1. Under the rest and digest functioning, the Parasympathetic Nervous System under the Autonomic Nervous System controls the following organs to stimulate the body’s after-dinner activities. The nerves carry signals from the Nervous System, going to these organs, and therefore, stimulating a bodily response:
Stomach
- Major Nerve Supply: Vagus Nerve
- Effects of Nervous System on their function: stimulates the start of digestion after the “rest and digest” signal
Intestines
- Major Nerve Supply: Vagus and Pelvic Nerves
- Effects of Nervous System on their function: stimulate digestive activities and regulate propulsive colonic motility
Bladder
- Major Nerve Supply: Pelvic Nerves
- Effects of Nervous System on their function: contracts bladder
2. From peacefully driving a car through the Parasympathetic Nervous System, the sudden interruption of the bicycle causes my friend to switch to Sympathetic Nervous System, activating her fight or flight response that releases hormones for physiological reaction. The sudden activation of the Sympathetic Nervous System causes her to respond quickly and avoid causing an accident. After that activation, the Parasympathetic Nervous System acts again on her body, releasing hormones that signal her organs to calm down. However, the Sympathetic Nervous System hormones are still lingering on her body, which is simultaneously inhibited by the hormone released by the Parasympathetic Nervous System; that is why there is a continuous appearance of physiological effects while switching back again to the Parasympathetic Nervous System. The response of both systems keeps her body balanced and maintains homeostasis.