what does the sympathetic nervous system do — Reading Comprehension

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"This science passage provides a clear, comprehensive overview of the sympathetic nervous system and its role in the 'fight or flight' response, tailored for a middle school audience (grades 6-8). The content aligns with life science standards (e.g., NGSS MS-LS1-8) by explaining how the body's systems work together to respond to stimuli and maintain homeostasis. Students will learn about key concepts such as involuntary bodily functions, the role of neurotransmitters like epinephrine, and the physiological changes that occur during a stress response, including increased heart rate, redirected blood flow, and glucose release. The passage connects these biological processes to relatable real-world examples, helping students understand the science behind their body's automatic reactions. This learning module is designed for self-study and includes multiple-choice questions to assess both factual recall and deeper conceptual understanding."

CONTENT PREVIEW

The human — The body's "fight or flight" response, activated by the sympathetic nervous system to prepare the body for a stressful or challenging situation.

The sympathetic nervous system is a crucial part of your body's autonomic nervous system, which controls involuntary functions like heart rate, breathing, and digestion. Its primary role is to prepare your body for sudden, demanding situations—what scientists call the "fight or flight" response. This system is activated when your brain perceives a threat, a stressful situation, or even intense physical activity. It quickly mobilizes the body's resources to help you respond to a challenge, whether that means running away from danger or performing at your best in a sports competition.

When the sympathetic nervous system is triggered, it sends signals throughout the body, causing a cascade of physiological changes. Your heart rate and breathing rate increase to pump more oxygen-rich blood to your muscles. Your blood vessels constrict in non-essential areas like the digestive system but dilate in your muscles and brain. This redirection of blood flow ensures that your muscles have the energy they need for a quick reaction, and your brain is alert and focused. Simultaneously, your pupils dilate to improve your vision, and your liver releases stored glucose into your bloodstream for an instant energy boost.

A key part of this response involves chemical messengers called neurotransmitters, such as epinephrine and norepinephrine. These chemicals are released by nerves and glands, including the adrenal glands, to amplify the "fight or flight" signals and sustain the body's heightened state. For example, the adrenal glands release a rush of epinephrine (also known as adrenaline) that can make you feel a sudden surge of energy and power. Once the threat or stress is over, the parasympathetic nervous system takes over, working to calm the body down and return it to a state of rest and balance.

Fun Fact: The "goosebumps" you get when you're cold or scared are a leftover function of the sympathetic nervous system. In our ancestors, this response would have made their hair stand on end, making them look bigger and more intimidating to predators.

What is the primary function of the sympathetic nervous system?

To calm the body downTo control voluntary muscle movementTo prepare the body for "fight or flight"To help with long-term digestion

What is an example of an involuntary function controlled by the autonomic nervous system?

Kicking a ballReading a bookBreathingWriting your name

How does the sympathetic nervous system affect heart rate and breathing?

It slows them downIt speeds them upIt has no effect on themIt makes them irregular

Which of the following is NOT a change that occurs when the sympathetic nervous system is activated?

Pupils dilateDigestion speeds upBlood flow is redirectedGlucose is released from the liver

What is the role of neurotransmitters like epinephrine in the "fight or flight" response?

To slow down muscle reactionsTo help the body restTo amplify and sustain the body's responseTo redirect blood flow to the stomach

Based on the passage, what can you infer about the parasympathetic nervous system?

It is always active at the same time as the sympathetic system.It has a calming effect on the body.It is responsible for releasing adrenaline.It only works during sleep.

What is the main idea of the reading passage?

The nervous system is made up of many different parts.The sympathetic nervous system helps the body perform everyday tasks.The "fight or flight" response is a dangerous and outdated body function.The sympathetic nervous system prepares the body for stressful situations.

A student is about to give a presentation and feels their heart racing and hands sweating. This is an example of:

The parasympathetic nervous system calming them.The sympathetic nervous system preparing them to "fight."The body conserving energy for later use.A conscious, voluntary response to stress.