thanks

The lining of the respiratory system is mainly made with pseudostratified columnar epithelium. Goblet cells and cilia are  present

What are the roles of cilia and goblet cells in the respiratory tract?  How does smoking affect their functions?
Here are histology slides for you to review the respiratory system:

http://www.meddean.luc.edu/lumen/meded/Histo/frames/h_fram15.html
http://www.siumed.edu/~dking2/crr/rsguide.htm#epith