1. Nervous System Notes Part 1

2. INTERESTING NERVOUS SYSTEM FACTS
Nerve impulses to and from the brain travel as fast as 170 miles per hour.
Ever wonder how you can react so fast to things around you or why that stubbed toe hurts right away? It’s due to the super-speedy movement of nerve impulses from your brain to the rest of your body and vice versa, bringing reactions at the speed of a high powered luxury sports car.
The brain operates on the same amount of power as 10-watt light bulb
Your brain generates as much energy as a small light bulb even when you’re sleeping.

3. NOTES – THE CENTRAL NERVOUS SYSTEM (CNS)
2 parts
1. brain
2. spinal cord

4. Parts of the Brain
BRAINSTEM (4 parts)
1. Medulla Oblongata
Function: regulation of heart rate, breathing, swallowing, vomit response, coughing, sneezing
all involuntary actions

5. 2. Pons
functions as a bridge between the cerebrum and cerebellum

6. 3. Midbrain
functions in hearing and visual reflexes
4. Reticular Activating System (RAS)
located scattered in the brainstem
functions in arousing & maintaining consciousness
damage here results in a coma

7. Cerebellum
processes inputs of cerebral cortex and sensory receptors
results in smooth, coordinated movements of skeletal muscles
injury results in loss of muscle tone and coordination

8. Diencephalon (interbrain)
Thalamus
functions to sort out all the sensory impulses from the body
Hypothalamus
EXTREMELY IMPORTANT in maintaining homeostasis

9. What the hypothalamus controls
Autonomic Control Center
blood pressure, heart rate, digestive tract, eye pupil (involuntary responses)
Emotional Responses
pain perception, pleasure, fear, etc. (limbic system)
body temperature, hunger, thirst, sleep
endocrine system hormones
Hypothalamus Disturbances
body wasting, or obesity, sleep problems, dehydration, emotional imbalances, and more

10. The Cerebrum
gray matter on the surface of the cerebrum
Cerebral Cortex
enables us to perceive, communicate, remember, understand, appreciate and move voluntarily (consciousness)

11. 3 functional areas of the Cerebral Cortex
1. Motor Areas
controls movements of skeletal muscles, speech and eyes
2. Sensory Areas
conscious awareness of sensations (hot, cold, pressure, pain)
3. Association Areas
connect different parts of the cortex
involved in recognizing smells, tastes, etc.

12. Examples of Association Areas
sensory association areas
visual association areas
auditory association areas
general interpretation area: integrates all incoming signals into a single thought
prefrontal cortex: most complicated part of brain – intellect and complex learning (abstract ideas, judgment, reasoning)

13. Cerebral White Matter
functions to provide communication between cerebral areas
also provides communication between cerebrum and the rest of the brain

14. Brain Disorders (some examples)
Parkinson’s Disease
deficiency of the neurotransmitter dopamine
Epilepsy
sudden burst of irregular electrical activity in brain – can lead to seizures, convulsions
Stroke
blood clot in brain – paralysis appears on side of body opposite to side of brain affected
Alzheimer’s Disease
part of cortex shrinks, neurons lost
results in dementia, memory loss, disorientation, loss of body function