1. You have been to an ‘eat all you can’ buffet and have consumed large amounts of food. After returning home, you recline on the couch to watch television. Which division of the nervous system will be handling your body’s after-dinner activities? List several organs involved, the major nerve supply to each organ, and the effects of the nervous system on their functions.
The parasympathetic division of the nervous system is in charge of controlling the body's post-meal activity. Below are the organs involved in the activity:
- Salivary glands
Major nerve supply: Facial nerve (CN VIII)
Effects: produce saliva—controlled by the autonomic nervous system—that helps lubricate and break down food
- Esophagus
Major nerve supply: Vagus nerve (CN X)
Effects: stretching from food or liquid stimulates the smooth muscles that make up the walls of esophagus, and allow transport of materials to the stomach
- Lungs
Major nerve supply: Vagus nerve (CN X)
Effects: the autonomic nervous system controls the breathing rate
- Heart
Major nerve supply: Vagus nerve (CN X)
Effects: the autonomic nervous system controls heart rate and blood flow
- Pancreas
Major nerve supply: Vagus nerve (CN X)
Effects: the autonomic nerve system influences glucose metabolism by controlling the endocrine pancreas' hormone output.
- Liver
Major nerve supply: Vagus nerve (CN X)
Effects: the autonomic nerve system regulates chemical levels in the blood
- Stomach
Major nerve supply: Vagus nerve (CN X)
Effects: the enteric nervous system contributes to overall gastrointestinal motility, nutrient handling, gastric acid secretion, and other functions within the GI tract
- Large and small intestines
Major nerve supply: Vagus nerve (CN X)
Effects: the enteric nervous systems aid in secretion and motility to achieve adequate nutrient absorption; modulate motility, pain perception, and inflammation
- Gallbladder
Major nerve supply: Vagus nerve (CN X)
Effects: the parasympathetic system stimulates the contraction of the muscle wall in the gallbladder that releases and stores bile which help in digestion
- Urinary bladder
Major nerve supply: Vagus nerve (CN X)
Effects: the autonomic nervous systems regulates the function of urinary bladder that controls its contraction and passage of urine
- Rectum
Major nerve supply: Pelvic nerve
Effects: the autonomic nervous system regulates the function of rectum which stores solid wastes until defecation occurs.
2. Your friend is driving home from work, listening to her favorite music, when suddenly a bicycle came out of nowhere. She manages to swerve avoiding hitting the bicycle. She continued to drive home but she noticed that her heart is beating fast, she had goose bumps, and her heads were sweaty. How would you explain these effects?
The sympathetic nervous system, also referred to as the body's fight-or-flight reaction, is associated to this kind of experience. The sudden appearance of the bicycle causes my friend to react immediately by swerving to avoid hitting the bicycle; which increases her heart rate, goosebumps, and perspiration as a result of fear. This motion demonstrates the body's fight-or-flight reaction in such an unanticipated circumstance.