Skin is the largest organ in most mammals, especially in human beings. It is the first part of us that encounters a foreign particle. Our skin has different layers and each of these layers have their own properties and functions. The skin is majorly classified into three layers being the dermis, epidermis, and hypodermis.
Epidermis vs Dermis
The main difference between Epidermis and Dermis is the position of the layer. The epidermis is the outermost exposed part of the skin, whereas the dermis lies beneath the epidermis—the difference in their composition, texture, and nature. The epidermis is the most exposed layer of the skin, and it protects the inner layers of the skin, cells, and tissues.
The epidermis is the outermost layer of the human skin. It plays the important role of protecting the delicate inner layers from the external foreign particles. The keratinocytes are the cells that form the epidermis. These cells consist of protein molecules. The epidermis is further made up of four layers.
The dermis is the layer of the skin that is present just under the epidermis. Fat, fibers, collagen, and blood vessels compose this layer of the skin. It has more flexibility and elasticity. This layer of the skin is responsible for synthesizing vitamin D when exposed to sunlight. Our body temperature is regulated and maintained by the dermis.
Comparison Table Between Epidermis and Dermis
| Parameters of Comparison | Epidermis | Dermis |
| Presence | The epidermis is the outermost layer among the three layers of the skin in an organism. | The dermis is the layer of the skin just below the epidermis. |
| Blood Vessels | Blood vessels are not present in the epidermis. | Blood vessels, which are a tiny network of blood capillaries, are present in the dermis. |
| Nerves | Nerves are not present in the epidermis. | Nerves are present in the dermis. |
| Found in | Both plants and animals have epidermis. | Only animals have dermis. |
| Absorption of Nutrients | Essential nutrients are absorbed through diffusion from the dermis. | Oxygen and essential nutrients are absorbed through the blood capillaries. |
What is Epidermis?
The epidermis is a unicellular layer that is the outermost covering of plants and animals. It acts as a barrier between the environment and the organism. The epidermis is responsible for the prevention and reduction of water loss. Gas exchange produces metabolic components and also takes in nutrients, especially in plants. In animals, too, this is the outer protective layer.
The epidermis is the home for the melanocytes, which account for the skin tone. This layer has keratin as its base. It is made up of keratinocytes and round-shaped squamous cells, which are called basal cells. The melanocytes present in the epidermis are responsible for the production of melanin. Dermatologically it is called the superficial epithelium layer.
This is a multilayered structure. It is called the basement membrane as it is responsible for the formation of dermo-epidermal junction. The keratin present in this layer has different structures due to its stages of development and maturation.
This has to lead to four more layers within the epidermis, and these are namely the Stratum basale, Stratum spinosum, Stratum granulosum, Stratum corneum. The layer is also resistant to water. It is thin in nature but has high durability. It shields you from disease-causing germs, bacteria, and viruses and also protects from harmful radiation from damaging your skin.
What is Dermis?
The dermis is also known as the sodium, is the layer between the epidermis and the tissues called the subcutaneous tissues. The dermis is further classified into two types. The dermis is connected to the epidermis with the basement membrane. It consists of collagen, which is an important component of the skin that is responsible for perfect and radiant skin.
It also consists of elastic fibers, and they account for the elasticity and firmness of the skin. This layer consists of blood vessels that are responsible for providing nourishment and also removes the gunks out from the layers. The dermis is made up of protein fibers.
This gives strength, extensibility, and elasticity. It is a thicker layer of the skin. The dermis is the depositary of the bone, and it is known as the earliest evolutionary layer of the skin. Sweat glands and oil glands are present deep under the dermis.
It is also the home of hair follicles. The dermis is further divided into two layers known as the papillary dermis, and the bottom is known as the reticular dermis. The thickness of this layer differs in organisms from one region to other—people from different regions of the world.
Main Differences Between Epidermis and Dermis
- The epidermis is the topmost layer in an organism’s skin, whereas the dermis lies underneath the epidermis.
- The epidermis does not contain blood vessels, whereas blood vessels are a part of the dermis.
- Nerves are not present in the epidermis, whereas the dermis contains the nerves and the neural networks.
- The epidermis is found in both animals and plants. The dermis is found only in the skin of animals.
- The epidermis is made up of keratinocytes, cells containing high amounts o keratin. The dermis consists of sweat glands and hair follicles.
Conclusion
The dermis and epidermis are two layers of the skin where. The outermost layer is the epidermis, and it is connected to the innermost layer called the dermis. Between the dermis and epidermis, the membrane which bridges these two layers consists of two distinct layers of connective tissues.
In this membrane, the papillary and the reticular layers are combined without any demarcation. The epidermis is the topmost layer that shields the skin, and it is also encountered a lot of foreign particles. Though the epidermis is directly exposed to sunlight, the dermis is the layer of the skin responsible for the production of Vitamin D when exposed the sunlight.
References
- https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1525-1594.2000.06334.x
- https://physoc.onlinelibrary.wiley.com/doi/abs/10.1113/jphysiol.2001.013067