a girl touching her face

Layers of Skin

Skin

The largest external organ of your body is your skin. It acts as a barrier between the essential organs of the body like tissues, muscle, skeletal system, and the outside world. This barrier acts as a shield to protect you from chemical exposure, bacteria, and change in temperature.

Now Let's Have A Look At The Benefits of Skin

  • It stores fat and water
  • It regulates the body temperature
  • A sensory organ of your body
  • Prevents the intrusion of bacteria 
  • Prevents loss of water 
  • It acts as a barrier between the environment of the organism and the organism itself
  • It helps in the production of vitamin D when it is exposed to the sun

Your skin is a special blanket that takes on different colours, thicknesses, and textures all over the body. For example, there are more hair follicles on your head than can be found anywhere else on your body while the soul of your feet or palm's skin is much thicker than skin found anywhere on your body.

What Is The Epidermis?

The outermost layer of the three layers of your skin is called the epidermis. Its thickness totally depends on where it is found on the body. For example, it is thickest on the palms and soles of your feet is about 1.5 mm while thinnest on the eyelids is about 0.5 mm.

There are five layers of the epidermis in total.

  • 1. Stratum basale: This is the bottom layer, which is also called the basal cell layer, and has column-shaped basal cells which divide and push the older cells towards the surface of your skin and get flatten and then eventually die and shed.
  • 2. Stratum spinosum: This layer contains newly formed strengthening protein keratinocytes and is the thickest layer of the epidermis. 
  • 3. Stratum granulosum: This layer contains a large number of keratinocytes that move towards the surface.
  • 4. Stratum lucidum: This layer found its existence only on the palms of your hand and soles of your feet. 
  • 5. Stratum corneum: This layer is the outermost layer of the epidermis. It is made of dead, flat keratinocytes that are shed every two weeks.

The epidermis contains three specialized cells:

  1. Melanocytes which produce pigment
  2. Langerhans cells act as the first barrier in the skin's immune system.
  3. The Merkel cell's function is still unknown. 

Function of Epidermis

The epidermis is the topmost layer of the skin that can be seen and touched. Keratin is a protein that is inside the skin cells which makes up the skin cells and besides other proteins, it sticks together to form this layer.

The epidermis:

  • Acts As A Protective Shield: The epidermis keeps away germs and bacteria from entering your body and bloodstream.
  • Makes New Skin: The epidermis always keeps on producing new skin cells. These new cells actually replace almost 40,000 dead skin cells that your body sheds every day. You have new shiny and glowy skin every 30 days.
  • Protects your body: Langerhans cells found in the epidermis are a part of your body’s immune system. They help fight off infections and other germs.
  • Provides skin color: The melanin present in the epidermis, the pigment that gives skin its true color. The color of your skin, eyes, and hair is determined by the amount of melanin you have. 

The Dermis

Located between the epidermis and subcutaneous tissues, the dermis is the middle layer of the three layers of your skin. It contains blood capillaries, connective tissue, sweat and oil glands, hair follicles, and nerve endings.

The dermis can be split into two parts—the papillary dermis, which is thin and the upper layer, and the reticular dermis, which is thick and lower layer. 

The dermis provides accommodation to three different types of tissues

  • Collagen
  • Elastic tissue
  • Reticular fibers

  • While the dermis contains several specialized structures and cells including:

    • Sebaceous glands
    • Hair follicles
    • Endocrine glands
    • Blood vessels and other nerve endings
    • It effectively transmits the touch sensation and pressure.

    What Does The Dermis Do?

    The dermis makes up to 90% of the skin’s thickness. This middle layer of skin:

    • Has collagen and elastin: Collagen is a known protein that makes your skin cells resilient and strong.
    • Grows hair: The roots of hair follicles are attached to the dermis.
    • Keeps you in touch: Nerves that are in the dermis indicate when something is too hot, itchy, or soft to touch.
    • Makes oil: Oil glands that are present in the dermis helps in making skin soft and smooth.
    • Produces sweat: Sweat glands present in the dermis release sweat through your skin pores.
    • Supplies blood: Blood vessels present in the dermis provide it with the nutrients to keep skin healthy.

    The Subcutaneous Tissue

    Subcutaneous tissue is the innermost and deepest layer of the three skin layers. It's mostly made up of connective tissues, fat and larger blood vessels, and nerves. Similarly, the thickness of the layer depends upon where it is located like it is thickest on the buttocks, palms, and soles of your feet and the palms of the hands.

    Subcutaneous tissue also plays a vital role in regulating your body temperature and as a cushion if you ever fall or are hit with something.

    What Does The Hypodermis (Subcutaneous Tissue) Do?

    The bottom layer of skin, hypodermis, is a fatty layer. The hypodermis:

    • Has a connective tissues
    • Cushions bones and muscles 
    • Helps the blood vessels and nerves 
    • Regulates the body temperature

    Take Away

    Skin doesn’t just point the boundary between the environment and you but also serves a critical health function of protecting you from infection and exposure.

    You should take good care of your skin by applying sunscreen to stay hydrated, and also make sure that your diet should be a pack of vitamins A, C, E, and K.

    If you notice any wound, bleeding moles, or any painful cyst or teary skin you should make an appointment earliest with a trusted healthcare professional.