Science Articles

WHAT IS REFLEX ACTION AND REFLEX ARC?

Reflex action is when the stimulus is followed by an immediate action. Reflex actions are taken without your information. That means that we don’t think before the reaction comes out. Reaction or the action is immediate, quick and without thinking.

Reflex action is when the stimulus is followed by an immediate action. Reflex actions are taken without your information. That means that we don’t think before the reaction comes out. Reaction or the action is immediate, quick and without thinking.

Reflex action is used for describing an action that does not involve consciousness, is inborn activity of central nervous system, in which any stimulus produces an immediate response of muscle or gland.

Reflex is involuntary and the sudden response to stimuli. Most of the common reflexes are in response to the well trained, assembled up knowledge of caution. Reflex action could be anything- even, immediately removing your hand when it touches something extremely hot or cold.

EXAMPLES OF REFLEX ACTION

Reflex actions can be understood by the following examples-

  • Moving away your hand after touching a hot object. This is a reflex action and is immediate. You don’t think twice before removing your hand from the hot object. You feel the burn and immediately the action is taken.
  • The act of breathing. You don’t breathe and think. Breathing comes naturally. Controlling the breathing would need a lot of effort. Otherwise, it’s involuntary and done unconsciously.
  • When a doctor taps his patient’s knee with a small mallet, the immediate reflex action is the jerking of the knee upwards. The knee jerk reaction is very natural. The patient doesn’t think before doing it.
  • Reflexes can be like lifting up your foot automatically as soon as something gets stuck on your foot. We don’t think whether or not we should lift up our foot. It’s quick, sudden and immediate.
  • When something gets on in our eyes, we blink furiously to try and remove it. This is a reflex action. We don’t blink out of our own will. It just happens.

REFLEX ARC

Afferent neuron (receptor) and efferent neuron (effector or excitor) are the two neurons that dominate the pathway. The events that take place during this-

  • Receptor detects the stimulus or the sudden change in the environment. Stimulus is received from sensory organs.
  • Signal is sent to relay neuron by sensory neuron.
  • Motor neuron receives the signal from the relay neuron.
  • Motor neuron further sends the signal to the effector.
  • There is an instantaneous response produced by the effector.

Reflex actions do not need the involvement of the brain hence they are instantaneous in nature.