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.
Ciliary body: Part of the eye, the ciliary body is a circular structure just behind the iris composed of the ciliary muscle and ciliary processes which attach to the lens. The ciliary processes secrete the aqueous fluid, and the ciliary muscle modifies focus by changing the shape of the lens.