Oxygen is a small molecule and it's nonpolar, so it easily passes through a cell membrane. Carbon dioxide, the byproduct of cell respiration, is small enough to readily diffuse out of a cell. Small uncharged lipid molecules can pass through the lipid innards of the membrane.
Proprioception is the subconscious mechanism by which the body is able to regulate posture and movement by responding to stimuli originating in the joints, tendons, muscle, and inner ear. Proprioceptors are sensors that provide information about joint angle, muscle length, and muscle tension, which is integrated to give information about the position of the limb in space. The muscle is one type of proprioceptor that provides information about changes in muscle length. <span />
<span>Lava is an example of it. Being converted from a liquid to a solid after the eruption of a volcanoe. If thats what you mean.</span>
So it could fit perfectly.
