When tiny amounts of hormones are cast into your bloodstream, they can evoke profound effects on organs far from the gland that secreted them. The endocrine glands that produce hormones -- the pituitary, pineal, thyroid, thymus, parathyroids, adrenals, pancreas and gonads -- are scattered throughout your body. Some hormones, such as estrogen, originate from several glands and tissues.
Psychrometer An instrument used to measure the water vapor content of the air. It consists of two thermometers (dry bulb and wet bulb). After whirling the instrument, the dew point and relative humidity can be obtained with the aid of tables.
A potentiometer is a manually adjustable electrical resistor that uses three terminals. In many electrical devices, potentiometers are what establish the levels of output. For example, in a loudspeaker, a potentiometer is used to adjust the volume. In a television set, computer monitor or light dimmer, it can be used to control the brightness of the screen or light bulb.