Problem 1 - Campbell Biology

Question

Activation of the parasympathetic branch of the autonomic nervous system \begin{equation} \begin{array}{l}{\text { (A) increases heart rate. }} \\ {\text { (B) enhances digestion. }} \\ {\text { (C) triggers release of epinephrine. }} \\\ {\text { (D) causes conversion of glycogen to glucose. }}\end{array} \end{equation}

Step-by-Step Solution

Answer

Option (B) enhances digestion.

Step 1 - Understand the Parasympathetic Nervous System

The parasympathetic branch of the autonomic nervous system conserves energy and promotes 'rest-and-digest' functions. It typically lowers heart rate, enhances digestion, and promotes relaxation responses in the body.

Step 2 - Analyze Option (A)

Option (A) states that activation of the parasympathetic branch increases heart rate. This is incorrect because the parasympathetic response actually decreases heart rate.

Step 3 - Analyze Option (B)

Option (B) states that activation of the parasympathetic branch enhances digestion. This is correct because the parasympathetic system stimulates digestive activity.

Step 4 - Analyze Option (C)

Option (C) states that activation of the parasympathetic branch triggers the release of epinephrine. This is incorrect because epinephrine release is associated with the sympathetic branch.

Step 5 - Analyze Option (D)

Option (D) states that activation of the parasympathetic branch causes the conversion of glycogen to glucose. This is incorrect because this process is part of the 'fight-or-flight' response, mediated by the sympathetic branch.

Step 6 - Determine the Correct Answer

Based on the analysis, the correct answer is Option (B) as it accurately reflects the role of the parasympathetic branch in enhancing digestion.

Key Concepts

autonomic nervous system

The autonomic nervous system (ANS) controls involuntary bodily functions like heart rate, digestion, and respiratory rate. It functions without conscious effort and is divided into two main branches: the sympathetic and the parasympathetic nervous systems.
The sympathetic branch activates the body's 'fight-or-flight' response, preparing it for stressful situations. It increases heart rate, dilates pupils, and inhibits digestion during emergencies.
Conversely, the parasympathetic branch conserves energy by promoting 'rest-and-digest' activities. It slows the heart rate, stimulates digestive processes, and encourages relaxation.
Understanding the ANS's dual nature is crucial for grasping how our bodies maintain internal balance and respond to external stimuli.

heart rate regulation

Heart rate regulation is a primary function of the autonomic nervous system. The parasympathetic nervous system plays a vital role in keeping heart rates low during calm and restful states.
When the parasympathetic branch is activated, it sends signals via the vagus nerve to decrease the heart's activity. This slows down the heart rate and conserves energy.
On the other hand, the sympathetic nervous system increases heart rate in response to stress or danger. Understanding this regulation helps in comprehending how the body adjusts its cardiovascular functions during varying physical and emotional states.

digestion enhancement

Digestion enhancement is a key role of the parasympathetic nervous system. During peaceful and relaxed states, the parasympathetic branch stimulates digestive processes effectively.
It increases salivation, promotes the release of digestive enzymes, and boosts the activity of the stomach and intestines. These actions ensure proper breakdown of food and nutrient absorption.
Enhancing digestion is crucial for maintaining overall health and energy levels. In contrast, the sympathetic branch inhibits digestion during stressful situations, diverting energy to more critical responses like muscle activation and alertness.