Question

What is the monosynaptic reflex?

Answer 1

Hint: Reflex arc is the shortest possible path which an impulse takes to travel from the receptor to the brain. It follows a specific nerve pathway. The Reflex arc is the pathway of the nerve involved in a reflex action. This consists of the Receptor organ, Afferent nerve fibers, Interneurons, Efferent nerve fibers, and Effector organs. Based on the number of synapses, the reflex is termed as Monosynaptic or Polysynaptic.

Complete answer:
Reflex action is sudden and involuntary movement in response to a stimulus. It is a protective mechanism of the body. The reflex actions include withdrawal of hand on touching a hot object, sudden blinking of the eye if any object approaches it, sneezing due to dust, etc.
The reflex action is the immediate response to the stimuli. When the receptor gets the stimulus an impulse is sent to the brain through the sensory neuron to the central nervous system. From the sensory nervous system, orders are sent through the motor nerves to the effector to give a response to the stimuli.
The structural and functional unit of the nervous system is the neurons. Now the neurons are so arranged that the axon ending of one neuron lies in the close vicinity of the dendrites of the next neuron. This junction is known as the synapse. Now, two neurons would make one synapse and would be called monosynaptic, three neurons would make two synapses and would be called disynaptic and so on.

Note:
It must be noted here that the number of synapses in almost every case would be one less than the total number of neurons involved. This is so because there can be only one junction present between two neurons.The Knee-jerk reflex or Patellar reflex is an example of a Monosynaptic reflex. It is faster than the Polysynaptic reflex. This reflex helps in proper posture and balance of the body.