1. Nervous System Notes
The nervous system is defined as the biological information highway that is responsible for controlling all biological processes, movement in the body and receives information via chemical signals.

2. Important Vocabulary
Stimulus: any change in the internal or external environment that causes a response
For example– slamming book on desk, hot/cold outside
Response: change in behavior or function by an organism after being exposed to a stimulus

3. Important Vocabulary Receptor: tissues specialized to detect stimuli
For example-sensory organs (eyes, ear, antennae) and are usually stimulated by taste, touch, smell
Effector: cell organelles, tissues or organs that produce responses to stimuli
For example– cilia, muscles

4. Example: If a volleyball is coming toward you
The stimulus is the volleyball coming toward you
The response is to move/try to catch/avoid
The effectors are the muscles used to respond!

5. What is a Neuron?
The functional unit— the nerve cell specifically adapted for transmission of an impulse
Nerves: simply a bundle of neurons— insulated from one another and each carrying individual impulses

6. Types of Neurons
1. Sensory– Transmit impulses from receptors to the brain and spinal cord
Include eyes, ears, tongue, nose, and skin
2. Motor- transmit impulses from central nervous system to effectors
3. Interneuron– relay nerve impulses between sensory and motor neurons

7. The Central Nervous System Brain and Spinal Cord

8. The Brain Facts: Is part of the central nervous system
 Only about 3 pounds and is 85% water!!!
 Contains more than 100 BILLION nerve cells
 Located in the cranium—protection

9. Cerebrum
voluntary activities
sensory areas—receives and interprets data from your skin, eyes, ear, tongue, etc.
memory, learning, thought, habits (even the bad ones)

10. Cerebellum walking, running, throwing, writing balance
coordination of motor activities
walking, running, throwing, writing
balance

11. Medulla breathing heartbeat coughing sneezing
* controls involuntary activities for example
breathing
heartbeat
coughing
sneezing

12. Central Nervous System
Z - Cerebrum
Y - Cerebellum
W - Medulla
X – Spinal Cord

13. The Parts of the Brain

14. The spinal cord coordinated activities between the brain and other body functions. The spinal cord is also the center for reflex reactions.
Reflex examples:
knee jerk,
blinking
flinching
coughing/sneezing
dilation of pupils

15. Reflex arc
A reflex is an inborn, automatic, involuntary response to stimuli
Reflex arc : a pathway over which nerve impulses travel in a reflex.

16. Receptor
Effector

17. Central
Consists of the brain,
and the spinal cord
Function is to relay
messages and process
information

18. associated cells that are not part of the brain or spinal cord
Peripheral
Consists of nerves and
associated cells that are not part of the brain or spinal cord
Divided into the sensory and motor neurons
Motor– impulses from CNS to muscles or glands
Sensory– impulses from senses to CNS

20. Malfunctions 1. Cerebral Palsy: disturbance of motor functions
2. Meningitis– inflammation of meninges of the brain/spinal cord

21. Malfunctions
3. Stroke– Cerebral hemorrhage– robs brain of oxygen due to a blood clot
4. Polio– viral disease that
affects the brain and NS

22. Malfunctions
5. Encephalitis– inflammation of the brain