Final answer:
The reflex pathway is swift and does not involve the brain, forming a reflex arc. Actions such as turning a page of a book involve conscious, voluntary control and the brain in directing movement. Reflexes are automatic and protective, while voluntary movements are not.
Step-by-step explanation:
The pathway of reflex reactions is different from the pathway of a voluntary nerve impulse, such as when a page of a book is turned. In a reflex action, a sensory receptor responds to a stimulus and sends a nerve impulse through a sensory nerve to the spinal cord without involving the brain. The impulse then passes to an interneuron, and from there to a motor nerve, which causes a muscle to contract. This process forms a reflex arc. An example is touching a hot stove, which results in the automatic withdrawal of the hand due to the reflex action.
In contrast, turning the page of a book involves the conscious control of movement, signaling the voluntary aspects of the somatic nervous system. In this case, the brain processes the intention to turn the page, sending signals down the spinal cord and through the motor nerves to the muscles in the hands and fingers to perform the action.
The pupillary light reflex is another reflex action where the CNS is involved, as light hitting the retina triggers a signal along the optic nerve resulting in the pupils contracting or dilating. Unlike reflex actions, which are automatic and often protective in nature, voluntary movements such as turning a page are consciously controlled and not part of the reflex arc.