CHAPTER REVIEW QUESTIONS

Earth Physiology

1. Describe the general anatomical features of the brain.
   

2. Describe the anatomy of the spinal cord.
   

3. Describe the nerve structures coming from the brain and spinal cord and name the parts of the body that are served by them.
   

4. Three classes of neurons make up the communication system of the body. All parts of the body are connected to this communication system. Name the three classes, their function and how the body's communication system works.
   

5. In what locations of the body do the signals that neurons transmit originate? Describe the different origination sites.
   

6. Neurons, when destroyed, are not replaced by the body. Explain how neurons are protected and preserved in the brain, the spinal cord and the rest of the body.
   

7. Why can you stand or whirl around without falling down?
   

8. When a motor signal travels to a muscle site and reaches a gap, what is the name of this gap and what events occur so that the signal can travel across the gap to activate the muscle?
   

Space Physiology

1. The neurovestibular system is responsible for the balance mechanisms in the body. Why does this system not function the same way in space to provide the needed support to the balance mechanisms?
   

2. Explain the term nystagmus.
   

3. What sensory organ is considered the "window" to the vestibular system? Name two ocular methods that can be used to measure vestibular function. (Hint: The hint is in the question!)
   

4. Select one of Dr.Young's hypotheses and, using any of the data sets in this chapter, provide an argument that supports or refutes the hypothesis.
   

5. 1. When the astronauts return to Earth, they go through a period of disorientation. Is this similar to what happens when they first go into space? Explain.
   2. Physiologically, what does their body do to overcome this disorientation?

6. What do the astronauts do while in space to reduce the magnitude of space sickness?
   

CRITICAL THINKING