Our body responds to changes in the environment without even thinking of it. We term this reflex action. Here the peripheral nervous system (spinal cord) of the brain responds to changes and do the action with minimal time.
Agarbatti or incense stick on burning produces fragrance. These fragrances reach to olfactory bulb through the nose.The olfactory bulb is a chemosensory organ. It detects the presence of chemicals present in the air
Every part of the brain does some specific functions. For example, frontal part of the brain is our think centre, spinal cord and medulla oblongata regulates our heart rate and breathing pattern.
A synapse is the junction between the two neurons. Consider this as a joint in an electric wire junction. In an electrical wire, electricity passes two wire through the joint by electron transfer.