Perforating Disorders. Perforating Disorders. Classically, a group of disorders in which there is transepidermal elimination (âperforationâ) of components of the dermis, in particular collagen and/or elastic fibers (Table 79.1).
Nitrogen is a chemical element with symbol N and atomic number 7. It is the lightest pnictogen and at room temperature, it is a transparent, odorless diatomic gas. Nitrogen is a common element in the universe, estimated at about seventh in total abundance in the Milky Way and the Solar System.t is the lightest pnictogen and at room temperature, it is a transparent, odorless diatomic gas. Nitrogen is a common element in the universe, estimated at about seventh in total abundance in the Milky Way and the Solar System.
Further information: Urea Â§ Physiology, and Urea cycle. The nitrogen compounds through which excess nitrogen is eliminated from organisms are called nitrogenous wastes (/naÉªËtrÉdÊáµ»nÉs/) or nitrogen wastes. They are ammonia, urea, uric acid, and creatinine. All of these substances are produced from protein metabolism.