The Components of the Respiratory System

The organs of the respiratory system extend from the nose to the lungs and are divided into the upper and lower respiratory tracts. The upper respiratory tract consists of the nose (nasal passage) and the pharynx (throat.) The lower respiratory tract includes the larynx (voice box) ; the trachea (windpipe), which splits into two main branches called bronchi; tiny branches of the bronchi called bronchioles; and the alveoli, located in the lungs, a pair of spongy, sac-like organs.