1. The Nervous System
“The right half of the brain controls the left half of the body. This means that only left handed people are in their right mind.”

2. The Nervous System The Nervous System Central Nervous System (CNS)
Peripheral Nervous System (PNS)
Brain
Spinal Cord
Motor Neurons
Sensory Neurons
Somatic Nervous System
voluntary movements via skeletal muscles
Autonomic Nervous System
organs, smooth muscles
Sympathetic
- “Fight-or-Flight” responses
Parasympathetic
- maintenance

3. Central Nervous System
Made up of brain and spinal cord
Acts as body’s control center, coordinates body’s activities
Impulses travel through the neurons in your body to reach the brain
Central Nervous System is yellow in this diagram.

4. Peripheral Nervous System
Made up of all the nerves that carry messages to and from the central nervous system.
Similar to telephone wires that connect all of our houses in the community
Central Nervous System and Peripheral Nervous System work together to make rapid changes in your body in response to stimuli.
Peripheral Nervous System is green in this diagram.

5. Peripheral Nervous System: 2 parts
Somatic Nervous System
Relay information between skin, skeletal muscles and central nervous system
You consciously control this pathway by deciding whether or not to move muscles (except reflexes)
Reflexes: Automatic response to stimulus
Autonomic Nervous System
Relay information from central nervous system to organs
Involuntary: You do not consciously control these
Sympathetic Nervous System: controls in times of stress, such as the flight or fight response
Parasympathetic Nervous System: controls body in times of rest

6. CNS
PNS
Sensory division
Motor division
Sympathetic
division
Autonomic
nervous
system
Somatic
nervous
system
Parasympathetic
division

7. Neurons The basic unit of structure and function in the nervous system
Cells that conduct impulses.
Made up of dendrites, cell body and an axon

8. Structure of the Neuron
cell body (soma): the central part of the neuron, contains the nucleus
regulates cell functioning
dendrites: the branching part of the neuron that receives messages from other neurons and relays them to the cell body

9. Structure of the Neuron
axon: the long, cable-like extension that delivers messages to other neurons
myelin sheath: layer of fatty tissue that insulates the axon and helps speed up message transmission
multiple sclerosis: deterioration of myelin leads to slowed communication with muscles and impaired sensation in limbs
knobs: structure at the end of one of the axon’s branches that releases chemicals into the space between neurons, when the neuron is fired

10. From Neuron to Neuron
≈100 billion neurons in a human brain, connected to an average of 10,000 others; some up to 100,000
synapse: the place where an axon of one neuron meets with the dendrite/cell body of another neuron

11. How is an impulse transmitted?
Stimulus excites sensory neuron.
Depolarization (a change in charge due to sodium ions) creates a wave of changing charges down the axon.
Impulse moves across synapse (tiny space between one neuron’s axon and another’s dendrites) with the help of neurotransmitters
This is an image of neurons located in the cerebral cortex of a hamster.

12. From Neuron to Neuron

13. From Neuron to Neuron
neurotransmitters: a chemical that sends signals from one neuron to another over the synapse

14. From Neuron to Neuron
Neurotransmitters are stored in vesicles in the knobs, and bind to receptors on the cell membrane of the next neuron.
Each receptor can only bind with one kind of neurotransmitter.

15. 3 types of neurons
Sensory Neurons: carry impulses from inside and outside the body to brain and spinal cord.
Interneurons: found within brain and spinal cord, process incoming impulses and pass them on to motor neurons.
Motor Neurons: carry impulses away from the brain and spinal cord.

16. So how do these neurons work if someone taps you on the shoulder . . .
Receptors in the skin sense touch or other stimuli.
Sensory neurons transmit the touch message.
Information is sorted and interpreted in the brain. A response in determined by interneurons.
Motor neurons transmit a response message to the shoulder muscles.
The shoulder muscles are activated, causing the head to turn.

17. The Central Nervous System
Three main sections
Cerebrum
2 hemispheres
Controls memory, intelligence, muscles
Cerebellum
Controls balance, posture and coordination
Brainstem
Controls involuntary activities such as breathing

18. The Cerebrum
Controls conscious activities, intelligence, memory, language, muscles.
Wrinkled with countless folds and grooves and covered with an outer layer of gray matter called the cerebral cortex.
Divided into 4 lobes

19. Largest Lobe Planning Complex Thinking Reasoning Imagining
Frontal Lobe
Largest Lobe
Planning
Complex Thinking
Reasoning
Imagining

20. Parietal Lobe Process messages related to: Touch Taste Temperature
Controls muscle movements

21. Receives input from the eyes
Occipital Lobe
Processes Sight
Receives input from the eyes
Interprets color and other aspects of vision

22. Temporal Lobe
Processes:
Hearing
Some Memory
Speech

23. LEFT vs RIGHT

24. Corpus Callosum
The Corpus Callosum is the part of the brain that allows communication between the two hemispheres.
It is responsible for transmitting neural messages between both the right and left hemispheres.

25. Right brain vs left brain damage
Difficulties in understanding language
Difficulty in speaking and verbal output
Sequencing difficulties
Impaired logic
Decreased control over the right side of the body
Visual-spatial impairment
Visual memory deficits
Left neglect
Decreased awareness of deficits
Altered creativity and music perception
Decreased control over the left side of the body

26. The Cerebellum
Muscle coordination is developed here as well as the memory of physical skills.
If the cerebellum is injured, your movements become jerky.
When you see an amazing athlete perform, you are watching a well-trained cerebellum at work.

27. Cerebellum Coordination and voluntary movement Balance and equilibrium
Coordinates fine movements

28. The Brainstem Made up of the medulla oblongata, pons and midbrain.
Medulla oblongata controls involuntary activities such as heart rate and breathing
Pons and midbrain act as pathways connecting various part of the brain with each other.
Sometimes called the reptilian brain, because it resembles the entire brain of a reptile.

29. Brainstem Controls essential survival functions: Breathing Heart Rate
Swallowing
Reflexes to seeing and hearing
Controls sweating, blood pressure, digestion, temperature
Affects levels of alertness
Brainstem

30. Limbic System
Regulates: Temperature Blood Pressure Heart Rate

31. Thalamus
The thalamus is similar to a doctor that diagnoses a patient's disease or sickness.
It diagnoses different sensory information that is being transmitted to the brain. It is like a “Switch Board” receiving messages and directing them to the proper area.
It directs the sensory information to the different parts and lobes of the cortex.

32. Hypothalamus Hunger and Thirst Maintains a constant temperature.
Connects the endocrine system with the nervous system

33. Amygdala
When you think of the amygdala, you should think of one word. Fear.
The amygdala is the reason we are afraid of things outside our control.
It also controls the way we react to certain stimuli, or an event that causes an emotion, that we see as potentially threatening or dangerous

34. Hippocampus
Plays important roles in the consolidation of short term memory to long term memory
Memory of the location of objects or people.