Reflex Action: Definition and Classification - QS Study
QS Study

Reflex Action

Involuntary motor response due to any sensory stimulus is called the reflex action. When a person accidentally touches a hot object, they automatically jerk their hand away without thinking. A reflex does not require any thought input. The function or action occurs immediately, without the involvement of the will or consciousness.

Classification of reflex

(A) General Classification:

Unconditioned reflex: Inborn and Unchanged.

  • Superficial reflex: Corneal, conjunctival, abdominal, cremasteric and planter reflex.
  • Deep reflex: knee jerk, Biceps jerk, Triceps jerk, supinator jerk.

Conditioned reflex: Acquired.

Fig: Reflex Action

(B) According to the number of synapses

  1. Monosynaptic reflex: eg, stretch reflex,
  2. Polysynaptic reflex: eg, withdrew rearm.

Some reflexes that move skeletal muscles are called: flexor, extensor, locomotor, and statokinetic. Some common examples of reflex actions are:

  • The knee-jerk reflex, when tendon of the kneecap is tapped, it stimulates the stretch receptors in the tendon, and leg is unwillingly and temporarily straightened.
  • The quick closing of the eyelids or blinking reflex, when an object approaches the eye.
  • Sneezing reflex in response to irritation of the lining of the nose.