By Regina Bailey. Definition: Homeostasis is the ability to maintain a constant internal environment in response to environmental changes. It is a unifying principle of biology. The nervous and endocrine systems control homeostasis in the body through feedback mechanisms involving various organs and organ systems.
Urticaria is the medical term for a type of allergic rash. Hives are the most common type of urticaria. Hives are itchy, pink to light red, raised blotches that are usually one-quarter to one-half inch in size.Hives can occur on any part of the body.ives are the most common type of urticaria. Hives are itchy, pink to light red, raised blotches that are usually one-quarter to one-half inch in size. Hives can occur on any part of the body.
Urticaria, also known as hives, is an outbreak of swollen, pale red bumps or plaques (wheals) on the skin that appear suddenly -- either as a result of the body's reaction to certain allergens, or for unknown reasons. Hives usually cause itching, but may also burn or sting.cute urticaria: Hives lasting less than six weeks. The most common causes are certain foods, medications, or infections. Insect bites and internal disease may also be responsible. The most common foods that cause hives are nuts, chocolate, fish, tomatoes, eggs, fresh berries, and milk.