Lesson 1.1.1

Lesson 1—The Structure and Organization of the Nervous System

 

Get Focused

Remember from the Big Picture when you were in a room full of people and you hoped to meet a new friend? You started to breathe fast and your heart rate went up as you made your approach. It took an effort to calm yourself down. In this situation, you could not control your breathing rate and your heart rate, but you did have control of your legs.

 

nervous system: an elaborate communication system that receives input, processes, integrates, stores information, and triggers muscle contraction or glandular secretion

 

homeostasis:  a state of body equilibrium or a stable internal environment of the body

Can you imagine being able to control your breathing and heart rates like you control your legs? This is where the nervous system gets divided into the unconscious or involuntary sections and the conscious or voluntary parts. Processes vital to life, like breathing, are controlled unconsciously. Just try to see how long you can hold your breath. In this lesson you will explore mechanisms that increase your breathing rate and slow it down, returning you to a normal or balanced state. This state is termed homeostasis.

 

Controlling your skeletal muscles, such as your legs, is a conscious or voluntary act. In Lesson 1 you will discover the part of the nervous system responsible for voluntary control and what happens when these pathways are interrupted.

 

Injuries, such as paralysis or the loss of a limb, can interrupt communication in the conscious nervous system. In the case of someone recovering from a car accident, this person may learn how to walk again through the re-establishment of conscious nervous system communications. This may be achieved through physiotherapy, surgery, and other technologies developed to enhance or repair communication pathways.

 

In this lesson you will investigate the following focusing questions:

  • How is the nervous system organized, and how do these parts communicate with each other?

  • What interrupts the normal communication mechanisms of the sympathetic and parasympathetic parts of the nervous system?

While you are working through Lesson 1, you will start working on the module assessment.

The picture shows a vehicle badly damaged in a car accident.

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sympathetic nervous system: division of the autonomic nervous system that activates the body to cope with some stressor, such as danger, excitement, or fear; sometimes referred to as the fight, fright, flight subdivision

 

parasympathetic nervous system: division of the autonomic nervous system that oversees digestion, elimination and glandular function; often works opposite the sympathetic nervous system to bring the body back to normal

 


Module 1: Lesson 1 Assignments

 Once you have completed all of the learning activities for this lesson, you can complete the online assignment.

Bio 30 1.1.1 online assignment

Here is a tutorial video for this lesson that you can watch if it suits your learning style.  Bio30 tut# 1.1.1

** The Self-Check and Try This questions in this lesson are not marked by the teacher; however answering these questions will help you review important information and build key concepts that may be applied in future lessons. You can respond to these mentally, write out your response, or record your answer in any other way that works for you. **