Part 1: Viewing Questions

Learning intention: I can describe how the autonomic nervous system coordinates the body’s responses to stimuli.

Watch Crash Course Anatomy & Physiology: Autonomic Nervous System #13. Answer the questions as you watch.

1. What type of body functions does the autonomic nervous system control?

2. What are the two main divisions of the autonomic nervous system?

3. What is the main role of the sympathetic division?

4. What is the main role of the parasympathetic division?

5. How many neurons usually carry a message from the central nervous system to an organ in the autonomic nervous system?

One neuron

Two neurons

Three neurons

6. What chemical messenger is released by all preganglionic autonomic neurons?

Part 2: Compare, Apply and Reflect

Complete the comparison. Use the video to record the missing information.

Feature

Role

Origin

Ganglia location

Fibre lengths

Sympathetic

____________________________

Preganglionic: ________
Postganglionic: ________

Parasympathetic

____________________________

Preganglionic: ________
Postganglionic: ________

7. You suddenly hear a loud crash and think you are in danger. Which division responds first? Describe two changes it may cause in your body.

8. Exit ticket: In one sentence, explain how the autonomic nervous system helps your body respond to a stimulus.

Teacher Answer Key

1. Involuntary functions, such as heart rate, breathing, digestion and gland activity.

2. The sympathetic and parasympathetic divisions.

3. It prepares the body for action, often called the fight-or-flight response.

4. It supports rest, digestion and recovery, often called the rest-and-digest response.

5. Two neurons: a preganglionic neuron and a postganglionic neuron.

6. Acetylcholine.

Comparison: Sympathetic—fight or flight; thoracolumbar origin; ganglia close to the spinal cord; short preganglionic and long postganglionic fibres. Parasympathetic—rest and digest; craniosacral origin; ganglia near or within target organs; long preganglionic and short postganglionic fibres.

7. Sympathetic division. Possible changes include increased heart rate, widened airways, pupils enlarging, reduced digestion and increased blood flow to skeletal muscles.

8. Answers should explain that the autonomic nervous system detects or receives information about a stimulus and automatically coordinates changes in organs and glands.