Autonomic nervous system (ANS) and physiologic markers of emotion | MCAT | Khan Academy

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Physiologic changes like increased heart rate and quicker breathing are controlled by the autonomic nervous system, with the sympathetic branch triggering fight or flight responses and the parasympathetic branch promoting rest and digest activities. Understanding the functions of both branches is key to comprehending the body's responses to emotional stimuli and adapting to different situations effectively.

Insights

  • Physiologic changes like increased heart rate and quicker breathing are controlled by the autonomic nervous system, with the sympathetic branch triggering fight or flight responses, while the parasympathetic branch induces a rest and digest state.
  • The autonomic nervous system, comprising the sympathetic and parasympathetic branches, impacts key organs differently based on whether the body is in a state of fear or relaxation, highlighting the intricate balance between preparation for action and energy conservation in response to emotional stimuli.

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Recent questions

  • What controls heart rate and breathing?

    The autonomic nervous system regulates heart rate and breathing.

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Summary

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Autonomic Nervous System: Fear vs. Relaxation

  • Physiologic changes like increased heart rate and quicker breathing occur automatically due to the autonomic nervous system, specifically the sympathetic and parasympathetic branches.
  • The sympathetic nervous system, known as the fight or flight response, causes changes in organs like dilated pupils, decreased salivation, increased respiratory rate, and heart rate, as well as the release of adrenaline from the adrenal glands.
  • The parasympathetic nervous system, associated with rest and digest, causes opposite effects like pupil constriction, increased salivation, decreased respiratory and heart rate, and increased glucose storage, as well as decreased adrenaline release.
  • Both branches of the autonomic nervous system affect organs like the eyes, salivary glands, lungs, heart, liver, adrenal glands, and gastrointestinal tract in different ways based on the body's state of fear or relaxation.
  • The sympathetic nervous system prepares the body for action by increasing energy availability and decreasing digestion, while the parasympathetic nervous system focuses on nutrient extraction and energy storage through increased digestion and glucose storage.
  • Understanding the functions of the autonomic nervous system is crucial in comprehending how the body responds to emotional stimuli and prepares for different situations.
  • The sympathetic and parasympathetic nervous systems play vital roles in regulating bodily functions and responses, ensuring the body can adapt to various emotional and physical demands effectively.
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