chapter 15 the nervous system 15.1 how the nervous system works 15.2 divisions of the nervous system...
TRANSCRIPT
Chapter 15 The Nervous System
15.1 How the Nervous System Works
15.2 Divisions of the Nervous System
15.3 Sight and Hearing
15.4 Smell, Taste, and Touch
15.5 Alcohol and Other Drugs
Table of ContentsChapter Preview
15.1 How the Nervous System Works
15.2 Divisions of the Nervous System
15.3 Sight and Hearing
15.4 Smell, Taste, and Touch
15.5 Alcohol and Other Drugs
Chapter 15 The Nervous System
Chapter Preview Questions
1. Which part of the skeletal system protects the brain?
a. spine
b. pelvis
c. skull
d. joint
Chapter 15 The Nervous System
Chapter Preview Questions
1. Which part of the skeletal system protects the brain?
a. spine
b. pelvis
c. skull
d. joint
Chapter 15 The Nervous System
Chapter Preview Questions
2. Which muscles can you control voluntarily?
a. heart muscles
b. leg muscles
c. diaphragm
d. stomach muscles
Chapter 15 The Nervous System
Chapter Preview Questions
2. Which muscles can you control voluntarily?
a. heart muscles
b. leg muscles
c. diaphragm
d. stomach muscles
Chapter 15 The Nervous System
Chapter Preview Questions
3. What is the smallest unit of any body system?
a. structure
b. organ
c. tissue
d. cell
Chapter 15 The Nervous System
Chapter Preview Questions
3. What is the smallest unit of any body system?
a. structure
b. organ
c. tissue
d. cell
Chapter 15 The Nervous System
Chapter Preview Questions
4. What is the eye designed to receive from the environment?
a. light rays
b. vibrations
c. lenses
d. motion
Chapter 15 The Nervous System
Chapter Preview Questions
4. What is the eye designed to receive from the environment?
a. light rays
b. vibrations
c. lenses
d. motion
Chapter 15 The Nervous System
You smell a delicious aroma. You walk into the kitchen and see a bag of popcorn in the microwave. You hear some kernels still popping. Then you think to yourself, “Snack time!” Which body systems enabled you to smell, walk, see, hear, and think? How did each system play a part in your response?
How do organs and other structures enable the nervous system to function?
Chapter 15 The Nervous System
Suffixes
Suffix Meaning of Suffix Example and Meaning of Example
A person or thing that-ant Pollutant Something that pollutes or makes dirty
Chapter 15 The Nervous System
Suffixes
Suffix Meaning of Suffix Example and Meaning of Example
Action or practice of-ism Criticism Action of judging the value of something
Chapter 15 The Nervous System
Suffix Meaning of Suffix Example and Meaning of Example
Condition of; state of-ness Sickness Condition of being sick
Suffixes
Chapter 15 The Nervous System
Suffix Meaning of Suffix Example and Meaning of Example
Having; full of-ous Disastrous Full of disaster
Suffixes
Chapter 15 The Nervous System
Apply It!
1. What is the suffix in the word nearsightedness? What does the
suffix mean?
-ness; it means the condition of being nearsighted
2. The word stimulate means “to increase activity. ” Predict the
meaning of stimulant. Revise your definition as needed after
you read Section 5.
Sample answer: It means something that increases activity.
Revised definition: A stimulant is a drug that speeds up body processes.
Chapter 15 The Nervous System
End of Chapter Preview
Chapter 15 The Nervous System
Section 1: How the Nervous
System WorksWhat are the functions of the nervous system?What is the structure of a neuron and what kinds of neurons are found in the body?How do nerve impulses travel from one neuron to another?
Chapter 15 The Nervous System
The Neuron
A neuron has a large cell body that contains the nucleus, threadlike extensions called dendrites, and an axon.
Chapter 15 The Nervous System
How a Nerve Impulse Travels
For a nerve impulse to be carried along at a synapse, it must cross the gap between the axon and the next structure. The axon tips release chemicals that carry the impulse across the gap.
Chapter 15 The Nervous System
More on Nerve Impulses
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Chapter 15 The Nervous System
Nervous System
Click the Video button to watch a movie aboutthe nervous system.
Chapter 15 The Nervous System
End of Section: How the Nervous
System Works
Chapter 15 The Nervous System
Section 2: Divisions of the Nervous System
What are the structures and functions of the central nervous system?What are the structures and functions of the peripheral nervous system?What is a reflex?What are two ways in which the nervous system can be injured?
Chapter 15 The Nervous System
Central Nervous System
The central nervous system is the control center of the body. It includes the brain and spinal cord.
Chapter 15 The Nervous System
Nervous System Activity
Click the Active Art button to open a browser window and access Active Art about nervous system.
Chapter 15 The Nervous System
The Brain
There are three main regions of the brain that receive and process information. These are the cerebrum, the cerebellum, and the brain stem.
Chapter 15 The Nervous System
Peripheral Nervous System
The peripheral nervous system consists of a network of nerves that branch out from the central nervous system and connect it to the rest of the body. The peripheral nervous system is involved in both involuntary and voluntary actions.
Chapter 15 The Nervous System
ReflexesA reflex is an automatic response that occurs very rapidly and without conscious control.
Chapter 15 The Nervous System
ReflexesA reflex is an automatic response that occurs very rapidly and without conscious control.
Chapter 15 The Nervous System
End of Section: Divisions of the Nervous System
Chapter 15 The Nervous System
Section 3: Sight and Hearing
How do your eyes enable you to see?How do you hear and maintain your sense of balance?
Chapter 15 The Nervous System
Vision
You eyes respond to the stimulus of light. They convert that stimulus into impulses that your brain interprets, enabling you to see.
Chapter 15 The Nervous System
Virtual Dissection of the Eye Activity
Click the Active Art button to open a browser window and access Active Art about a virtual dissection of the eye.
Chapter 15 The Nervous System
Vision
Light coming from an object enters your eye and is focused by the lens. The light produces an upside-down image on your retina. Receptors in your retina then send impulses to your cerebrum, which turns the image right-side up.
Chapter 15 The Nervous System
Hearing and Balance
Your ears are the sense organs that respond to the stimulus of sound. Ears convert the sound to nerve impulses that your brain interprets.
Chapter 15 The Nervous System
Sound Intensity
Sound intensity, or loudness, is measured in units called decibels. The threshold of hearing for the human ear is 0 decibels. For every 10-decibel increase, the sound intensity increases ten times. Thus, a 20-decibel sound is ten times more intense than a 10-decibel sound. A 30-decibel sound is 100 times more intense than a 10-decibel sound. Sound levels for several sound sources are shown in the bar graph.
Chapter 15 The Nervous System
Sound Intensity
Decibels, or sound level; type of sound
Reading Graphs:
What unit of measure is represented on the y-axis? What is represented on the x-axis?
Chapter 15 The Nervous System
Sound Intensity
20dB; 60dB; 120dB
Interpreting Data:
What is the sound intensity in decibels of a whisper? Normal talking? A rock concert?
Chapter 15 The Nervous System
Sound Intensity
20 dB vs. 60 dB, which is 10,000 times more intense
Calculating:
How much more intense is normal talking than a whisper? Explain.
Chapter 15 The Nervous System
Sound Intensity
Rock concert; jet plane taking off
Predicting:
Based on the graph, what types of sound could be painful if you were exposed to them?
Chapter 15 The Nervous System
End of Section: Sight and Hearing
Chapter 15 The Nervous System
Section 4: Smell, Taste, and Touch
What are the functions of the nervous system?What is the structure of a neuron and what kinds of neurons are found in the body?How do nerve impulses travel from one neuron to another?.
Chapter 15 The Nervous System
Smell and Taste
The senses of smell and taste work closely together. Both depend on chemicals in food or in the air. The chemicals trigger responses in receptors in the nose and mouth.
Chapter 15 The Nervous System
Links on the Senses
Click the SciLinks button for links on the senses
Chapter 15 The Nervous System
End of Section: Smell, Taste, and Touch
Chapter 15 The Nervous System
Section 5: Alcohol and Other Drugs
What are the functions of the nervous system?What is the structure of a neuron and what kinds of neurons are found in the body?How do nerve impulses travel from one neuron to another?
Chapter 15 The Nervous System
Drug Abuse
Drug abuse can have serious consequences. However, there are ways to tell if someone is abusing drugs and ways to help that person.
Chapter 15 The Nervous System
Alcohol
Alcohol is a drug found in many beverages, including beer, wine, cocktails, and hard liquor. Alcohol is a powerful depressant and affects every system of the body.
Chapter 15 The Nervous System
Links on Drug Addiction
Click the SciLinks button for links on drug addiction.
Chapter 15 The Nervous System
End of Section: Alcohol and Other Drugs
Chapter 15 The Nervous System
QuickTake Quiz
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