Respiratory system

Abstract

The pulmonary system consists of the lungs, airways, pulmonary and bronchial circulation, and chest wall. The lungs consist of lobes, three in the right (upper, middle, and lower) and two in the left lung (upper and lower). Each lobe is again divided into segments and lobules (Fig. 13.1). The airway system consists of upper airways (nasopharynx and oropharynx) and lower airways (trachea, bronchi, bronchioles, and alveolar ducts) connected by the larynx (Fig. 13.2).