Module 1 The Nervous System

Read

You must know the structure of the spinal cord to understand how it performs its role in the nervous system. Read pages 385 and 386 in your textbook. Make brief summary notes for your course folder.

 

The spinal cord is a major communication link between the brain and the peripheral nervous system (PNS). As you learned in your reading and in the video, the spinal cord is protected by the backbone and cerebrospinal fluid. You will learn about the role of protection to the nervous system and other functions of this fluid later in this lesson.

 

The spinal cord is made up of two special types of nerves. Sensory nerves communicate messages from the body to the brain for interpretation, and motor nerves communicate messages from the brain to effectors that initiate a response. In Lesson 3, you will learn about these communication pathways, and you will discover another communication role of the spinal cord, the reflex arc.

 

Self-Check

SC 2. After you have read the text and made your summary notes, complete the handout titled “The Spinal Cord.” To prepare for the next lesson, you may wish to include with the name of each structure in the diagram a statement about the structure’s composition. For example, a spinal nerve is composed of both sensory and motor neurons. Self-check your answers, and file your work in course folder.

 

Inquiry into Biology (Whitby, ON: McGraw-Hill Ryerson, 2007), 386, fig. 11.23. Reproduced by permission. 

 

The Meninges and Cerebrospinal Fluid

Try This

As you know from your lesson reading, the brain and spinal cord are essential structures in communicating and keeping your body in balance. They must be protected. The following activity reviews the role of the skull, meninges, and cerebrospinal fluid and what happens when the brain gets scrambled.

Use two plastic containers with lids that are a little bit larger than an egg. Put an egg into each container. Fill one container with water. Firmly close each container with the lid. Shake the containers. Make your observations. Consider what part of this demonstration illustrates the skull, the meninges, the cerebrospinal fluid, and the brain. What was the role of the water?

 

TR 1. To review these concepts, you should complete questions 2, 3, and 7 on page 395 of your textbook.

Self-Check

These questions provide the opportunity to review and evaluate your understanding of the concepts in Lesson 2. Complete the questions, self-check your answers, and file your work in your course folder for reference when you study.

 

SC 3. The old saying or adage that “an elephant never forgets” appears to have some scientific basis. What area of the brain would you examine to begin researching about this saying? Describe two technologies that might be useful in this research.

 

SC 4. Five situations in which you may find yourself are described below. Identify the part of the brain involved in processing these situations.

1. _____ You are on a boat. A sudden wind comes up. The boat rocks violently. You feel dizzy and nauseated, and you want to vomit.
2. _____ You are in a restaurant. The waiter brings you the bill. You reach into your pocket to retrieve your wallet.
3. _____ You are on a hike in the mountains, and, all of a sudden, you come upon a grizzly sow with her two cubs. She rears up on her hind legs and growls menacingly. Your heart rate increases dramatically as well as your breathing rate.
4. _____ You see a backpack.
5. _____ You hear a dog barking.

SC 5. Use the diagram of a neural pathway through the spinal cord to answer the next question.

 

 

1. Explain what would happen if only Structure 2 were cut.
2. Explain what would happen if only Structure 4 were cut.
3. Explain what would happen if Structure 5 were cut.