ABSTRACT

Exteroreceptors sense stimuli that are external to the animal; interoreceptors respond to stimuli from within the body. Stimuli include, but are not limited to electromagnetic radiation — visible, infrared (IR), ultraviolet (UV); internal mechanical inputs such as muscle stretch and tension, joint rotation, and their first and second derivatives; chemical inputs including pH, pCO

, osmotic pressure, concentration of K

,

amino acids, various odorants, pheremones, etc; sound and vibration; the Earth’s magnetic field vector; electric field intensity; external mechanical inputs such as angular velocity and acceleration and linear acceleration including the Earth’s gravity field.