Transcript Reflex Arc - Cloudfront.net

Do Now: 3 Types of Neurons
Glue your
DO NOW on
the next blank
page of your
notebook.
Texting and Driving
Reaction Time Drills for a Goal Keeper
Reaction Time
Discussion Questions
Talking Only…
Which position on the soccer field do
you THINK having a
fast reaction time would be the
greatest advantage?
forward/striker, midfield, defense, goal keeper
Reaction Time Drills for a Goal Keeper
What does the nervous system do?
 The Nervous System
includes the brain, spinal
cord, nerves, and sense
organs
 Allows communication
between different parts
of the body
 Allows you to sense (see,
hear, etc.), comprehend,
AND respond (usually
muscle) to the
environment
How does the nervous system work?
 The nervous system is
made of special cells
called neurons
 Neurons transmit
electrochemical
signals to each other
(they “fire”)
– “electrical” signals
– Chemical
(neurotransmitter)
release
How does the nervous system work?
 SENSE
– Sensory neurons: sense stimuli
(things you react to, like pain,
heat, pressure, etc.) in your
environment
 COMPREHEND
– Interneurons: connect sensory
neurons to motor neurons; located
in the brain/spinal cord
 RESPOND
– Motor neurons: make your
muscles respond (taking your
hand away from something hot)
How does the nervous system work?
 If you think before you
respond, the involved
interneurons are in
your brain.
 If you have to react
FASTER, the
interneuron is in your
spinal cord. You react
WITHOUT thinking,
which is called a reflex.
What is a reflex arc?
 Many situations call for immediate
action.
– If your finger touches a hot stove…
you don’t want to waste time
sending information to your brain!!!
– You want to be able to move your finger
off the burner before you burn yourself.
Reflex Arc
 To help you avoid injury, reflex arc
provides a way for immediate withdrawal
from danger!
How does it work?
Normal
Stimulus
Spinal
Cord
Brain
Spinal
Cord
Body
How does it work?
 Information from the stimulus travels to
your spinal cord.
 Even before the information is relayed to
your brain…
– Neurons in the spinal cord automatically
activate the appropriate motor neurons.
 (These motor neurons activates specific parts of
the body)
Reflex Arc
Stimulus
Sensory
neuron
Receptor
in skin
Spinal
cord
Motor
neuron
Muscle
Reflex Arc
Checking for Understanding
Questions
1. What is a reflex arc?
• Explain in YOUR OWN WORDS.
• Give 1 example.
Draw pictures OR write a paragraph to explain
2. What is the path of communication in
a reflex arc?
Draw a flow chart OR write a paragraph to explain