science nervous system

1. What is the
basic unit
of the
nervous
system

8. there are billions of
neurons in the body.
Some exist alone.
Others are joined
together to form
organs like the brain
and spinal cord.

9. There are twelve
to fourteen
billions of
neurons in one
part of the brain
alone

10. The basic parts of a neuron

11. Cell body /Soma it is the
central part of a neuron

12. Dendrite the branchlike structure
of the neuron that extends from
the cell body to receive an impulse
- root-like structures or treelike
extensions

13. Dendrites
carry impulses towards the cell
body. A cell may have as many as
200 dendrites carrying impulses
toward the cell body. A single
dendrite can be over one meter
long.

14. Axon the part of the
neuron that transmits
impulses away from
the cell body
-root-like structures

15. Axon carry impulses away from the cell
body. Axons pass impulses to the
dendrites of other neurons or cell
body of muscle cells. Axons can
be grouped together into cable-
like bundles called nerves

17. Control of Body Processes through
the Nervous System
The nerve impulse

18. Neurons are cells with the special
ability to carry signals or impulses.
Thoughts, emotions, learning, and
many body functions are carried by
nerve impulses in the neurons.
A nerve impulse is a combination of
an electrical charge and a chemical
reaction

19. A nerve impulse is not a flow
of electricity, but
an electrochemical signal
moving along a neuron

20. Impulse an
electrochemical
gradient moving
along a neuron

21. A nerve impulse cannot
jump from one neuron to
another. When a nerve
impulse comes to the end of
an axon, it produces the
chemical, called
neurotransmitter, to be
released.

22. The chemical crosses the
space between
neurons called synapse and
stimulates the nerve
impulse to start in the next
dendrite.

23. The nerve impulse is sent by
neurotransmitters from one neuron to
another through a gap called synapse

25. Which part of the body receives
information?

26. The nervous system is assisted
by five sense organs - the
eyes,
ears, nose, tongue, and skin.
These sense organs are
constantly receiving
information from the
environment and sending
messages to the brain

27. A stimulus (plural: stimuli) is any
factor in the environment that may
trigger a nerve impulse.

28. Stimuli - Anything that can causes an
organism to react

29. A response is a reaction to a
stimulus.
A stimulus is received by the
body and a response is made.
An organism must be able to
respond to a stimulus in order
to survive.

30. Messages do not travel in
both directions along the
same neuron. Only the axon
of the neuron releases
neurotransmitters that cross
the space between neurons.

31. Reaction time is the
length of time between
application of a stimulus
and detection of a
response

32. Use your body’s senses to detect
the stimuli in your
environment and execute the
corresponding response

33. How Fast is Your
Reaction?

34. Objective:
• Measure the length of
time of response to catch
a dropped object

36. Q3. With which hand did you
catch the ruler faster when your
eyes were open?
Q4. With which hand did
you catch the ruler faster
when your eyes were
closed?

37. Q5. Did you catch the ruler
faster with your eyes open or
closed?
Q5. The ruler was
caught faster with
eyes open

38. Q6. Explain why a message
moving along nerve pathways
takes time.
Q6. The message travels from
one neuron to another until it
reaches the brain. Then, the
brain’s response is also
transmitted by another set of
neurons.

39. .
Q7. Describe the nerve pathway
that the message followed when
you saw the ruler fall
First, the eye sees the ruler, then
sends a message to the brain. The
brain sends a response through the
muscles in the hand. Finally, the
muscles contract to allow the
person to catch the ruler.

40. KEY CONCEPT TO EMPHASIZE:
Neurons have the special
ability to carry signals or
impulses.
A nerve impulse is an
electrochemical signal
moving along an active
neuron.

41. The space between neurons is
called synapse.
A stimulus is any factor in the
environment that influences
behavior.
A response is a reaction to a
condition or stimulus.

42. To survive, an organism must
be able to respond to a
stimulus.
Reaction time is the length of
timem between application of
a stimulus and detection of a
response.

43. Performance Task:
Design a flyer that will
disseminate information
about the different diseases
affecting
the human nervous system.
NOTE: ALL HANDWRITTEN