What is Reflex arc? Why have reflex arcs evolved in animals?

The pathway of the reflex action is called Reflex arc. Reflex action is any spontaneous, involuntary and automatic response to a stimulus to protect us from harmful situations. For e.g. when a person touches a hot plate a sudden action leading to withdrawal of hand occurs in a certain manner, this path of manner determines the reflex arc.

Reflex arc have evolved in animals in order to take sudden and involuntary actions which are required in certain circumstances where emergency response is required to save body from situations which may lead to danger. lf they were not evolved,then it would take much time to respond to the stimuli as it is voluntary action thus may be not at right time and can even become dangerous.

EXPLANATION: It means that reflex action is the response which is completed by a pathway called reflex arc. For example: knee jerk etc.

These 3 steps occur to generate a response with a stimulus in a reflex arc

(i) Receive the information from environment

(ii)Receive the information from various body parts.

(Stimuli Response)

(iii) To act accordingly through muscles and glands and generate response.