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.
Hives are also known as urticaria, welts, wheals, or nettle rash. It is a red, raised, itchy skin rash that is sometimes triggered by something that produces an allergic reaction-an allergen. When there is an allergic reaction the body releases a protein called histamine.cute urticaria or Acute hives. When symptoms last less than 6 weeks it is called acute urticaria. This is by far the most common type. 25% of people with acute urticaria also have angioedema-swelling in the deeper layers of skin.