a. faster than neurons without myelin sheaths. c. slower than neurons without myelin sheaths.
b. at the same speed as neurons without myelin sheaths. d. in greater numbers than neurons without myelin sheaths.
____7. Messages take the form of electrical signals, and are known as
a. sensory neurons b. nerve impulses c. motor neurons d. reflex arc
____8. The depolarization and repolarization of a neuron membrane is called
a. action potential b. resting potential c. excitability d. propagation
____9. What are the spaces between adjacent neurons called?
a. reflex arc b. effector c. synaptic cleft d. resting potential
____10. What is the function of neurotransmitters?
a. hurl neurons through synapses to create new nerve impulses
b. chemically link neurons across the synapse to conduct impulses
c. receive and transmit ultrasound waves across synapses
d. none of the above
____11. For a neuron to return to its resting potential, it must
a. lose negative charge b. lose positive charge c. gain negative charge d. gain more sodium ions
____12. A change in the environment that may be of sufficient strength to initiate
an impulse is called a(an)
a. excitability b. stimulus c. polarized d. potential
____16. The action that restores a neuron to its resting potential is
a. polarization b. action potential c. depolarization d. refractory period
____17. When a nerve cell is polarized, the inside of the cell membrane is
a. positively charged and the outside is positively charged.
b. positively charged and the outside is negative charged.
c. negatively charged and the outside is negatively charged.
d. negatively charged and the outside is positively charged.
____18. Which description does not apply to all nerve impulses?
a. They follow an all-or-none principle. c. They jump from node to node.
b. They flow at various speeds. d. They flow in only one direction.
____19. If you accidentally touch a hot stove, you pull your finger away before
the impulse is relayed to the
a. spinal cord b. effecter c. brain d. receptor
____20. The somatic nervous system regulates activities that are
a. unconscious control b. involuntary c. conscious control d. automatic
21. For a neuron to achieve Resting Potential, it must move _____________________________ ions out of the cell, and actively pump _____________________________ ions into the cell.
22. At the beginning of an impulse, the ______________________________ gates open.
23. Action Potential is another name for a (an)
24. A(n) _________________________________ is an automatic response to a stimulus.
25. Subdivision of the PNS that regulates the activity of the heart and smooth muscle and of glands; also called the involuntary nervous system. ___________________________________ nervous system.
26. Nerves that carry messages from the body to the central nervous system make up the ________________________________________ nervous system.
27. What are the two major division of the peripheral nervous system?
51. What is the basic functional unit of the nervous system?
52. Subdivision of the PNS that controls voluntary activities such as the activation of skeletal muscles. ______________________________________________________.
For questions 53-58, match the following answers to one of the statements below.
A. Resting Potential D. Sodium-potassium pump
B. Action Potential E. Depolarization
C. Repolarization F. Refractory Period
____ 53. K+ moves out of the axon
____ 54. Charges inside the axon change positive.
____ 55. Active transport system.
____ 56. Axon is not conducting an impulse.
____ 57. Time when the axon cannot conduct an impulse.
____ 58. Axon is depolarized, then repolarized.
DIRECTIONS: Answer the questions below as completely and as thoroughly as possible. Answer the question in essay
form (not outline form), using complete sentences. You may use diagrams to supplement your answers, but a diagram alone
without appropriate discussion is inadequate. See me if you need Help, Have Problems or Questions or To Check Your
1. What is the relationship between afferent neurons, interneurons, and efferent neurons?
2. What role does the sodium-potassium pump play in the restoration of the membrane potential?
3. Explain the difference between an afferent neuron and an efferent neuron.
4. Describe how the patellar (knee-jerk) reflex operates.
5. What are the functions of the Nervous System that enables the body to respond quickly?
6. Explain how the relative concentrations of sodium ions and potassium ions inside and outside a neuron change during an action potential.
7. Describe the process of the nerve impulse from the point at which the nerve has been stimulated.
8. Most organs in the body are stimulated by both the sympathetic division and the parasympathetic division of the autonomic nervous system. Explain how this helps maintain homeostasis and what each division does.
9. A neuron consists of three main parts, List Them and their Main Function:
10. How does the autonomic nervous system work to maintain homeostasis?
11. Describe the role of neurotransmitters in transmitting a signal across a synaptic cleft.
12. Explain how a signal in the nervous system is transmitted between adjacent neurons?
13. Contrast resting potential with action potential.
14. Explain the importance of the refractory period and what occurs during the refractory period.