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Module 1 The Nervous System

Lesson 1.1.1

1.1.1 page 3

Self-Check

SC 1. Complete this Self-Check activity which compares the autonomic nervous system with the somatic nervous system.

 

Self-Check

Test yourself to see whether you have learned the concepts in this lesson.

SC 1. Define homeostasis. Illustrate your answer by using body temperature as your example.

 

SC 2. Explain why the nervous system is critical for maintaining homeostasis.

 

SC 3. Identify what basic neural pathway is involved as you dodge a misdirected tennis ball.

 

SC 4. How is the autonomic nervous system different from the somatic nervous system?


SC 5. Why do you have to learn how to walk but not how to breathe?

 

Check your work.
Try This Self-Check Answers

SC 1. Homeostasis is the maintenance of a nearly constant internal environment that fluctuates about a set point or an ideal point. For example, the set point for body temperature is 37oC. However, the temperature hovers around that value, either below or above, by a small amount.

 

SC 2. The human nervous system is capable of regulating thousands of activities simultaneously. The overall function of the nervous system is to collect information, analyze (sort, integrate, interpret) the information, and to initiate an appropriate response to maintain a state of dynamic equilibrium or homeostasis. The nervous system accomplishes this function quickly and precisely. Quick action is often needed to get you out of dangerous situations.

 

SC 3. A sense organ, in this case the eye, detects the ball and the sensory neuron (optic nerve) carries the message to the brain. At this point an interneuron interprets the information and sends a message via a motor neuron which causes muscles to act to withdraw, e.g., to move the head out of the way of the ball.

 

SC 4. The somatic nervous system, which takes messages via motor neurons to the skeletal muscles of the body, is controlled by the conscious part of the brain (cerebrum) and causes voluntary (conscious) movements of the muscles. The autonomic nervous system, composed of sympathetic and parasympathetic motor neurons, carries messages to cardiac and smooth muscles. This causes an involuntary (not necessarily conscious) contraction of these muscles.

 

SC 5. A person needs to learn how to contract muscles of the skeleton (voluntary control by the somatic nervous system). However, one does not need to learn how to contract smooth or cardiac muscle (involuntary control by the autonomic nervous system) or how to carry out reflexes which are automatic.