1. EQ: How does our nervous system control the functions within our body?
The Nervous System
EQ: How does our nervous system control the functions within our body?

2. Functions of the Nervous System
Control center for all body activities
Responds and adapts to stimuli
(Ex: pain, temperature, pregnancy)
Stimulus (stimuli): a thing or event that evokes a specific functional reaction in an organ or tissue

3. Neurons
Neurons : microscopic nerve cells that make up the brain, spinal cord, and nerves
- 30,000 neurons can fit on a pinhead

4. Communication Between Neurons
Neurons send messages from one to another through the body
This is how our body responds to signals we receive.

5. Sensory Receptors
Sensory Receptors: neurons specialized for receiving specific kinds of stimuli – send the messages to the brain
Mechanoreceptors respond to physical force such as pressure (touch or blood pressure) and stretch.
Photoreceptors respond to light.
Thermoreceptors respond to temperature changes.
Chemoreceptors respond to dissolved chemicals (ex: taste, smell, changes in body chemistry)
Nociceptors respond to pain

7. Memory
Memories are formed as you receive stimuli from your different receptors.
A memory is not a snapshot stored in the brain – it must be put together from information stored in various parts of the brain.

8. Two Major Divisions of the Nervous System

9. Central Nervous System
Brain : a mass of 100 billion neurons located inside the skull
-Learning occurs as more connections or stronger connections are made between neurons

10. Anatomy of the Brain Cerebrum : largest part of human brain
- Responsible for:
- Thought
- Language
- Senses
- Memory
- Voluntary movement

11. Anatomy of the Brain Cerebellum : at base of brain -Responsible for:
- Muscle coordination
- Balance
- Posture

12. Anatomy of the Brain Brain Stem : connects brain to spinal cord
-Responsible for:
- Breathing
- Swallowing
- Heartbeat
- Blood pressure

13. Central Nervous System
Spinal Cord : Column of nerves from brain to tailbone – protected by vertebrae of spine
Responsible for:
- Sending messages between the brain and the rest of the body
*Impulses may travel as fast at 268 miles/hr

14. Nerve Responsibilities
- Sensory nerves - carry messages from body to brain (pain, pressure, temperature) - Motor nerves – carry messages from brain to body to respond

16. The Learning Brain Video

17. Problems of the Nervous System
Concussion
A temporary disturbance of the brain’s ability to function due to a hard blow to the head

18. Alzheimer’s Disease
A gradual shrinking of the neurons in the cerebrum
Symptoms: memory loss, emotional disturbances, inability to function on own, death

19. Epilepsy
Abnormal transmission of messages between the neurons in the brain
Symptoms: seizures

20. Drugs = neuron death