Table of Contents
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
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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
Section 1: �How the Nervous �System Works
Use the reading summary and pages 600- 604 in the textbook to answer questions 1-15, #6 RG & NT: How the Nervous System Works. Use the video tutorial on The Neuron for the nerve cell diagram on the last page.
Chapter 15 The Nervous System
1. Three jobs of the �nervous system
a. Receives information
b. Directs body’s response to information
c. Maintains homeostasis
of the nervous system.
False
Chapter 15 The Nervous System
3. From what two places does the nervous system receive information?
The environment
Inside the body
4. Stimulus 5. False
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6. How does the nervous system help maintain homeostasis?
The nervous system DIRECTS the body to RESPOND appropriately to the INFORMATION it receives.
Chapter 15 The Nervous System
7-10 The Neuron
A neuron has a large cell body that contains the nucleus, threadlike extensions called dendrites, and an axon.
C – B – D - A
11. A neuron can have only ONE axon,
but can have many dendrite extensions
12. A bundle of nerve fibers is called
a NERVE.
Click for video
Myelin Sheath
Chapter 15 The Nervous System
sensory neurons – receive information
receptors
Interneurons-
interpret information
found in brain
and spinal cord
Motor neurons-
attached to muscle
causes movement
13. Path of A Nerve Impulse
Chapter 15 The Nervous System
How a Nerve Impulse Travels
14. For a nerve impulse to be carried along at a synapse, it must cross the (gap) between the axon and the next structure.
15. Chemicals are released by the axon tips allowing the nerve impulse to cross the gap of the synapse.
Chapter 15 The Nervous System
Section 2: Divisions of the Nervous System
Chapter 15 The Nervous System
Central Nervous System
Q 1-3 The Central Nervous System is the control center of the body. It includes the brain and spinal cord.
All neurons in the brain are
interneurons.
Chapter 15 The Nervous System
4. What helps protects the BRAIN from injury?
b. Layers of connective tissue (Meninges)
c. CerebralSpinal fluid
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Q 6-10 Parts of the BRAIN
The cerebrum is the largest part
of the brain. Different areas of the
cerebrum control such functions
such as speech, movement, the senses
and abstract thought.
The cerebellum coordinates
the actions of muscles and helps
maintain balance.
The brainstem controls
Involuntary actions such as
breathing and heart rate.
Chapter 15 The Nervous System
11-12 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.
The right half of the cerebrum
Is associated with creative and
artistic ability.
The left half of the cerebrum
is associated with math and
logical thinking.
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
14. What protects the SPINAL CORD?
click for video
b. Layers of connective tissue… ya know meninges.
c. A watery fluid…ya know Cerebral-spinal fluid (CSF).
Chapter 15 The Nervous System
15. Peripheral Nervous System –
A network of 43 pairs of nerves that branch out from the CNS and connect to the rest of your body.
Chapter 15 The Nervous System
16. Somatic Nervous System –
Controls voluntary actions like using a fork or tying your shoelaces.
Next to Q 16 draw a simple picture of a fork and a simple picture of a shoe with laces
Chapter 15 The Nervous System
15. Peripheral Nervous System –
A network of 43 pairs of nerves that branch out from the CNS and connect to the rest of your body.
Chapter 15 The Nervous System
16. Autonomic Nervous System –
Controls involuntary actions - contractions of smooth muscles that adjust the diameters of blood vessels, digestion, breathing.
Next to Q 16 draw a simple picture of an eye and a simple picture of a heart
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Reflexes
A reflex is an automatic response that occurs very rapidly and without conscious control.
Chapter 15 The Nervous System
Reflexes
A reflex is an automatic response that occurs very rapidly and without conscious control.
Chapter 15 The Nervous System
A concussion is a bruise like injury to the brain.
Wear a helmet during some activities to protect your head and always wear a seatbelt in the car.
Chapter 15 The Nervous System
Spinal Cord Injury
All the nerve axons in that region are damaged, so impulses cannot pass through them, causing a loss of movement in some part of the body.
Chapter 15 The Nervous System
A concussion is a bruise like injury to the brain.
Wear a helmet during some activities to protect your head and always wear a seatbelt in the car.
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How the Eye Sees Objects
Light enters the eye through the pupil
The lens focuses the light
Focused light rays strike the retina
Receptor cells (rods & cones) respond to light
Rod & cone cells send electrical impulses to the brain
The brain interprets signal and produces image
Chapter 15 The Nervous System
Inside the Eye
Cone cells work best in
good light and allow us
to see color.
Rod cells work best in dim
light and we see shades of
Grey.
Light
enters
the
eye
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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.
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The image is turned right-side up
The images from each eye are combined to form a single image.
+
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Focusing the Lens
| Seeing Far Away | Seeing Close Up |
What do the Ciliary muscles do? | Relax | Contract |
What happens to The lens? | Becomes thin | Becomes thick |
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Having both eyes at the front of the head enabled humans to see in three dimensions & for depth perception
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Hearing… our Ears
sound
sound
sound
cochlea
Semi-circular
canals
Ear drum
Sounds are made by a material that is vibrating or
moving back and forth.
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. The cochlea is a snail-shaped tube that is lined with receptors that respond to sound.
Chapter 15 The Nervous System
Section 4: Smell, Taste, and Touch
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Smell and Taste
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Gustatory Cells
Commonly called taste buds- organs on your
tongue that respond to chemicals in food.
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Attack of the giant taste bud
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Smell and Taste
Both depend on chemicals in food or in the air. The chemicals trigger responses in receptors in the nose and mouth.
Olfactory bulb
50
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The 5 main taste sensations
Sweet
Sour
Salty
Bitter
Meat-like or Umami - savory
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A stuffy nose decreases your ability to smell food
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Touch
There are 6 different
touch receptors
for hot, cold, pain,
pressure, touch
and fine touch.
They are located close to the surface of the skin, they let you feel when something brushes against you.
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Pain alerts the
body to possible
danger and
directs us to stop
a behavior
that may do us
Harm.
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Section 5: Alcohol �and Other Drugs
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Graphic Organizer
Depressant
Slows down the CNS
Sleepiness
Slows reaction time
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Any chemical that causes changes
in a person’s body or behavior is a
DRUG
The deliberate misuse of drugs for
purposes other than medical ones is called
DRUG ABUSE
Many abused drugs are Illegal, abused
drugs affect the body very shortly after
they are taken.
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Tolerance
Tolerance
Tolerance
Tolerance
Tolerance
Tolerance
Needing larger and larger amounts
of a drug to produce the same effects
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Mood Altering Drugs
Mood Altering Drugs- They affect patterns of thinking and the way in which the brain interprets information from senses.
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Steroid Use / Anabolic Steroids
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Steroid use is especially dangerous for developing teens. Steroid use can permanently damage growing bodies.
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Alcohol
Alcohol is quickly absorbed by the
Digestive System
B.A.C.
Blood Alcohol Concentration
1/10th of 1% of fluid in blood is alcohol
Thohugt pcrosecs
Judgment
Reaction time
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Chemical Dependence or addiction is a chronic disease of the brain. Addiction has nothing to do with a person's morals, education, social class or ethnicity. It is a primarily genetic illness that runs in families. Doctors and other professionals use this definition: Addiction is characterized by the repetitive, intermittent, loss of control over the use of a mood altering drug that causes problems in a person's life. Addiction is not defined by how much or how often people use - it is defined by what happens when they use.
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.
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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.
Alcohol abuse can cause
the destruction of cells in the brain & liver it leads to addiction and emotional dependence.
Chapter 15 The Nervous System