The lungs are the brownish lobes to the right and left of the heart. Entering the lungs on either side from the Trachea are the Bronchi. They are supported, as is the Trachea, by incomplete cartilage rings. Cut through a lung and trace the divisions and subdivisions of the bronchi. Too small to see are the small end branches, the Infundibula, which are lined with Alveolar sacs.
Different animals vary in the number of lobes to each lung.
The cat and rat have 4 right lobes, humans have 3. The cat has 3 left lobes, rats have one and humans have 2. Trace the Trachea anteriorly. The rings supporting it are incomplete. Trace the trachea anteriorly to the Larynx, or Voice Box.