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.
These skin problems are often caused by an immune system reaction, signifying an allergy. Allergic skin conditions can take several forms and are due to various causes. Hives and angioedema Hives or urticaria are red, itchy, swollen areas of the skin that can range in size and appear anywhere on the body.llergic skin conditions can take several forms and are due to various causes. Hives and angioedema Hives or urticaria are red, itchy, swollen areas of the skin that can range in size and appear anywhere on the body.