An Important Process

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An Important Process
Interest Grabber
Section 35-1

• While walking along a dusty path, you begin to
  cough. As you continue your walk, a small insect
  comes flying toward you. You blink and then duck
  so that it misses you. These actions are just a
  few examples of homeostasis. Homeostasis is the
  process by which organisms keep internal
  conditions relatively constant despite changes in
  their external environments.

1. List three other examples of homeostasis that
occur in organisms. 2. Why is homeostasis
important to an organism?
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Section Outline
Section 35-1

• 351 Human Body Systems.
• A.Levels of Organization of the Body.
• 1. Cells-basic unit of structure and function.
• Tissues-group of cells that perform a single
  function. Ex. Epithelial, connective, nervous,
  muscle tissues etc.
• Organs-a group of different types of tissues that
  work together to perform a single function.
• Organ Systems-11 systems (slides) pg. 892-893,
  fig. 35-2.

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Figure 35-2 Human Organ Systems Part I
Section 35-1
Nervous System
Integumentary System
Skeletal System
Muscular System
Circulatory System
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Figure 35-2 Human Organ Systems Part I
Section 35-1
Nervous System
Integumentary System
Skeletal System
Muscular System
Circulatory System
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Figure 35-2 Human Organ Systems Part I
Section 35-1
Skeletal System
Nervous System
Integumentary System
Muscular System
Circulatory System
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Figure 35-2 Human Organ Systems Part I
Section 35-1
Muscular System
Nervous System
Integumentary System
Skeletal System
Circulatory System
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Figure 35-2 Human Organ Systems Part I
Section 35-1
Circulatory System
Nervous System
Integumentary System
Skeletal System
Muscular System
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Figure 35-2 Human Organ Systems Part 2
Section 35-1
Respiratory System
Digestive System
Excretory System
Reproductive System
Endocrine System
Lymphatic/Immune Systems
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Section Outline
Section 35-1

• B. Homeostasis-the process by which organisms
  keep internal conditions relatively constant
  despite changes in external environments.
• 1. A Nonliving Example-Heating/cooling system in
  a house. (slide) pg. 895 fig. 35-4.
• In the Body.
• Feedback inhibition.
• Temperature.
• Menstrual cycle.

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Examples of Feedback Inhibition
Section 35-1
Thermostat senses temperature change and switches
off heating system
Room temperature increases
Room temperature decreases
Thermostat senses temperature change and switches
on heating system
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Youve Got a Lot of Nerve!
Interest Grabber
Section 35-2

• The nervous system controls and coordinates
  functions throughout the body. The nervous system
  is one of the bodys communication systems.
  Without communication, parts of the body could
  not work together smoothly.

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Interest Grabber continued
Section 35-2

• 1. Think about tying the shoelace of a sneaker.
  Construct a flowchart that shows what happens
  between your eyes and your brain, and between
  your brain and your hands, when you tie a bow in
  the shoelace.
• 2. How would the communications be different if
  you tried to tie the shoelace with your eyes
  closed?

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Section Outline
Section 35-2

• 352 The Nervous System-controls and coordinates
  functions throughout the body and responds to
  internal and external stimuli.
• A.Neurons-cells that transmit electrical impulses
  throughout the body.
• Parts of the neuron. (slide) pg. 897, fig. 35-5.
• Cell body.
• Dendrites.
• Axon.
• Myelin sheath.

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A Neuron
Section 35-2
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Section Outline
Section 35-2

• B.The Nerve Impulse.
• The Resting Neuron.
• Outside of cell has net charge.
• Inside of cell has net charge. (2nd).
• Difference in charges caused by active transport
  of ions across the cell membrane.
• Sodium-potassium pump.
• Na ions pumped out.
• K ions pumped in but leak back out easily.
• Causes a net charge.
• Called a resting potential. (3rd ,5th, 6th).

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Figure 35-6 Resting Potential
Section 35-2
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Section Outline
Section 35-2

• 2.The Moving Impulse.
• Begins with a stimulus.
• Stimulus causes a reversal of the membrane
  potential.
• Sodium channels open.
• Na flows into cell.
• Inside becomes more outside becomes .
• Action potential (nerve impulse).
• Self-propagating.

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Figure 35-7 An Impulse
Section 35-2
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Figure 35-7 An Impulse
Section 35-2
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Figure 35-7 An Impulse
Section 35-2
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Figure 35-7 An Impulse
Section 35-2
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Section Outline
Section 35-2

• 3.Threshold.
• Impulse strength is constant.
• Stimulus must be of a certain strength in order
  to cause an impulse.
• This minimum level is the threshold.
• All-or-none principal.

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Section Outline
Section 35-2

• C. The Synapse-Jumping the gap.
• Location at which a neuron can transfer an
  impulse to another cell.
• Neurotransmitters-chemicals used by the neuron to
  transmit an impulse across the synapse.

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Figure 35-8 The Synapse
Section 35-2
Direction of Impulse
Dendrite of adjacent neuron
Axon
Receptor
Vesicle
Axon terminal
Synaptic cleft
Neurotransmitter
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Brainiac
Interest Grabber
Section 35-3

• Imagine that you are a computer systems engineer
  and your job is to design a computer that can
  perform all the functions of a human brain.

1. Which brainlike functions can already be
performed by computers? 2. Which brainlike
functions cannot be performed by computers?
3. How successful do you think you (or anyone)
could be in designing a computer that can perform
all the functions of the human brain? Explain
your answer.
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Section Outline
Section 35-3

• 353 Divisions of the Nervous System.
• A. The Central Nervous System-relays messages,
  processes information and analyzes information.
• B. Part 1-The Brain.
• The Cerebrum-responsible for voluntary activities
  of the body.
• Site of intelligence, learning, and judgment.
• Folds increase the surface area. Lobes.
• Two hemispheres-deal with opposite sides of the
  body.
• Right-controls left side. Site of artistic
  ability.
• Left-controls right side. Analytic ability.

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Figure 35-9 The Brain
Section 35-3
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Section Outline
Section 35-3

• 2. The Cerebellum-back of brain.
• Coordinates muscle movement and balance.
• 3. The Brain Stem-Medulla Oblongata.
• Below cerebellum.
• Regulates the flow of information to rest of the
  body.
• Controls blood pressure, heart rate, breathing,
  swallowing.
• 4. The Thalamus and Hypothalamus.
• Between brain stem and cerebellum.
• Thalamus-receives sensory input and sends it to
  the proper region of the brain.
• Hypothalamus-controls and regulates hunger,
  thirst, fatigue, anger, body temperature.

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Section Outline
Section 35-3

• C. Part 2-The Spinal Cord.
• Communications link between the brain and the
  rest of the body.
• Some reflexes directly processed.
• Reflex-a quick, automatic response.

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Cross Section of the Spinal Cord
Section 35-3
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Section Outline
Section 35-3

• D. The Peripheral Nervous System-all of the
  nervous system outside of the central nervous
  system.
• Sensory-transmits impulses from sense organs to
  CNS.
• Motor-transmits impulses from CNS to muscles or
  glands.
• 1. The Somatic Nervous System-regulates
  activities under conscious control.
• 2. The Autonomic Nervous System-regulates
  activities that are involuntary. Divided into to
  parts.
• Sympathetic nervous system-speeds up the
  activity.
• Parasympathetic nervous system-slows down the
  activity.

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Concept Map
Section 35-3
The Nervous System
is divided into
which consists of
that make up
which is divided into
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Taking It All In
Interest Grabber
Section 35-4

• Your sensessight, hearing, smell, touch,
  tasteare constantly receiving information about
  your environment. Even if you are not thinking
  about it, your body is sensing and responding to
  conditions around you, such as the temperature of
  the room.

1. List ten things you observe about the room
you are in. 2. Next to each observation, write
the sense that you used to make that
observation. 3. What sense did you use most?
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Section Outline
Section 35-4

• 354 The Senses-.
• Five categories of sensory receptors.
• Pain receptors-everywhere except the brain.
• Thermoreceptors-skin, body core hypothalamus.
• Mechanoreceptors-skin, skeletal inner ears.
• Chemoreceptors-nose taste buds.
• Photoreceptors-eyes.
• A. Vision-study the diagram pg. 907 fig. 35-13.
• B. Hearing and Balance.
• 1. Hearing-detects vibrations in the air.
• 2. Balance-semicircular canals of inner ear.
• C. Smell and Taste-intertwined-see slide.
• D. Touch and Related Senses.

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Figure 35-14 The Eye
Section 35-4
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The Senses of Smell and Taste
Section 35-4
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Figure 35-15 The Ear
Section 35-4
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Poster Designer
Interest Grabber
Section 35-5

• Imagine that you are working with a local
  community group to help stop drug abuse among
  teenagers. Your first assignment is to design a
  drug abuse awareness poster.

1. Complete a brief sketch of your idea on a
sheet of paper. What effects of drugs does your
poster depict? 2. Why do you think teenagers will
pay attention to your poster?
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Section Outline
Section 35-5

• 355 Drugs and the Nervous System
• A. Drugs That Affect the Synapse
• 1. Stimulants
• 2. Depressants
• 3. Cocaine
• 4. Opiates
• 5. Marijuana
• 6. Alcohol
• 7. Alcohol and Disease
• B. Drug Abuse

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Commonly Abused Drugs
Section 35-5
Used to increase alertness, relieve
fatigue Used to relieve anxiety, irritability,
tension Used to relieve pain
Stimulants Depressants Opiates
Amphetamines Barbiturates Tranquilizers M
orphine Codeine
Increase heart and respiratory rates elevate
blood pressure dilate pupils decrease
appetite Slow down the actions of the central
nervous system small amounts cause calmness and
relaxation larger amounts cause slurred speech
and impaired judgement Act as a depressant
cause drowsiness, restlessness, nausea
Drug Type
Medical Use
Examples
Effects on the body
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Video Contents
Videos

• Click a hyperlink to choose a video.
• Action Potential
• Synaptic Transmission

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Video 1
Video 1
Action Potential

• Click the image to play the video segment.

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Video 2
Video 2
Synaptic Transmission
Click the image to play the video segment.
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Internet
Go Online

• The latest discoveries in the nervous and immune
  systems
• Interactive test
• Articles on the human body
• For links on the nervous system, go to
  www.SciLinks.org and enter the Web Code as
  follows cbn-0352.
• For links on the human brain, go to
  www.SciLinks.org and enter the Web Code as
  follows cbn-0353.
• For links on the senses, go to www.SciLinks.org
  and enter the Web Code as follows cbn-0354.
• For links on drugs and drug abuse, go to
  www.SciLinks.org and enter the Web Code as
  follows cbn-0355.

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Section 1 Answers
Interest Grabber Answers
1. List three other examples of homeostasis that
occur in organisms. Accept all reasonable
student examples that show an understanding of
homeostasis. 2. Why is homeostasis important to
an organism? Homeostasis allows an organism to
remain in balance with its environment. If
homeostasis is not maintained, it can harm the
organism or result in the death of the organism.
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Section 2 Answers
Interest Grabber Answers

• 1. Think about tying the shoelace of a sneaker.
  Construct a flowchart that shows what happens
  between your eyes and your brain, and between
  your brain and your hands, when you tie a bow in
  the shoelace.
• Students flowcharts should include The eyes
  inform the brain about the position of the hands
  and the shoelace the brain signals the hands how
  to move to begin to tie the bow and so on.
• 2. How would the communications be different if
  you tried to tie the shoelace with your eyes
  closed?
• All information about the position of the
  shoelace would have to come from the hands as
  they feel and manipulate the shoelace.

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Section 3 Answers
Interest Grabber Answers
1. Which brainlike functions can already be
performed by computers? Computation and data
sorting 2. Which brainlike functions cannot be
performed by computers? Original thought and
perception of emotions 3. How successful do you
think you (or anyone) could be in designing a
computer that can perform all the functions of
the human brain? Explain your answer. Students
will likely say not successful, because a
computer cannot be designed to feel emotions.
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Section 4 Answers
Interest Grabber Answers
1. List ten things you observe about the room
you are in. Students will likely describe the
shape and color of the room, what is written on
the chalkboard, whether doors or windows are
open, how bright the lighting is, the
temperature, ticking of a clock, rustling of
papers, and so on. 2. Next to each observation,
write the sense that you used to make that
observation. Most observations are likely to be
based on sight and hearing. If students list only
visual observations, have them make some
observations with their eyes closed. 3. What
sense did you use most? Possible answer sight
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Section 5 Answers
Interest Grabber Answers
1. Complete a brief sketch of your idea on a
sheet of paper. What effects of drugs does your
poster depict? Possible answer negative effects
on the brain, which may result in various types
of injuries or death. 2. Why do you think
teenagers will pay attention to your
poster? Answers will depend on the design of the
poster. Teenagers may respond to concern about
loss of mental or athletic ability or concern
about possible injuries.
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End of Custom Shows

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