Question

What is meant by a reflex arc in the nervous system?

• A. An inherited behaviour pattern that functions through a certain neural pathway
• B. A functional unit consisting of a receptor, neural pathway, and an effector
• C. Peripheral nerves, spinal cords and brain
• D. A homeostatic system of sensory nerves, synapses and motor nerves

Answer 1

The correct option is B A functional unit consisting of a receptor, neural pathway, and an effector

A reflex arc is a neural pathway that controls a reflex. Most sensory neurons do not pass directly into the brain, but synapse in the spinal cord. This allows for faster reflex actions to occur by activating spinal motor neurons without the delay of routing signals through the brain. nerve signals travel along the following pathway:

1. Somatic receptors in the skin, muscles and tendons

2. Afferent nerve fibers carry signals from the somatic receptors to the posterior horn of the spinal cord or to the brainstem

3. An integrating center, the point at which the neurons that compose the gray matter of the spinal cord or brainstem synapse

4. Efferent nerve fibers carry motor nerve signals from the anterior horn to the muscles

5. Effector muscle innervated by the efferent nerve fiber carries out the response.