The integumentary system is the organ system that protects the body from damage, comprising the skin and its appendages (including hair, scales, and nails). The integumentary system has a variety of functions; it may serve to waterproof, cushion and protect the deeper tissues, excrete wastes, regulate temperature and is the attachment site for sensory receptors to detect pain, sensation, pressure and temperature. In humans the integumentary system additionally provides vitamin D synthesis.
The skin covers the entire outer surface of the body. Structurally, the skin consists of two layers which differ in function, histological appearance and their embryological origin. Epidermis is formed by an epithelium and is of ectodermal origin. The underlying thicker layer, the dermis, consists of connective tissue and develops from the mesoderm. Beneath the two layers we find a subcutaneous layer of loose connective tissue, the hypodermis or subcutis, which binds the skin to underlying structures. Hair, nails and sweat and sebaceous glands are of epithelial origin and collectively called the appendages of the skin.
Epidermis: This is the top layer of skin made up of epithelial cells. It does not contain blood vessels. Its main job is protection, absorption of nutrients, and homeostasis.
Dermis: The dermis is the midlayer of skin, composing of loose collective tissues such as collagen with elastin arranged in a diffusely bundled and woven pattern. These layers serve to give elasticity to the integument, not allowing stretching and conferring flexibility, while also resisting distortions, wrinkling, and sagging.
Subdermis (Hypodermis): The subdermis is the layer of tissue directly underneath the dermis. It is mainly composed of connective and adipose tissue. Its physiological functions include insulation, the storage of energy, and aiding in the anchoring of the skin.
Integumentary system functions
Functions of the integumentary system: The integumentary system has multiple roles in homeostasis. All body systems work in an interconnected manner to maintain the internal conditions essential to the function of the body. The skin has an important job of protecting the body and acts as the body’s first line of defense against infection, temperature change, and other challenges to homeostasis. Functions include:
- Protect; the body’s internal living tissues and organs, against invasion by infectious organisms, the body from dehydration, the body against abrupt changes in temperature and protect the body against sunburns
- Help excrete waste materials through perspiration
- Act as a receptor for touch, pressure, pain, heat, and cold
- Generate vitamin D through exposure to ultraviolet light
- Store water, fat, glucose, and vitamin D
- Participate in temperature regulation
Integumentary system diseases
Possible diseases and injuries to the human integumentary system include: Rash, Blister, Athlete’s foot, Infection, Sunburn, Skin cancer, Albinism, Acne, Herpes, Cold Sores…