From Goosebumps to Sweating, Why Do These Things Happen in the Human Body?

Also, why do we sneeze! 

The human body is a complex mechanism wherein there is an instant response to the stimuli. Ranging from goosebumps to tears to the pruning of skin, we humans experience instant changes in our bodies. But FYI, there are scientific reasons behind these responses. These responses can be for the purpose of protection of organs or as a means to perform an activity better. 

These responses are involuntary most of the times and happen in just a jiffy, under special circumstances. Why does our skin prune when exposed to immense water, why do we blink when exposed to a strong source of light and why do we get goosebumps? The human body is a masterpiece in itself which is still a big mystery for the researchers, even in the 21st Century.

But, these are everyday things which one must be aware of and the reasons behind them. Get ready to be enlightened.