Changing levels of certain substances in the blood, such as sodium, can cause confusion. Increased heart rate...heart palpitations, which feel like your heart is racing or throbbing. To make up for the loss in pumping capacity, the heart beats faster.
The pitch plane of a pair of gears is the plane perpendicular to the axial plane and tangent to the pitch surfaces. A pitch plane in an individual gear may be any plane tangent to its pitch surface.
Metric gears are defined by module, which designates the center-to-center distance between successive teeth. This criterion of gear selection is used in countries which have adopted the metric system and is intended to standardize gear selection. To define a gear's module, the pitch diameter (the teeth bearing circumference) of the gear is divided--in millimeters--by the number of teeth.