Question

The center of reflex arc is

• A. Brain
• B. Spinal cord
• C. Neuron
• D. Stimulus

Answer 1

Answer: (B)

Spinal cord

Reflex arc - the process of response to a peripheral nervous stimulation that occurs involuntarily that is without conscious effort or thought and requires the involvement of a part of the central nervous system is called a reflex action. It is very rapid, automatic, stereotyped behaviour or responses in which same kind of stimulus evokes a short-lived response. The stimulus is detected by sensory receptors present n the skin. These initiate nerve impulses in the sensory or afferent neurons leading from them to the spinal cord. These impulses enter he spinal cord and initiate impulses in one or more interneurons. Interneurons initiate impulses in one or more motor or efferent neurons. The motor neurons then carry these impulses to the effectors or skeletal muscles in which response is seen. This entire pathway from sensory receptor to sensory neuron to spinal cord (having interneurons) to motor neuron to effectors is called the reflex pathway or reflex arc.

So, the correct answer is 'Spinal cord'.