A Bronchi is a passage of airway in the respiratory system that conducts air into the lungs.
The Bronchiole are tubes in the lungs that branch off from the larger bronchi that enter each lung.
Cilia:
Cilia, short eyelash like filament that are numerous on tissue cells of most animals and provides the means for locomotion of protozoans of the phylum Ciliophora.
A cilium, like a flagellum, is composed of a central core (the axoneme), which contains two central microtubules that are surrounded by an outer ring of nine pairs of microtubules.
Villi:
Villi present in the small intestine are small finger-like tissue projections that increase the surface area of the intestine and contain specialized cells that transport substances into the bloodstream.​
Alveoli:
Alveoli are the organs where the actual gaseous exchange occurs in the human respiratory system.
In the human respiratory system, the two bronchi branch extensively into bronchioles, terminal bronchioles and ultimately end in the air sacs called alveoli.
The bronchioles, their branches, and air sacs are enclosed in a double membrane called pleural membrane to form the lungs.
The lungs are the main respiratory organs.
Air passes through nostrils into bronchi, to bronchioles and into air sacs which are thin-walled sacs with a single layer of cells and heavily covered with blood capillaries.​