Reflex Arcs

Question

Reflex arcs
A) are capable of receiving a stimulus and yielding a response.
B) are the basic structural units of the nervous system.
C) occur primarily in the cerebral cortex of the brain.
D) involve inhibitory neurons.
E) do not involve the spinal cord.

Accepted Answer

Reflex arcs are neural pathways that allow for an automatic, involuntary response to a stimulus. The stimulus is received by a sensory neuron, which then triggers a motor neuron to produce a response, without involvement or conscious control from the brain. This response can involve contraction or relaxation of muscles, secretion of glands, or changes in autonomic functions such as heart rate or breathing. Inhibitory neurons can also be involved in reflex arcs, to prevent excessive or inappropriate responses. Reflex arcs occur primarily in the spinal cord, although some may also involve the brainstem or peripheral nerves. They are not the basic structural units of the nervous system, but one of its functional components.