and water loss.
Following are the 5 layers of the epidermis:
- stratum corneum
- stratum lucidum
- stratum granulosum
- stratum spinosum
- stratum germinativum
The basement membrane is a thin layer of fibers that divides the epidermis from the dermis.
A dermis is a tissue that connects the skin to the body and protects it from stresses and strains. It grants strength and elasticity to the skin. In addition, a dermis plays the following functions:
- to make sweat and oil
- to provide sensation and blood to the skin
- to grow hair
In addition to housing hair follicles, blood vessels, and lymphatic vessels, the dermis also contains sweat glands and sebaceous glands, which produce oil that protects and lubricates the hair.
Further, the dermis is divided into two layers:
There is loose connective tissue in the papillary region of the dermis. The papillary area has finger-like projections that push into the epidermis.
The skin’s reticular region consists of dense, irregularly-organized connective tissue containing protein fibers that provide strength and elasticity.
Subcutaneous tissue of the skin is also known as the hypodermis or the subcutis, and it provides nerves and blood supply to the skin. While not technically part of the skin, subcutaneous tissue does play an important role in attaching the skin to bones and muscles. There are usually high levels of fat and connective tissue in the hypodermis, as well as elastin, a protein that helps tissues return to their normal shape after stretching. Bones and muscles are also cushioned by the fat layer.
Functions of the skin
Skin plays many roles, including:
- .As part of the immune system, Langerhans cells in the skin protect against pathogens.
- Water and lipids are stored here.
- Creating sensation by detecting temperature, pressure, vibration, touch, and injury through nerve endings.
- Preventing evaporation of water to control water loss.
- The skin is protected against water loss by preventing the loss of nutrients
- Helping to regulate body temperature by producing sweat and dilation of the blood vessels. “Goosebumps” and constriction of the blood vessels help people retain heat.
Skin color is determined by melanin, a pigment. Melanin is a phenotype, which is an observable characteristic. Sun exposure causes melanocytes to produce melanin, which creates a suntan. Melanin protects skin from damaging UV rays from the sun, which can cause skin cancer. A person with more eumelanin has a darker skin tone, while a person with more pheomelanin has a paler tone. Researchers have discovered historically, populations closer to the equator historically evolved darker skin as a means to better protect themselves from UV rays. To maintain Vitamin D, people in colder climates evolved lighter skin.
The skin of women tends to be lighter than that of men, possibly because women need more calcium during pregnancy and while breastfeeding, and because vitamin D is produced when the skin is exposed to sunlight.
The skin is susceptible to certain diseases, just like any other organ of the body. These include:
Atopic dermatitis: The condition produces patches of itchy, dry, red skin that are also known as eczema.
Acne: A variety of skin disorders can cause hair follicles to become clogged with oil and dead skin cells.
Melanoma: Excessive sun exposure causes this type of skin cancer.
Rosacea: People with this rash tend to flush frequently and have small red bumps on their faces in the center.
Psoriasis: There are red, flaky patches on the skin as a result of this auto-inflammatory disease.
Scabies: The human scabies mite causes an itchy skin condition.
Shingles: This rash is caused by a virus and is painful and blistering.
Lichen planus: There are flat shiny bumps on top of this rash. It is not infectious.
An individual’s skin changes with age. It thins out and is more easily damaged. The epidermis replaces dead skin cells less quickly, and the healing process becomes slower. Overall, the skin becomes less elastic and the person has less skin. As we age, our skin becomes more dry, irritated, thin, and prone to infection. As we age, our skin may also become more prone to bruising, itching, and becoming infected.