Sensing and Reacting

We have 5 senses to detect changes in the environment around us. These changes are known as and we have in different organs to detect them:

Sense	Stimuli	Organ with Receptors
Sight (Vision)		Eye
Hearing (Audition)	Sound
(Olfaction)	Chemical	Nose
Taste (Gustation)	Chemical
(Mechanoreception)	Pressure	Skin

We can also detect changes inside our body for example (Thermoception) and level.

Information from the is sent to the brain via neurons (nerve cells). Then commands are sent to via neurons. The effectors may either be or .

will contract, moving the body. release chemical into the blood called , which affect other organs.