Changes

The '''''lung''''' has a single left lobe and four right lobes that follow the bifurcations of the bronchial tree (anterior (=apical or cranial), middle (=cardiac), median (=azygous or accessory) and posterior (=caudal)).  When the bronchus enter the lung, they divide into a major segment (at a small angle from the parent airway) and a minor segment (at a much greater angle to the parent airway).  This results in air moving at lower velocity entering the minor branch.  This is called ''monopodal branching'' and is a feature of the rat and the mouse.  A feature particular of rats is the presence of serous cells in the respiratory epithelium.

The '''''lung''''' has a single left lobe and four right lobes that follow the bifurcations of the bronchial tree (anterior (=apical or cranial), middle (=cardiac), median (=azygous or accessory) and posterior (=caudal)).  When the bronchus enter the lung, they divide into a major segment (at a small angle from the parent airway) and a minor segment (at a much greater angle to the parent airway).  This results in air moving at lower velocity entering the minor branch.  This is called ''monopodal branching'' and is a feature of the rat and the mouse.  A feature particular of rats is the presence of serous cells in the respiratory epithelium.