Download Nervous System Notes

Nervous System
MS-LS1-3: Use argument supported by evidence for how the body is a system
of interacting subsystems composed of group of cells.
MS-LS1-8: Gather and synthesize information that sensory receptors respond
to stimuli by sending messages to the brain for immediate behavior or storage
as memories.
I. Function (job) of the Nervous
System
A. The main role of the nervous
system is to relay electrical signals
through the body.
1. The nervous system directs
behavior and movement, and
along with the endocrine system,
controls physiological processes
such as digestion, circulation, etc.
2. Responds to stimulus
B. Two Systems within a
System
1. Peripheral Nervous System
(PNS)– communication
pathways (nerves) that
connect all areas of body to the
Central Nervous System.
2. Central Nervous System
(CNS)- brain, and spinal cord:
processes all incoming
and outgoing messages.
Question
1. What is the main job of the nervous
system?
2. What are some of the activities the
nervous system controls in our bodies?
3. Explain the difference between the
Central Nervous System and the
Peripheral Nervous System.
a.
b.
Question
1.
What is the main job of the nervous system? relay
electrical signals through the body and to process all
incoming and outgoing messages.
2. What are some of the activities the nervous system
controls in our bodies?
Movement, digestion, circulation, response to
Stimulus/messages.
3. Explain the difference between the Central Nervous
System and the Peripheral Nervous System.
a. Peripheral Nervous System are the communication
pathways (nerves) that connect all areas of body to the
CNS.
b. Central Nervous System [CNS]- brain, and spinal
cord: processes all incoming and outgoing messages.
II. Organs (Parts) that Support the Nervous
System
A.
Major Parts of Peripheral
Nervous System (PNS)
1.
Neuron- specialized cells that
transfer messages throughout
the body in the form of fast –
moving electrical energy.
a. Dendrites – branched
extensions at the end of
neurons to receive info.
b. Axon- fibers that transmit
information.
c. Synapse – space between
the receptors and the axon.
2. Receptors – specialized sensory
dendrites detect changes inside
and outside the body.
ex. Receptors in eye can detect
light (electromagnetic input)
3. Motor Neurons- neurons that
send impulses from the brain and
spinal cord to other body systems.
ex. Receptors can detect
movement or touch (mechanical
signals)
4. Nerves- axons bundled together
with blood vessels and connective
tissue sends and receives info
*Found throughout the body
B. Major Organs of Central Nervous System (CNS)
1. Brain has hundreds of different jobs.
a. Controls body system processes.
– Involuntary processes= process of the body we don’t have to
think about for them to function.
• Ex. Heart beating and blood moving in the circulatory system, food moving
through the digestive system.
– Voluntary processes= process of the body that we choose or
think about for them to function.
• Ex. Muscles and bones working together to walk, or raise your hand.
(locomotion)
b. Responds to Stimuli
- Reflex – responses to
stimuli that the brain
controls automatically
ex. Pulling hand
away from hot stove,
ducking when a ball
flies at face.
- Reaction– responses
to stimuli that you have
control over or choose
to do.(learned)
ex. Putting your hand
up to catch the ball
instead of ducking, or
raising your hand when
teacher asks a question
c. 3 Main Parts of Brain:
Cerebrum – Where we think, and
most memories are stored.
- Two hemispheres (left
controls the right side of the
body/ right controls the left side
of the body)
Cerebellum – Receives sensory
impulses from skeletal muscles
and joints to keep track of your
body’s position.
-Helps keep balance.
Brain Stem – Connects to the
spinal cord
- Controls blood pressure, heart
rate, and involuntary breathing
2. Spinal Cord
a. Contains neurons and axons that pass
impulses to and from the brain.
b. Surrounded by vertebrae (protective
bones)
c. Nerve fibers enable brain to communicate
with peripheral nervous system.
3. Sensory Organs
a. eyes
b. ears
c. nose
d. mouth
e. skin
Questions
1. Given the parts of the nervous system tell what
each is responsible for.
a. neuronb. dendrites –
c. axond. synapse –
e. receptors –
f. motor neuronsg. nervesh. braini. spinal cord –
j. sensory organs -
Questions
1. Given the parts of the nervous system tell what job each
is responsible for.
a. neuron- transfer messages
b. dendrites – receive info
c. axon- transmit info
d. synapse – space between the receptors and the axon
e. receptors – detect changes inside and outside the body
f. motor neurons- neurons that send impulses from the
brain and spinal cord to other body systems
g. nerves- send and receive info
h. brain- think, control movement, store info and memories
i. spinal cord – pass impulses to and from the brain
j. sensory organs – respond to stimulus like light
(electromagnetic), sound, touch (mechanical), smell,
hormones (chemical) etc.
III. Information Processing
A. The brain’s main role is to process all
information (incoming and outgoing
messages) for immediate response or
storage of memories.
B. Information is received by sense
receptors.
C. Signals or inputs that are received by the
brain are processed and result in immediate
behaviors or memories.
Three Main Type of Sensory
Inputs
1.
Electromagnetic ~
response to light.
– Sensory organ: Eyes
a. The Eye: converts
electromagnetic energy that is
light into nerve impulses.
These signals then travel
along nerve cells to the brain,
for immediate use.
Ex – Walking into sunlight from a
dark room and squinting.
Visual Perception: Sensory
intake of visual stimuli must be
processed by brain into organized
structures (i.e., perception) the
eye by itself cannot organize
visual input into shapes that
correspond to objects…this is the
brain’s job.
Ex. The first time you see
something you don’t know what it
is, your brain has to categorize it
(like first time seeing a
labradoodle, or capybara).
Three Main Types of Sensory Inputs (cont.)
2. Mechanical ~ response to movement
or touch.
• Sensory Organs: Ears and Skin
a. Ears
• Sound is the perception of
moving-air waves
b. Skin the body’s largest sensory organ.
• Millions of skin receptors mix and
match to produce specific
perception:
-Ex. Temperature distinct spots on
skin that register only hot or cold
- Ex. Pain warns us of impending
danger; crucial to survival
OUCH ! Pull hand back!
I hear and see dog growling..don’t pet!
Kinesthetic Sense (balance)
• Provides information
about position of joints,
muscles, limbs.
• Gives us control over
body movements
–
Ex: When you close
your eyes, you can still
touch your nose
–
Ex. Leaning when you
ride a bike around a
corner.
3. Chemical ~ response to chemicals in the body such as hormones
(adrenaline) and outside stimuli (out of the body) odors, pheromones
-Sensory organ: nose and mouth
a. Response to chemicals in the body
Ex. Hormones – adrenalin (fight or flight, super strength)
b. Response to chemicals out of the body
Ex. Smell
– Olfaction: sense of smell / use your nose (smell that reminds you of
your grandma)
– Receptors send the neural signals to the brain, passing the thalamus
(memory) and the limbic system (emotions) along the way
– This is why odors often trigger emotional memories
Ex. Taste
– Gustation: sense of taste
– Taste buds: bumps on the tongue surface, back of throat, and inside
the cheeks
– Detect molecules of substances that have dissolved in saliva
– Four types: sweet, sour, salty, and bitter
Three Main Types of Input (cont.)
3. Chemical ~ response to chemicals in
the body such as hormones (adrenaline)
and outside stimuli (out of the body)
odors, pheromones
• Sensory Organs: Nose and Mouth
a. Response to chemicals in the body
-Ex. Hormones – adrenalin
(fight or flight, super strength)
b. Response to chemicals out of the
body
- Ex. Pheromones- chemicals
secreted by our bodies that trigger a
response
Ex. Smell
Olfaction: Sense of smell- use
your nose (smells that reminds
you of your grandma)
• Receptors send the neural
signals to the brain,
passing the thalamus
(memory) and the limbic
system (emotions) along
the way
• This is why odors often
trigger emotional
memories
Ex. Taste
Gustation: Sense of taste
• Taste Buds: Bumps on the
tongue surface, back of
throat, and inside the
cheeks
• Detect molecules of
substances that have
dissolved in saliva.
• Four types: Sweet, sour,
salty, and bitter.
Question
• What is the main job of the brain?
• What are the 3 main types of inputs and
what do they respond to?
Question
• What is the main job of the brain?
The brain’s main role is to process all information
(ingoing and outgoing messages) for immediate
response or storage of memories.
• What are the 3 main types of inputs and what do
they respond to?
1. Electromagnetic ~ response to light.
2. Mechanical ~ response to movement or touch.
3. Chemical ~ response to chemicals in the body
and outside stimuli (out of the body)