Reflex actions are involuntary and nearly instantaneous movements in response to a stimulus, bypassing conscious brain activity to facilitate rapid response. They are crucial for survival, protecting the body from harm and maintaining homeostasis by enabling quick reactions without the need for conscious thought.
Descending neural pathways are crucial for transmitting signals from the brain to the spinal cord and peripheral nerves, enabling voluntary movement and the regulation of involuntary functions. These pathways are integral to the central nervous system's ability to control bodily actions and responses to external stimuli.