1. The Nervous System

2. 4 Functions of the Nervous System
Receiving
Specialized receptors located throughout body, allow signals to be received and then sent to processing centre.
2. Processing
Information transmitted from the nerves to a processing centre (ex. brain)
Decode meaning of message transmitted

3. 4 Functions of the Nervous System
3. Storing
Short-term
Long-term
4. Transmitting
Transmit information received from a processing centre through nerves to other parts of the body.

4. A system that controls all of the activities of the body.
Nervous System
A system that controls all of the activities of the body.
The nervous system is made of:
The brain
The spinal cord
The nerves
The senses

5. The Central Nervous System The Peripheral Nervous System
Brain
Spinal cord
The Peripheral Nervous System
The Nerves

6. The Neuron The nervous system functions with the help of neurons.
They are specialized nerve cells in the nervous system that receive and transmit messages.
The human body has an average of 100 billion neurons!!!

7. The Neuron Parts of the neuron
Dendrites – receive message
Cell body - contain nucleus
Axon – transmit message
Axon terminals – send message

8. Role of Neurons
To pick up stimuli, transform them into nerve impulses and transmit these impulses.

9. The nervous system also allows you to react to a stimulus.
A stimulus is a change in the environment.
Example: A hot stove
Or… tripping over a rock

10. Nerve Impulse
An electrical signal transmitted by a neuron

11. Characteristics of the Neuron
Can be stimulated – reacts to stimulus by changing it into nerve impulse
Conductive – transmits nerve impulse from one neuron to another until reaches its target
Consumes a lot of Oxygen and Glucose. Lives only a few minutes without oxygen
Live more than 100 yrs.
Cannot reproduce or be replaced if destroyed

12. Transmission of nerve impulses
A nerve impulse travels from neuron to neuron until it reaches its target.
It travels from dendrites to axon terminals

13. Transmission of nerve impulse
Dendrites receive messages/stimuli and transform them into nerve impulses
Nerve impulses are then transmitted along axons to axon terminals

14. Transmission of nerve impulses
Nerve impulses travel from one to another by Neurotransmitters (chemical substances) secreted by axon terminals
The transition zone between 2 neurons is called a synapse.

15. Nerve Impulses
Nerve impulses move quickly from neuron to neuron and can reach up to speeds of 430km/h.
Making sure there is rapid transmission of information to many parts of body.

16. Nerve Axons of neurons combine to form nerves.
They are covered by protective tissue and blood vessels
A nerve is a structure that helps transmit info between CNS and rest of body

17. Peripheral Nervous System
Connects different parts of body to the CNS.
Made up of all the nerves that run throughout the body.

19. Peripheral Nervous System
Sensory Receptors
Specialized nerves
Pick up stimuli and transform it into nerve impulses
Found throughout body
Ex: receive information that let muscle know how much muscle should stretch

20. Peripheral Nervous System
Sensory Nerves
Transmit information picked up by the sensory receptors.
Transmission in the form of nerve impulses.
Ex: Optic nerve – sensory nerve
Transmits information captured by the eye to the brain.
Also pick up internal stimuli from vital organs.

21. Peripheral Nervous System
Motor Nerves
Transmit impulses from the CNS to the muscles in order to produce voluntary and involuntary movements.
Ex: Cardiac and Respiratory rates increase when blood oxygen levels are too low…
Ex: When we want to lift an arm, brain sends signal telling muscles to contract.

22. Central Nervous System
The Brain
The Spinal Cord

23. The Brain

24. The Brain Meninges – A membrane that covers the brain and spinal cord
Protected by :
The skull/cranium
Meninges – A membrane that covers the brain and spinal cord

25. The Brain
Communication
12 pairs of nerves known as cranial nerves

26. Parts of the Brain
Cerebrum
Cerebellum
Brain Stem

27. Cerebrum Command Centre for: All voluntary movements
Interpretation of senses
Intelligence
Centre of emotions

28. Cerebrum
Divided into 4 lobes

29. Cerebrum Frontal: emotion, reasoning, planning, movement, speech
Parietal: touch, pain, taste, pressure, temperature
Temporal: hearing, memory, meaning, language
Occipital: vision

30. Divided into 2 Hemispheres
Right Hemisphere
Controls left side of body
Left Hemisphere
Controls right side of body

31. Parts of the Cerebrum White matter Outer layer: Grey matter
Cerebral Cortex – directs
higher brain function like
planning or reasoning
Inner layer:
White matter

32. 5 Functions of Cerebrum Controls voluntary movements
Interprets messages picked up by the senses
Controls Intelligence
Controls Emotion
Regulates physiological functions (hunger, alertness, body temperature)

33. The Cerebellum 2 Functions:
Centre of balance and movement coordination
Helps us to do many activities all at once

34. Cerebellum Helps us to:
Run, speak, play piano, dance without falling down

35. Cerebellum Motion sickness and vertigo are disorders
that occur when the
cerebellum responds to
contradictory signals

36. The Brain Stem Attached to spinal cord, cerebrum and cerebellum
Also known as the MEDULLA

37. The Brain Stem 2 Functions: Controls internal stimuli
Controls involuntary movement

38. The Brain Stem Example: Eating, swallowing,sneezing
It will signal organs and glands to start working to help with proper digestion of food

39. The Spinal Cord 2 Functions:
Carries information from different parts of the body to the brain
The reflex centre

40. The Spinal Cord What is a reflex?
A rapid involuntary reaction to a stimulus
Allows for quick reaction time in an emergency
Ex: Blinking, pulling arm away from sharp object

41. The Spinal Cord Reflex Arc The series of nerve impulses that occur
during a reflex is
known as a:
Reflex Arc

42. The Reflex Arc Nerve Impulse travels much shorter distance
Takes short cut and
bypasses brain
Occurs rapidly
Automatically
redirected to muscles

43. Staying Sharp! Physical activity
Challenging your brain (mental activities)
Interacting with people (social activities)
Positive thinking (reduce stress factors)
Healthy eating habits
Getting enough sleep!
Don't do drugs...

44. The End

45. Disorders

46. Stroke Symptoms: Deterioration in vision (double vision)
Slurred speech
Sudden weakness or loss of sensation in one limb or arm/leg (usually same side)
Lack of coordination
Severe symptoms: loss of consciousness
Partial or complete paralysis

47. Stroke Causes: Blood supply to the brain is disrupted
Nerve tissue affected by lack of oxygen loses ability to function and dies
Could be due to : atherosclerosis, blood clot, cerebral hemorrhage, high blood pressure

48. Stroke Treatments: Depend on location and type of stroke
Surgery (remove blood leak from hemorrhage)
Medications
Hospitalization, rehabilitation (physiotherapy)

49. Alzheimer’s Disease Symptoms: Gradual loss of memory
Inability to learn new information
Tendency to repeat oneself, misplace objects
Increasing irritability, anxiety, depression
Confusion

50. Alzheimer’s Disease Causes: Degeneration of brain
Specific causes unknown
Increased chance with age
Course of disease can run from a few to 15 yrs or more…

51. Alzheimer’s Disease
Treatments: 1. Some medications can treat behavior 2. Continue daily routine and activities 3. Home or hospital care to assist with living 4. Patience on the part of caregiver

52. Parkinson’s Disease Symptoms: Shaking at rest
Reduction of facial expression
Slowness of movements
Shuffling walk
Stiffness or rigidity of limbs
Difficulty in speech, writing, swallowing and chewing
Progresses slowly

53. Parkinson’s Disease Causes:
Chemical necessary to transport signals from one nerve cell to the other is lost
Specific cause is unknown

54. Parkinson’s Disease Treatments: Exercise and therapy
Medications can help by restoring chemical needed for transfer of electrical impulses
Surgery

55. Multiple Sclerosis (MS)
Symptoms:
numbness, weakness or paralysis in limbs
Impaired vision
Tremors, lack of coordination
Symptoms can diminish or disappear (remission), but can recur (relapse)

56. Multiple Sclerosis (MS)
Causes: usually between ages of 20-40
Disease of CNS
Inflammation in area of nervous system resulting in destruction of outer coating of nerve cell, leaving areas of scarring (sclerosis)
Specific cause unknown

57. Multiple Sclerosis (MS)
Treatments:
Medications can help control symptoms, reduce inflammation, provide temporary relief
Physical therapy
No cure

58. Meningitis Symptoms: Fever, sever headache, vomiting
Confusion or drowsiness
Stiff neck
Sever cases: coma or seizures

59. Meningitis
Causes:
Bacterial infection and inflammation of the meninges and cerebrospinal fluid
Caused by infections in other parts of body
(respiratory, heart, bones, ear, sinus, nose, tooth)
3. Usually occurs in children but can strike at any age

60. Meningitis Treatments: Antibiotics depending on the type of bacteria
Drainage of accumulated fluids may be necessary