Question 5
What is the role of the brain in reflex action?
1. Reflex actions are sudden involuntary responses which do not involve thinking.
2. For example, when we touch a hot object, we withdraw our hand immediately without thinking. The sensory nerves that detect the heat from the receptors in the skin are connected to the nerves that move the muscles of the hand. This complete pathway of detecting the signal from the nerves (input through afferent nerves) and responding to it quickly (output through efferent nerves) is known as the reflex arc. Reflex arcs are formed in the spinal cord but the information is still sent to the brain.
3.The three major parts of the brain are the fore-brain, midbrain, and the hind-brain. The forebrain is the main thinking part of the brain. It has regions which receive sensory impulses from various receptors. Separate areas of the fore brain are specialised for hearing, smell, sight etc. There are separate areas of association where this sensory information is interpreted by putting it together with information received from other receptors as well as with information that is already stored in the brain. Based on all this a decision is made about how to respond and the information is passed on to the motor areas which control the movement of voluntary muscles, for example, our leg muscles.