The integumentary system consists of the skin, which is made up of epidermis and dermis, along with a layer below the skin called as hypodermis. These structures protect the body and play an important role in thermoregulation, vitamin D production, detection of stimuli, and nutrient storage. Glands in the skin perform a variety of functions. Some glands produce sweat to cool down the body. Others produce an oily substance called sebum that lubricates and protects hair and skin. Other glands perform more specialized functions. Structures such as hairs and nails are also part of the integumentary system and play important roles in maintaining internal body temperature and protection.
At A Glance
- The functions of the integumentary system include maintaining internal body temperature, protection, vitamin D production, detection of stimuli, and nutrient storage.
- The epidermis is the top layer of skin, while the dermis, which is the thickest layer, and the hypodermis, which is the basement layer, are found underneath.
- The epidermis is composed of at most five layers of cells, with each layer contributing to the overall functions of the skin.
- The dermis is composed of connective tissue that contains glands, nerves, blood vessels, hair follicles, and sensory receptors and can be further classified into a papillary layer and a reticular layer.
- The hypodermis separates the dermis and the muscles and is composed of areolar and adipose tissue.
Skin color is determined by pigments in the skin and blood and is a factor of genetic and environmental influences.
Three types of hair grow out of follicles embedded in the dermis, each differing by color, texture, and function.
Fingernails and toenails are derived from the stratum corneum. They serve a protective function and can be used as tools.
- Specialized glands in the skin include eccrine, apocrine, ceruminous, sebaceous, and mammary.
- The skin contains stem cells that allow it to repair itself in four major steps: hemostasis, inflammation, reepithelialization, and remodeling.
- When large surfaces are injured following a burn, the body is at high risk because of infection.