1. The Nervous System Major division - Central vs. Peripheral
Central Nervous System
Peripheral Nervous System
Major division - Central vs. Peripheral
Central or CNS- brain and spinal cord
Peripheral- nerves connecting CNS to muscles and organs

2. Peripheral Nervous System
3 kinds of neurons connect CNS to the body
sensory
motor
interneurons
Motor - CNS to muscles and organs
Sensory - sensory receptors to CNS
Interneurons: Connections Within CNS
Spinal
Cord
Brain
Nerves
key words: peripheral nervous system

3. Peripheral Nervous Systemk e l t a ( o m i c ) y p h P r s A u n N v
key words: peripheral nervous system; skeletal nervous system; somatic nervous system; autonomic nervous system; sympathetic nervous system; parasympathetic nervous system

4. Somatic System Nerves to/from spinal cord
control muscle movements
somatosensory inputs
Both Voluntary and reflex movements
Skeletal Reflexes
simplest is spinal reflex arc
Muscle
Motor
Neuron
Interneuron
Skin receptors
Sensory
Brain

5. Autonomic System Two divisions: Control involuntary functions
sympathetic
Parasympatheitic
Control involuntary functions
heartbeat
blood pressure
respiration
perspiration
digestion
Can be influenced by thought and emotion

6. Sympathetic “ Fight or flight” response
CENTRAL NERVOUS SYSTEM
Brain
Spinal
cord
SYMPATHETIC
Dilates pupil
Stimulates salivation
Relaxes bronchi
Accelerates heartbeat
Inhibits activity
Stimulates glucose
Secretion of adrenaline,
nonadrenaline
Relaxes bladder
Stimulates ejaculation
in male
Sympathetic
ganglia
Salivary
glands
Lungs
Heart
Stomach
Pancreas
Liver
Adrenal
gland
Kidney
“ Fight or flight” response
Release adrenaline and noradrenaline
Increases heart rate and blood pressure
Increases blood flow to skeletal muscles
Inhibits digestive functions
keywords: sympathetic nervous system; fighlt or flight response

7. Parasympathetic “ Rest and digest ” system
CENTRAL NERVOUS SYSTEM
Brain
PARASYMPATHETIC
Spinal
cord
Stimulates salivation
Constricts bronchi
Slows heartbeat
Stimulates activity
Contracts bladder
Stimulates erection
of sex organs
Stimulates gallbladder
Gallbladder
Contracts pupil
“ Rest and digest ” system
Calms body to conserve and maintain energy
Lowers heartbeat, breathing rate, blood pressure
key words: parasympathetic nervous system; rest and digest system

8. Summary of autonomic differences
Autonomic nervous system controls physiological arousal
Sympathetic
division (arousing)
Parasympathetic
division (calming)
Pupils dilate EYES Pupils contract
Decreases SALVATION Increases
Perspires SKIN Dries
Increases RESPERATION Decreases
Accelerates HEART Slows
Inhibits DIGESTION Activates
Secrete stress
hormones
ADRENAL
GLANDS
Decrease secretion
of stress hormones
key words: sympathetic nervous system; parasympathetic nervous system

9. Central Nervous System
Spinal
Cord
Brain
Brain and Spinal Cord
key words: central nervous system; brain; spinal cord

10. Brain has 2 Hemispheres Left & Right sides are separate
Corpus Callosum : major pathway between hemispheres
Some functions are ‘lateralized’
language on left
math, music on right
Lateralization is never 100%
Left
Hemisphere
Corpus Callosum
Right
key words: left hemisphere; right hemisphere

11. Each hemisphere is divided into 4 lobes
Frontal
Parietal
Occipital
Temporal
key words: cerebral cortex; lobes; frontal; parietal; temporal; occipital

12. Sensory Information sent to opposite hemisphere
Left visual
field
Right visual
Optic
nerves
Corpus
Callosum
Left Visual
Cortex
Right Visual
Principle is Contralateral Organization
Sensory data crosses over in pathways leading to the cortex
Visual Crossover
left visual field to right hemisphere
right field to left
Other senses similar
key words: left hemisphere; right hemisphere; visual infomation; touch information

13. Contralateral Motor Control
Movements controled by motor area
Right hemisphere controls left side of body
Left hemisphere controls right side
Motor nerves cross sides in spinal cord
Somatosensory Cortex
Motor Cortex

14. Corpus Callosum Major ( but not only) pathway between sides
Connects comparable structures on each side
Permits data received on one side to be processed in both hemispheres
Aids motor coordination of left and right side
Corpus Callosum
Medial surface of right hemisphere
Example : You read a geometry problem in a textbook. The words are seen and the visual forms translated into meaning by the language center in the left hemisphere. To solve the problem you have to imagine a cone shaped object. This is accomplished by centers in the right hemisphere. The solution is written down using language generated by the left hemisphere.
What would happen in cases like this if the callosum was damaged ?

15. Corpus Callosum What happens when the corpus callosum is cut?
Sensory inputs are still crossed
Motor outputs are still crossed
Hemispheres can’t exchange data
key words: left hemisphere; right hemisphere; corpus callosum; epilepsy
One method used to treat severely epileptic patients involves cutting the corpus callosum to prevent the spread of seizures acorss the entire brain. The video clip on this slide shows a man who has had such a surgery. Double click on video to start video clip. This clip discusses the types of information processing deficits associated with cutting the corpus callosum and shows a task often used to assess corpus callosum damage. This task is also represented in drawing form on the following slide as well.

16. The ‘Split Brain’ studies
Surgery for epilepsy : cut the corpus callosum
Roger Sperry, 1960’s
Special apparatus
picture input to just one side of brain
screen blocks objects on table from view
Nonverbal
right
hemisphere
Verbal
left
key words: left hemisphere; right hemisphere; corpus callosum; epilepsy
This slide is a schematic of the task shown in the video clip on the previous slide

17. The ‘Split Brain’ studies
I saw an
apple.
“What did
you see?”
Nonverbal
right
hemisphere
Verbal
left
Nonverbal
right
hemisphere
Verbal
left ??
“What did
you see?”
“Using your left hand,
Pick up what you saw.”
Picture to right brain
can’t name the object
left hand can identify by touch
Picture to left brain
can name the object
left hand cannot identify by touch

18. Localization of function
Frontal
Parietal
Occipital
Temporal
key words: cerebral cortex; lobes; frontal; parietal; temporal; occipital

19. Occipital Lobe Input from Optic nerve Contains primary visual cortex
most is on surface inside central fissure
Outputs to parietal and temporal lobes
Occipital
Lobe
Visual
Lobe

20. Temporal Lobe Contains primary auditory cortex
Inputs are auditory, visual patterns
speech recognition
face recognition
word recognition
memory formation
Outputs to limbic System, basal Ganglia, and brainstem
Temporal
Lobe

21. Parietal Lobe Inputs from multiple senses
Somatosensory
Cortex
contains primary somatosensory cortex
borders visual & auditory cortex
Outputs to Frontal lobe
hand-eye coordination
eye movements
attention

22. Frontal Lobe Contains primary motor cortex No direct sensory input
Working
Memory
Motor
Cortex
Broca’s
Area
Contains primary motor cortex
No direct sensory input
Important planning and sequencing areas
Broca’s area for speech
key words: cerebral cortex; lobes; frontal; motor functions
Frontal lobe is not directly involved in sensation or perception. Its functions are related to motor action (behavior). The motor cortex is the start of nerves that run through the spinal cord to the muscles.
Broca’s area organizes sequences of speech movements. Damage leads to productive aphasia
Dorsolateral Prefrontal Cortex is important in working memory. WM is short term memory for information needed to maintain a context, to prepare for the next step in a sequence of thought, and /or to inhibit irrelevant responses
The wisconsin card sorting task illustrates the importance of working memory in maintaining context and inhibiting irrelevant responses
Prefrontal area for working memory

23. Frontal Lobe Disorders
Broca’s area
productive aphasia
Prefrontal area
lose track of ongoing context
fail to inhibit inappropriate responses
Often measured with the Wisconsin Card Sorting Task
key words: cerebral cortex; lobes; frontal; motor functions

24. Wisconsin Card Sorting Task
Row of 4 example cards set out
Patient is given a deck of 64 different cards
Told to place each card under the one it best matches
key words: frontal lobe; perseverence; Wisconsin Card Sorting task
This slide and the following Wisconsin Card Sorting Task (WCST) slides give an example of one of the types of deficits seen in patients with frontal lobe damage. Frontal lobe patients often have problems with perseverance (e.g. switching strategies when an old strategy is ineffective). In the WCST after the patient has figured out the rule (e.g. color) the examiner switches to a new rule (e.g. shape or number). Frontal patients make errors after a rule switch for a longer time than normals, because they perseverate on (fail to inhibit) the old rule.
Told correct or incorrect after each card
Correct!
Must deduce what the underlying rule is.

25. The Nervous System: Summary
Major structures of the nervous
CNS, Somatic, Autonomic
Two hemispheres & 4 lobes
Organization
contralateral input & output
primary sensory areas
motor areas
Commissure
Localization of functions
Central Nervous System
Peripheral Nervous System