Question

Explain sensory adaptation. Give 2 examples of sensations that adapt quickly. What is an example of a slow adapting sense and why is this?

Answer 1

Sensory Adaptation: This is the process for adaptation of the different sensory stimulus. When some sensory stimulus, stimulates some specific sensory neuronal pathway of central nervous system continuously, the stimulus is become adapted to the body. This process is called sensory adaptation. In this adaptation, the receptor for the specific sensory stimulus is become desensitized to the stimulus. So that, even if the stimulus is present in same amount but the perception of the sesnory information is decreased after continuous stimulation.

Two example of quick adaptive sensations are taste and smell. i) When some stimuli is presented in the tongue for a minute the sensation and the taste of the stimuli is decreased, the receptor for the sensory signal become desensitized very fast. ii) The olfactory sensation adapts very rapidly, when some odour is exposued continuously. When some unpleasent odiur is exposed continuously, the perception of the odur is become decreased and ultimately stopped. Desensitization of the receptor is the main cause of this adaptation, this desensitization is caused by the phophorylation of the receptor by protein kinase during the interaction of receptor with the ligand (ororant molecule).

Example of slow adapting sensory sensation: Thermal(cold/hot) perception is very slow as compared to the quick adaptive sensation. If some cold or hot stimulus is exposed to the skin for a long time the perception of cold or hot sensation decreased slowly. If someone dipped his/her hand in a very cold water, he/she can perceive the cold sensation, but as the time go, the sensation is become dull and decreased and become numb. This slow decrease in the sensation is happend due to slow adaptation or desensitization of the receptor. The mechanical and thermal ssensory signal is carried from the skin tissue through C-polymodal nociceptor that is slow adapting fibre. This fibre is unmyelinated in nature. Because of this slow adapting fibre the thermal (cold) adaptation is slower than the taste or smell sensory sensation.