Have you ever tried to touch the ‘touch me not‘ plant(Mimosa pudica)?


You must have noticed that it shrinks down.

Since it reacted because you touched. Then ‘your touch‘ can be called stimulus. And the plural form is stimuli.

Actually it’s not for only plants it’s for all the living beings.

Even while taking an example of a human being. Just suppose of yourself. If someone touches you, you automatically sense it or not? Ya! of course, you sense it.

Have you ever wondered, how do you get to know or feel someone touched you?

Of course! its not by seeing. Just don’t think of a silly answer. You even get to know someone touched you even when you fall asleep.

If you touch any hot plate accidentally, you just remove your hand from it. The response you generated is because of the hot plate.

Basically that’s happening because of the concept of stimuli.

That hot plate is the stimulus.


“This word Stimuli is repeating every time and I just don’t know what this word means?” that must be what your brain is yelling now.

Actually this yelling is also due to stimulus.

And here stimulus is the word ‘stimulus.’

Okay, let me tell you.

A type of signal is sent to your brain when any type of action takes place internally or externally with your body and in return, your brain reverts back a sensation and then you feel it or sense it (of course because of sensory organs), because of which it happens that is what we call stimulus.


And the plural form is stimuli.

All the reflex actions are due to stimuli.

No, that is not over yet. This was just the overview I created that what basically stimulus is. Now we’ll discuss the topic in detail.

We’ll study the topic in the following blueprint.

  • Definition of Stimulus
  • Types of the stimulus.
  • Cause of Stimulus
  • Examples of the stimulus.
  • Conclusion

So, now take a deep breath, and let’s go with the flow.


A thing or event that evokes a specific functional reaction in an organ or tissue.

In other words, a thing which arouses or excites any part of a living being to take any action.


Types of Stimulus

There are basically two types of stimulus-

Internal Stimulus

This is the cause of action due to the change in the conditions taken place inside the body of living being.

External Stimulus

This is the cause of action due to the change in the conditions taken place outside the body of living beings.

Cause of Stimulus

Anything could be a cause of stimulus which is able to arouse action.

E.g; An alarm clock, money, an opposite-sex anything which is able to excite any type of action.

Examples of Stimulus

  • Homeostatic imbalances
  • Blood pressure
  • Touch and pain
  • Vision
  • Smell
  • Taste
  • Sound
  • Equilibrium
  • Cellular response
  • Nervous-system response
  • Muscular-system response
  • Endocrine-system response



Hope till now after so much explanation you have understood what the stimuli meant for? However, if you haven’t, just remember in simple words anything or everything you do is because of stimuli. In other words, any action you perform then the thing which influences you to do that is stimuli.


Anything which causes an organism to react or respond is the stimulus.

Incase, further you have any type of doubt then just put it in the comment section.I’ll happy to answer it.


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Prashant Raj Tiwari

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