1. Chapter 5 - Section 1
Nervous System

2. 2

3. Ner vous System

4. Ner vous System
!Any internal or external change that brings
about a response is called a stimulus

5. Ner vous System
!Any internal or external change that brings
about a response is called a stimulus
!Noise, light, the smell of food, and the
temperature of the air are all stimuli from outside
your body.

6. Ner vous System
!Any internal or external change that brings
about a response is called a stimulus
!Noise, light, the smell of food, and the
temperature of the air are all stimuli from outside
your body.

7. Ner vous System
!Any internal or external change that brings
about a response is called a stimulus
!Noise, light, the smell of food, and the
temperature of the air are all stimuli from outside
your body.
!Chemical substances such as hormones are
examples of stimuli from inside your body.

8. Keeping ever y thing in order

9. Keeping ever y thing in order
!The regulation of steady, life-maintaining
conditions inside an organism, despite changes in
its environment, is called homeostasis.

10. Keeping ever y thing in order
!The regulation of steady, life-maintaining
conditions inside an organism, despite changes in
its environment, is called homeostasis.
!Examples:
!Regulating breathing
!Regulating heartbeat
!Regulating digestions

11. Ner ve Cells

12. Neurons are made up of a cell body and branches
celled dendrites and axons.

13. Axons carry impulses away from the cell body. The axon
branches at the end to send the signal to many other
muscles, neurons, or glands.

14. Types of Ner ve Cells

15. Types of Ner ve Cells
!Motor Neurons ~ Sensory Neurons ~ Interneurons

16. Types of Ner ve Cells
!Motor Neurons ~ Sensory Neurons ~ Interneurons

17. Types of Ner ve Cells
!Motor Neurons ~ Sensory Neurons ~ Interneurons
!Sensory neurons – receive information and send
impulses to the brian or spinal cord, where…

18. Types of Ner ve Cells
!Motor Neurons ~ Sensory Neurons ~ Interneurons
!Sensory neurons – receive information and send
impulses to the brian or spinal cord, where…
!Interneurons – relay these impulses to…

19. Types of Ner ve Cells
!Motor Neurons ~ Sensory Neurons ~ Interneurons
!Sensory neurons – receive information and send
impulses to the brian or spinal cord, where…
!Interneurons – relay these impulses to…
!Motor neurons – conduct impulses from the brain or
spinal cord to muscles or glands throughout the body.

20. Synapses
 Tomove from one neuron to the next, an impulse
crosses a small space called a synapse.

21. Synapses

22. Synapses

24. Synapses

25. Synapses
!When an impulse reaches the end of an axon,
the axon releases a chemical.

26. Synapses
!When an impulse reaches the end of an axon,
the axon releases a chemical.
!This chemical flows across the synapse and
stimulates the impulse in the dendrite of the next
neuron.

27. Synapses
!When an impulse reaches the end of an axon,
the axon releases a chemical.
!This chemical flows across the synapse and
stimulates the impulse in the dendrite of the next
neuron.
!Your neurons are adapted in such a way that
impulses move in only one direction.

28. Synapses

29. Synapses

30. The Central Ner vous System
!The central nervous
system is made up of the
brain and spinal cord.

31. The Central Ner vous System
!The central nervous
system is made up of the
brain and spinal cord.

32. CNS – The Brain

33. CNS – The Brain
!The brain coordinates all of your body activities.

34. CNS – The Brain
!The brain coordinates all of your body activities.

35. CNS – The Brain
!The brain coordinates all of your body activities.
!Made of 100 billion neurons

36. CNS – The Brain
!The brain coordinates all of your body activities.
!Made of 100 billion neurons
!WHAT?!?! 100 billion.....
▪That is absolutely.....

37. CNS – The Brain
!The brain coordinates all of your body activities.
!Made of 100 billion neurons
!WHAT?!?! 100 billion.....
▪That is absolutely.....
!And that is only 10% of all the neurons in the human body.

38. CNS – The Brain
!The brain coordinates all of your body activities.
!Made of 100 billion neurons
!WHAT?!?! 100 billion.....
▪That is absolutely.....
!And that is only 10% of all the neurons in the human body.
!The brain is surrounded by a bony skull and 3 membranes
and a layer of fluid.

39. CNS – The Brain

41. CNS – The Cerebrum

42. CNS – The Cerebrum
!The cerebrum is the largest part of brain

43. CNS – The Cerebrum
!The cerebrum is the largest part of brain

44. CNS – The Cerebrum
!The cerebrum is the largest part of brain
!This is where…
!thinking takes place
!impulses from the senses are interpreted
!memory is stored
!movements are controlled

45. CNS – The Cerebrum
!The cerebrum is the largest part of brain
!This is where…
!thinking takes place
!impulses from the senses are interpreted
!memory is stored
!movements are controlled

46. CNS – The Cerebrum
!The cerebrum is the largest part of brain
!This is where…
!thinking takes place
!impulses from the senses are interpreted
!memory is stored
!movements are controlled
!The outer layer, called the cortex, is marked by
many ridges and grooves (increasing the surface
area).

47. CNS – The Cerebrum

48. CNS - Cerebellum

49. CNS - Cerebellum
!What is interpreted in the cerebellum?
!Stimuli from the eyes and ears
!Stimuli from muscles and tendons

50. CNS - Cerebellum
!What is interpreted in the cerebellum?
!Stimuli from the eyes and ears
!Stimuli from muscles and tendons
!The cerebellum interprets this information and
uses it to coordinate voluntary muscle movement,
maintain muscle tone, and helps maintain
balance.

51. CNS – The Cerebellum