Question

Some Interneurons excite Somatic Motorneurons, while other Interneurons inhibit Somatic Motorneurons.

True

False

Answer 1

The given statement is TRUE

Some Interneurons excite Somatic Motorneurons, while other Interneurons inhibit Somatic Motorneurons.

Interneuron are the neurons present in the spinal cord that connect the sensory neuron with motor neuron.

In an Deep tendon Reflex like Biceps jerk, Knee jerk, Ankle jerk it consist of 2 main stretch reflexes.

They are

stretch reflex that excite the Agonist muscle

Inverse stretch reflex that Inhibit the Antagonist muscle.

This process is taking place in the spinal cord when a stimuli from the receptor is reaching the spinalcord .In the spinal cord the interneuron transmiit excitatory signal to Agonist muscle and the interneuron also send Inhibitory signal to the Antagonsit somatic muscles.

For Example

IN knee Jerk reflex(Normal response is knee extension 5 to 8 cm forward movement)

When the pattellar tendon is mechanically stimulated ------> sensory nerve ---->spinal cord ------> inter neuron

Interneuron will send EXCITATORY signal to Somatic motor nerve supplying the Quadriceps muscle (agonist) and the response is contraction of the Quadriceps causes extension of the knee

interneuron send INHIBITORY signal to somatic motor neuron supplying the Hamstrings Muscle (Antagonist) and the response is relaxation of the Hamstrings muscle .

Other example is Biceps Jerk reflex

Here the interneuron send EXCITATORY signal to the Somatic motor nerve supplying the Biceps brachii and cause contraction of the biceps resulting flexion of Forearm.

At the same time the inetrneuron send INHIBITORY signal to motor nerve supplying the Triceps muscle (antagonist) and the result is relaxation of the triceps