HISTOLOGY. 



121 



LUNGS. 



and these in turn lead into the alveolar ducts. The 

 alveolus is divided into separate chambers, all 

 communicating with one opening, called an in- 

 fundibular space. The alveolus is lined with a 

 single layer of epithelial cells. The blood vessels fol- 

 low the course of the bronchus and break up into cap- 

 illaries around the alveolus, and there the blood under- 

 goes the gaseous change. The blood changes its 

 name from venous to arterial. The lymphatics and 

 nerves are scattered all in the substance of the lung 

 tissue. The nerves are of both varieties, and they fol 

 low the course of the blood vessels. 



