Question

The sympathetic division of the autonomic system does not cause a. the liver to release glycogen. b. dilation of bronchioles. c. the gastrointestinal tract to digest food. d. an increase in the heart rate.

Short answer

The correct answer is (c) the gastrointestinal tract to digest food, as this is not a function of the sympathetic division of the autonomic nervous system. The sympathetic nervous system, also known as the "fight or flight" response, inhibits digestion during stressful situations to focus on other vital processes.

Step-by-step solution

Understand the sympathetic division of the autonomic nervous system

The sympathetic division of the autonomic nervous system, also known as the "fight or flight" system, is responsible for preparing the body for stressful or emergency situations. Its primary functions include increasing heart rate, dilating pupils, increasing respiratory rate, and releasing glucose into the bloodstream.

Evaluate each option

a. the liver to release glycogen: The sympathetic nervous system promotes the release of glucose into the bloodstream by stimulating the liver to convert glycogen to glucose. So, this option is a function of the sympathetic division. b. dilation of bronchioles: Dilation of the bronchioles is another function of the sympathetic nervous system. It helps increase the amount of oxygen that can exchange with the blood, which is necessary during stressful situations. So, this option is also a function of the sympathetic division. c. the gastrointestinal tract to digest food: The sympathetic nervous system is responsible for inhibiting digestion during a "fight or flight" response. When the body is in a stress response, its focus shifts away from digestion and towards other vital processes. So, this option is *not* a function of the sympathetic division. d. an increase in the heart rate: The sympathetic nervous system is responsible for increasing heart rate to ensure the body has enough blood supply during a stress response. So, this option is a function of the sympathetic division.

Identify the correct answer

Since option c (the gastrointestinal tract to digest food) is the only option that is not a function of the sympathetic division of the autonomic nervous system, it is the correct answer.

Key concepts

Sympathetic Division

The autonomic nervous system controls involuntary actions in the body, like heart rate and digestion. It has two main parts: the sympathetic and parasympathetic divisions. The sympathetic division is often called the "fight or flight" system. Its main role is to prepare the body for stressful situations.

When the sympathetic division is activated, it triggers a series of bodily responses. These include:

• Increasing heart rate: This ensures that more oxygen is pumped to vital organs.
• Dilating bronchioles: Allowing more air into the lungs for a greater oxygen supply.
• Releasing glucose: The liver converts glycogen to glucose and releases it into the bloodstream for energy.

The sympathetic division is crucial for survival because it equips the body to handle emergencies and stress effectively. However, it's important to balance this system with the parasympathetic division, which calms the body down after the threat has passed.

Fight or Flight Response

The term "fight or flight response" describes how the body reacts in a split second to perceived threats. This physiological response is automatic and quick.

When a threat is sensed, the brain sends signals through the autonomic nervous system. The sympathetic division kicks in, producing hormones like adrenaline. This hormone surge leads to rapid reactions such as:

• Increased heart rate and blood pressure: Preparing the muscles for quick action.
• Increased respiration: Providing more oxygen to critical parts like muscles and brain.
• Dilation of pupils: Improving vision, especially in dim light or at a distance.

However, while this response is vital in dangerous situations, if triggered too often due to stress, it can lead to health problems. Hence, understanding the fight or flight response helps manage stress better.

Physiological Effects

The body undergoes numerous physiological changes during a sympathetic response. These changes optimize the body for swift action necessary to confront or flee from danger.

Key physiological effects include:

• Elevated heart rate: Ensures that blood reaches critical muscle groups efficiently.
• Inhibited digestion: Blood is redirected from the digestive system to the brain and muscles, prioritizing energy usage elsewhere.
• Release of glucose and fats: Provides immediate energy to the body.

While these changes are beneficial in short bursts, prolonged activation can be harmful, leading to fatigue, insomnia, and anxiety. Healthy lifestyle practices, including exercise and relaxation techniques, can help harness these physiological effects positively.