The chronological order of the response brought about by the nervous system is as follows.
1. Sensory receptors in the arteries detect low oxygen levels.
2. Sensory neurons generate an impulse.
3. The central nervous system relays an impulse to certain brain regions.
4. The brain sends signals through motor neurons.
5. Isabel's breathing rate increases.
The response to a stimulus is called a reflex action and the pathway traveled by the reflex action is called the reflex arch. A reflex action is an automatic involuntary response to a stimulus which minimizes any damage to the body. During conditions of low levels of oxygen in the body, the receptors detect the stimulus of low oxygen levels which could pose a threat to the individual and sensory neurons generate an impulse. It reaches the central nervous system and then the brain. In turn, brain sends signals through the motor neurons that carry a message and help in increasing the breathing rate of Isabel.
