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.
PARASYMPATHETIC NERVOUS SYSTEM - Stimulates digestion, activates metabolism, eliminates wastes, and helps the body relax.
Note: It is normal to feel tired after eating large meals because it is the parasympathetic nervous system’s response that puts us in a resting state.
Organs Involved:
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Heart: Relaxes and heart beats becomes slower as the vagus nerve stimulates as a response to eating a heavy meal.
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Lungs: regulates respiration
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Stomach: breaks down food and produces stomach acid that helps in the digestion
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Liver: involved in the production of bile
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Pancreas: Secretes enzymes
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Small intestine: also breaks down food using the bile secreted by the liver and enzymes from the pancreas; Digest fats.
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Gallbladder: stores bile from the liver and secretes it to the small intestine
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Colon/Large intestine: involved in peristalsis which is the passing of digestive process waste or stool. Removes the liquid in the stool and releases it to the rectum.
Nerve Supply:
Vagus Nerve - Connects the brain in the Gastrointestinal tract which consists of organs active during digestion
2. Your friend is driving home from work, listening to her favorite music, when suddenly a bicycle comes out of nowhere. She manages to swerve avoiding hitting the bicycle. She continued to drive home but she noticed that her heart was beating fast, she had goosebumps, and her head was sweaty. How would you explain these effects?
The sympathetic nervous system is activated when our body senses danger. Our brain triggers a release of adrenaline which makes our heartbeat faster, stimulates small muscles to pull on the roots of our hair in the skin, making it stand out, and raises our body temperature which causes us to sweat in response. It is what we call the “fight-or-flight” mode or the famous term which is the “adrenaline rush”.