Unit 12
C. 31
The Nervous System
(pages 896 – 919)
The Human Body
Name _____________________________
- The only thing worse than being blind is having sight but no vision.
- Helen Keller
Section 1. The Neuron (pages 896 – 900)
Obj. 1. Identify the functions of the nervous system.
Obj. 2. Describe the function of neurons.
Obj. 3. Describe how a nerve impulse is transmitted.
1. What are the functions of the nervous system?
2. Compare the peripheral and the central nervous systems.
3. What is the function of the following neurons? (page 897)
a. Sensory neurons –
b. Motor neurons –
c. Interneurons –
4. Draw a diagram of a neuron. Include cell body, dendrites, axons and myelin sheath.
5. What are the functions of the dendrites, axons and myelin sheath?
6. In a resting neuron, how does the electrical charge inside the cell membrane compare to
the electric charge outside the membrane?
7. Why is an impulse described as a sudden reversal of the resting potential?
8. What is meant by threshold stimulus? How does the brain determine if a stimulus is weak
or strong? (page 899)
9. How are nerve impulses passed on from one neuron to another? (page 900)
Section 2. The Central Nervous System (pages 901 – 904)
Obj. 1. Discuss the functions of the Brain and Spinal cord.
Obj. 2. Describe the effects of drugs on the brain.
1. What are the three major regions of the brain?
2. Explain the role of the spinal cord.
3. How do reflexes protect the body from injury?
4. List the main functions of the following areas of the brain.
a. Cerebrum –
b. Limbic system –
c. Thalamus and Hypothalamus –
d. Cerebellum –
e. Brain Stem –
5. Describe three ways that drugs affect synapses that use the neurotransmitter dopamine.
6. Why do many drug users begin to take more and more of the drug they abuse?
Section 3. The Peripheral Nervous System (pages 906 – 908)
Obj. 1. Describe the functions of the sensory division of the peripheral nervous system.
Obj. 2. Describe the functions of the motor division of the peripheral nervous system.
1. What is the Peripheral Nervous System? (page 906)
2. What is the function of the sensory division of the peripheral nervous system?
3. What is the function of the motor division of the peripheral nervous system?
4. What is the function of the Somatic Nervous system? (page 907)
5. Explain how the neurons work together to allow you to lift a book.
6. Explain the sequence of the reflex arc. Is a reflex a part of the central nervous system, the
peripheral nervous system, or both?
7. How do the sympathetic and parasympathetic nervous systems relate to each other.
Section 4. The Senses (pages 909 – 913)
Obj. 1. Discuss the sense of touch and identify the various types of sensory receptors in the skin
Obj. 2. Explain the relationship between smell and taste.
Obj. 3. Identify the parts of the ears that make hearing and balance possible.
Obj. 4. Describe the major parts of the eye and explain how the eye enables us to see.
1. What three types of sensations to receptors in the skin respond to?
2. How are the senses of smell and taste similar?
3. What are the five basic tastes detected by taste buds? Why can’t you taste food when you
have a bad cold?
4. Describe the sequence of structures that allow you to hear. What is the function of the
cochlea?
5. How do the semicircular canals help you with your balance?
6. You can spin in a circle for a while and then if you stop you still feel dizzy. Why does this
happen?
7. What are the functions of the following structures of the eye?
a. Cornea –
b. Iris –
c. Pupil –
d. Lens –
e. Retina –
f. Rod cells –
g. Cone cells –