heat definition In physics, a form of energy associated with the movement of atoms and molecules in any material. The higher the temperature of a material, the faster the atoms are moving, and hence the greater the amount of energy present as heat.
Cilia (singular: cilium) are microscopic, hair-like structures that extend outwardfrom the surface of manyanimal cells. These structures are important in the cell cycle and replication, and cilia play a vital part in human and animal development and in everyday life. A typical cilium is between one and ten micrometers long, and usually less than one micrometer wide.
1 A few seconds after you start smoking a cigarette, the cilia slow down. Smoking one cigarette can slow the action of your cilia for several hours. Smoking also reduces the number of cilia, so there are fewer cilia to clean your lungs.  Your lungs and airways have more mucus, and the mucus is not cleaned out well.