INTRODUCTION TO THE AUTONOMIC NERVOUS SYSTEM

Below you are given an problem to answer that will test your understanding of the autonomic nervous system. In order to get the most out of this exercise, make sure you work through each part from start to finish, and READ all of the accompanying text. Click the button below to access a printable worksheet to fill in as you work through the exercise.

Due to the level of interactivity required, it is recommended that you complete this exercise on a laptop or desktop computer.

THE EXERCISE:

You are on placement in the Emergency Department at the local hospital. Over the course of a week, three different patients have been referred for toxicology screens due to suspected poisoning/overdose. The consultant in Emergency Medicine asks you to review the patients’ clinical notes and suggest the probable causative agent in each case.
 
Below are the signs/symptoms for each patient, and three different candidate drugs. Using your knowledge of the autonomic nervous system, match each drug to the correct patient profile.

*cocaine has more than one site of action. It also inhibits the dopamine transporter (DAT) on dopaminergic terminals.

**the signs/symptoms that present with organophosphate poisoning are highly variable and depend on the dose as well as the route of  (and the time following) exposure. For the purpose of this exercise, the mechanism of action and the presenting signs/symtoms have been simplified.

HOW TO APPROACH THE PROBLEM:

It’s always best to start with the “normal”. Think about the tissues/organs responsible for the the patient’s signs and symptoms, and what controls these processes under normal, physiological conditions. Then work out how each of the drugs would affect each process based on it’s specific mechanism of action. You should then be able to match each drug to each patient profile.

 

The exercises below should help you work through this step-by-step.

AUTONOMIC CONTROL OF PHYSIOLOGICAL FUNCTION

Below you are given five different “drag and drop” exercises – one for each tissues relevant to the patients’ signs/symptoms. Use the arrows to navigate between the different tissue types.

 

NOTE – not all drop zones need to be filled and not all “droppable elements” need to be used. In this exercise upwards/downwards arrows can mean increase/decrease OR activate/inhibit (but make sure YOU know the difference…)

WHERE DO THE DRUGS ACT?

Below you are given three images depicting an overview of the autonomic nervous system (one for each drug). Based on their mechanisms of action find the regions where each drug would exert their effects.

PREDICTED EFFECTS OF THE DRUGS:

Using the answers from the exercises above, you should now be able to predict the physiological effect each drug would have on the different tissues. Fill in the blanks below.

THE ANSWERS:

You should now be able to assign the most likely causative agent for each patient!