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 nervous system handles the body's after-dinner activities since it governs the "rest and digest" phase of the body. It is an involuntary response that tells the body that it needs to relax and recover.
The organs involved are the following:
- Salivary glands
- Effect of PNS: secrete more saliva
- Major Nerve Supply: Glossopharyngeal nerve (CN IX)
- Esophagus
- Effect of PNS: control peristalsis
- Major Nerve Supply: Vagus nerve (CN X)
- Stomach and intestines
- Effect of PNS: Increased motility and tone; relaxation of sphincters
- Major Nerve Supply: Vagus nerve (CN X)
- Pancreas
- Effect of PNS: secretion of digestive enzymes and insulin
- Major Nerve Supply: Vagus nerve (CN X)
- Liver
- Effect of PNS: Glycogen synthesis; increased bile secretion
- Major Nerve Supply: Vagus nerve (CN X)
- Gallbladder
- Effect of PNS: contracts then release of bile into small intestine.
- Major Nerve Supply: Vagus nerve (CN X)
- Heart
- Effect of PNS: Decreased heart rate; decreased force of atrial contraction.
- Major Nerve Supply: Vagus nerve (CN X)
- Rectum
- Effect of PNS: strong peristaltic wave in the colon to push feces towards the anus
- Major Nerve Supply: Pelvic Nerve
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?
During cases of emergency, the sympathetic nervous system controls our "fight-or-flight" response. First, it detects danger or stress and sends a message to our brain to let our body react to the stress acting upon us. The heart may cause really fast to improve oxygen levels in the body, increase the production of sweat in the sudoriferous glands, and even goosebumps. Other body responses may occur, but these effects help in emergencies by improving eyesight, reflex, endurance, and strength.
References:
Parasympathetic Nervous System (PSNS): What It Is & Function. (n.d.). Cleveland Clinic. Retrieved October 6, 2022, from https://my.clevelandclinic.org/health/body/23266-parasympathetic-nervous-system-psns
Sympathetic Nervous System (SNS): What It Is & Function. (n.d.). Cleveland Clinic. Retrieved October 6, 2022, from https://my.clevelandclinic.org/health/body/23262-sympathetic-nervous-system-sns-fight-or-flight
Tortora GJ & Derrickson B. (2014). Chapter 14.8 Cranial Nerves and Chapter 15.4 Physiology of the ANS . Principles of Anatomy and Physiology. John Wiley & Sons, Inc. 14 edition. Pp 557, 596.