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 division of the nervous system that will be handling your body’s after-dinner activities is the parasympathetic nervous system. This division regulates the activity of the viceral organs, smooth and cardiac muscles, and glands when your body is relaxed.
|
Organ |
Major Nerve Supply |
Effects of Nervous System on their Functions |
|
Salivary glands |
Facial (VII) Nerve and Glossopharyngeal (IX) |
Mucus secretion |
|
Stomach |
Vagus Nerve (X) |
Increased mobility and tone and the relaxation of sphincters |
|
Heart |
Decreased heart rate; decreased force of atrial contraction |
|
|
Lungs |
Contraction of bronchial walls |
|
|
Bladder |
Contraction of walls; relaxation of sphincter |
|
|
Liver |
Glycogen synthesis; increased bile secretion |
|
|
Pancreas |
Secretion of digestive enzyme and insulin |
|
|
Small and large intestine |
Increased mobility and tone and the relaxation of sphincters |
|
|
Gall bladder |
Release of bile into small intestine |
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?
Due to the emotional stress caused by the bicycle that startled her while driving home, her sympathetic division is activated. This is called the fight-or-flight response wherein the adrenal glands release hormones that activates the sympathetic division of the body. As a result, it reduces body functions that favor storage energy; thus, the increased heart rate, excessive sweat production, and contraction of arrector pili muscles.