The chainsaw is a highly effective and efficient tree and branch cutting power tool. It works with an engine, referred to as a power head; powering a metal chain, driven by a centrifugal clutch, with a chain moving around a groove in the guide bar at fast speeds.
adenoids. 1  one of two masses of lymphatic tissue situated on the posterior wall of the nasopharynx behind the posterior nares. During childhood these masses often swell and block the passage of air from the nasal cavity into the pharynx, preventing the child from breathing through the nose.
The adenoid was first described in 1968 by the Danish physician Meyer in his paper âAdenoid Vegetations in the Nasopharyngeal Cavity.â. Both tonsils and adenoid are part of the Waldeyer ring, which is a ring of lymphoid tissue found in the pharynx.