Answer the following questions in the discussion forum:
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.
A situation like this would mainly enlist the help of the parasympathetic division of the nervous system as it is for conserving energy and regulating body functions (Tindle & Tadi, 2021). Particularly, it may do the following:
|
Organs |
Major Nerve Supply |
Effect of Nervous System |
|
Eyes |
Oculomotor nerves |
Causes contraction of sphincter muscle of iris, resulting in pupillary constriction; causes contraction of ciliary muscles, which improves near vision |
|
Heart |
Vagus nerves |
Causes decreased heart rate and velocity of conduction through atrioventricular node |
|
Vasculature |
Vagus nerves |
Vasodilation |
|
Lungs and Bronchi |
Vagus nerves |
Bronchoconstriction; increases bronchial secretions |
|
Salivary glands |
Vagus nerves |
High-volume secretion of potassium ions, water, and amylase |
|
Stomach and intestines |
Vagus nerves |
Increases motility and relaxation of sphincters; increases gastric secretions for aiding in digestion |
|
Gallbladder |
Vagus nerves |
Stimulates contraction for release of bile |
|
Pancreas |
Vagus nerves |
Releases digestive enzymes and insulin |
|
Kidneys, bladder, ureters, and urethra |
Vagus nerves |
Stimulates peristalsis of ureters, contraction of detrusor muscle, and relaxation of internal urethral sphincter, ultimately helping in the flow and excretion of urine |
Reference:
Tindle, J., & Tadi, P. (2021). Neuroanatomy, parasympathetic nervous system. In StatPearls [Internet]. StatPearls Publishing.
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 goosebumps, and her heads were sweaty. How would you explain these effects?
These effects appear to be due to the mechanisms of the sympathetic division of the nervous system. Here, the sympathetic nervous system shines because it activates the “fight-or-flight” response. For example, the subsequent faster heart rate may be because it was increased to improve the delivery of oxygen to the parts of the body as the stress from this situation took a toll on energy use (Cleveland Clinic, n.d.). The goosebumps also stem from the involuntary flexing of tiny muscles in the skin so that hair follicles may rise. In furry animals, this kind of response is also present so that they could appear bigger and more threatening (Shmerling, 2020); thus, goosebumps may just be an evolutionary remnant of the sympathetic nervous system of ancient ancestors. Lastly, the sympathetic nervous system causes many hormones to release, including adrenaline, which is attributed to the improvement of numerous senses and the stimulation of various glands. One of these stimulated glands is the sweat glands, which are intensified during a fight-or-flight situation in order to better regulate body temperature, explaining why the friend was sweaty (Harvard Health, 2020).
References:
Cleveland Clinic. (n.d.). Sympathetic Nervous System (SNS): What It Is & Function. https://my.clevelandclinic.org/health/body/23262-sympathetic-nervous-system-sns-fight-or-flight
Harvard Health. (2020, July 6). Understanding the stress response. https://www.health.harvard.edu/staying-healthy/understanding-the-stress-response
Shmerling, R. H. (2020, October 2). Wondering about goosebumps? Of course you are. Harvard Health. https://www.health.harvard.edu/blog/wondering-about-goosebumps-of-course-you-are-2020080320688