HLTC22H3 Chapter 5: Chapter 5
Document Summary
Basic anatomy and physiology y the skin, or integumentary system, has several major functions. It is the front line of defense against harmful environmental influences and is an important part of our immunological and endocrine systems. The skin is critical in temperature maintenance and, in general, aids in homeostasis. Sensory nerves in the skin allow us to monitor the environment but also warn us of danger through pain. Beneath the epidermis and dermis is a layer of subcutaneous fat. As young cells, keratinocytes are found deep in the epidermis. They slowly move to the surface of the epidermis as they age, a process that takes about 30 days. If the skin is injured, the keratinocytes will reproduce and turn over at a more rapid rate, allowing the damage to be repaired. Exposure to the sun results in an increase in melanin production by these cells, which helps to protect the skin from damage.