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.
The pitch circle diameter (PCD) of a gear is a vital measurement when using gears. When you mesh two gears together, the teeth need to mesh to a precise distance, if too deep then the teeth will bind and wear, too shallow and you will get excessive back lash and risk damage to the teeth.