The Integumentary System
The integumentary system, one of the most significant systems in the body, is crucial. The skin, hair, nails, and exocrine glands are the main components of the integumentary system. It is important to remember that the skin is the largest organ in the entire human body, despite only being a few millimeters thick. The integumentary system's main job is to keep the body safe (Rizzo, 2015). The skin creates a barrier that shields the body from harmful substances including pollutants, bugs, and ultraviolet rays as well as from physical harm. Furthermore, the nails and hail extend from the skin and serve to act as the first line of defense against the elements, sensing changes in the environment, removal of waste, and regulation of body temperature.
Anatomy and Physiology
Structure of the Skin
The skin is made up of two types of tissue, the epidermis on the outside and the underlying dermis (Rizzo, 2015).
Epidermis
The epidermis is the outermost layer of the skin. It rests upon and protects the thicker dermis. It is avascular, and the cells in the dermis receive nutrients through diffusion from the dermis. It has a variety of specialized cells, and most of it is made up of keratinocytes (Marieb & Hoehn, 2007). It is also composed of melanocytes which protect the skin from UV light. Langerhans cells detect and fight pathogens while Merkel cells sense touch.
Dermis
It is the deep layer locater under the epidermis and is composed of irregular connective tissue, nervous tissue, blood vessels and blood. It is thicker and gives the skin its strength and elasticity (Marieb & Hoehn, 2007). There are two distinct regions of the dermis, the papillary layer, and reticular layer. The papillary layer contains the dermal papillae which have nerves and blood vessels to supply nutrients to the epidermis. The reticular layer is dense and contains dense connective tissue to give the skin its elasticity and strength.
Hypodermis
Attaches the skin to structures below it, it is an insulator and also a shock absorber. It is also known as the subcutaneous layer.
Hair
This element of the integumentary system is found in almost all regions of the skin. It grows on hair follicles that are part of the epidermis. They help regulate body temperature in addition to protecting the body surface including the eyes.
Nails
Nails are found on the edges of fingers and toes. They offer protection to the phalanges protecting them from trauma. They grow from epidermal cells.
Glands
Glands also form an integral part of the integumentary system and are found in various regions of the skin. They produce secretions that are essential for numerous physiological functions (Rizzo, 2015). They include; sebaceous glands, apocrine glands, and merocrine glands.
References
Marieb, E. N., & Hoehn, K. (2007). Human anatomy & physiology. Pearson Education.
Rizzo, D. C. (2015). Fundamentals of anatomy and physiology. Cengage Learning.
