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 will be handling my body’s after-dinner activities. The parasympathetic nervous system predominates in quiet “rest and digest” conditions. Its main purpose is to conserve energy to be used later and to regulate bodily functions like digestion and urination.
Organs Involved:
- Salivary Glands
- Major Nerve Supply: Glossopharyngeal Nerve (CN IX)
- The nervous system controls the saliva production which includes both the volume and type of saliva secreted.
- Stomach
- Major Nerve Supply: Vagus Nerve (CN X)
- The nervous system exerts a profound influence on all digestive processes, namely motility, ion transport associated with secretion and absorption, and gastrointestinal blood flow.
- Pancreas
- Major Nerve Supply: Vagus Nerve (CN X)
- Pancreatic functions are regulated by finely tuned inputs from the sympathetic and parasympathetic branches of the autonomic nervous system, which perform as an integrated neural circuit to adapt exocrine and endocrine secretions to constantly changes environmental and physiological conditions.
- Liver
- Major Nerve Supply: Vagus Nerve (CN X)
- The hepatic autonomic nervous system transmits information from the liver to CNS. It also regulates hepatic functions, as instructed by signals from the CNS.
- Gallbladder
- Major Nerve Supply: Vagus Nerve (CN X)
- The nervous system controls the release of bile which helps in the digestion of food.
- Small and Large Intestine
- Major Nerve Supply: Vagus Nerve (CN X)
- The enteric nervous system has a complex role in the small intestine, interacting with all cell types to modulate motility, secretion, pain perception, and inflammation. The enteric nervous system determines the movements of the gastrointestinal tract, regulates gastric acid secretion, changes in local blood flow and the gut hormones release, and interacts with the immune system in the gut.
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?
- My friend nearly collided with the bicycle, which was a very stressful situation. Because of the fight or flight response, her heart is racing, she has goosebumps, and her hands are sweaty. The fight or flight response is an automatic physiological reaction to a stressful or frightening event. Threat perception activates the sympathetic nervous system, resulting in an acute stress response that prepares the body to fight or flee. Increased heart rate and blood pressure, pale or flushed skin, sweaty hands, dilated pupils, and goosebumps can occur during the fight or flight response. You're nervous, tense, and even trembling.