Stimuli, both external and internal, are sensed with the help of sensory receptors. These sensory receptors sense the change in internal or external conditions called stimuli and send the information to the central nervous system. The sensory information is processed and interpreted in the central nervous system which in turn makes a person aware of the sensed stimuli.
However, the constant presence of the same stimulus does not trigger the firing of the action potential as it occurred during the first few encounters. This is called sensory adaption. For example, chirping of birds is apparent when a person enters the countryside but becomes less apparent after a few days due to sensory adaption of ears.
The scientist will add up the mass of the protons and mass
of the neutrons to come up with the approximate mass of atom because protons
and neutrons is what consist of the atoms. Therefore, in order to have the approximate
mass of an atom, adding the mass of protons and neutrons will give the result.
