Human skin: composed of three layers
The skin and its attachments (nails, hair and glands) are part of the integumentary system. It is composed of three layers: epidermis, dermis and subcutaneous tissue.
The layers of the skin
The epidermis is the outermost part and the only one that is in contact with the environment. For this reason, it also has the important function of protecting the body against damage caused by external agents.
It is composed of epithelial tissue (lacking vascularization) and has five layers: basal, spiny, granular, lucid layer and corneal layer.
Their formation occurs through epidermal cells (keratinocytes, melanocytes, Langerhans cells and Merkel cells).
Yet; With the exception of the basal layer (the only layer that makes contact with the dermis), the epidermis is almost completely formed by keratinocytes.
The dermis is formed by connective tissue, which unlike epithelial tissue is richly vascularized.
In it are collagen, elastic and reticular fibers, as well as the cells that form its composition (fibroblasts, lymphocytes, mast cells…).
Still in the dermis, some glands (sweat, sebaceous), nerve endings and hair follicles are present.
Lastly comes the subcutaneous tissue, also known as hypodermis, this is made up of fat cells. It is responsible for the nutrient reserve, protection of vessels and nerves located at the deepest levels.
It is important to know that when thinking about epidermis, dermis and hypodermis, one must keep in mind that one depends on the other for the balance of this important organ that is the human skin, and also for the “perfect” functioning of our organism.
Did you know?
- Dermatology is the medical specialty that studies and deals with problems related to the integumentary system (skin).