1. Neural Communication

2. Neurons
Axon
Soma
Dendrite
Nucleus
Myelin Sheath
Synaptic knobs

3. How does it fire?
Neuron Dance

4. How does it fire?
Inhibitory and excitatory neurotransmitters stimulate the dendrite
Threshold (level of stimulation required to trigger an neural impulse) = -55 millivolts
 Firing the impulse (action potential, an electrical charge) down the axon
Exchange of positive ions & negative down the axon fibers to the next neuron

5. Synapse Axon terminal Synaptic gap Neurotransmitters Receptor sites
Reuptake - (when the sending neuron reabsorbs excess neurotransmitter molecules
Drugs: mimic neurotransmitters
Agonists – excite & cause neurons to fire
Antagonists - inhibit

6. Acetylcholine (Ach) – muscle movement & memory
Lack of Ach can result in paralysis or memory loss
Dopamine – Control of bodily movements, the “feel good neurotransmitter”
Lack  Parkinson’s disease
Endorphins – pain relief and sense of well being, released during periods of pain or intense exercise  “runner’s high”

7. Serotonin - regulation of learning, mood, sleep
Levels drop in winter  Seasonal affective disorder
Many anti-depressants work to prevent reuptake of excess serotonin so it continues to affect the receiving neurons

8. Drugs vs. Neurotransmitters

9. Example - Cocaine Interferes with Dopamine transporters
Cocaine blocks reuptake --> overstimulation of the post-synaptic neuron in reward pathways
Agonist to dopamine

10. Neurotransmitters & drugs
Type in the above web address or click the link.
Are the drugs agonists or antagonists? Both?

11. Afferent –Sensory Interneurons Efferent - Motor

12. Peripheral nervous system (PNS) - all nerves and neurons that that run through the body itself
Somatic nervous system - nerves that carry information from the senses to the CNS and from the CNS to the voluntary muscles of the body.
Autonomic nervous system - nerves that carry information to all of the involuntary muscles, organs, from the CNS     
Sympathetic division (fight-or-flight system) - part of the ANS responsible for reacting to stressful events and bodily arousal (excite)
Parasympathetic division - part of the ANS that restores the body to normal functioning after arousal and is responsible for the day-to-day functioning of the organs and glands (slow back down)

13. The Endocrine System
Glands - secrete chemicals into bloodstream - help control bodily functioning
- Hormones: chemical substances released by the glands
(30 different)
- Hypothalamus: controls eating, linked to emotion & reward center, controls the endocrine system.
- Pituitary Gland: “Master Gland” – regulates growth and controls other glands

14. The Endocrine System
The Endocrine System is the body’s “slow” chemical communication system. Communication is carried out by hormones synthesized by a set of glands.
OBJECTIVE 10| Describe the nature and functions of the endocrine system and its interaction with the nervous system.

15. Images of the Brain PET Scan-
examines brain function and chemical activity
CT Scan-
Computer enhanced topography/ x-ray of structures
MRI Scan-
uses magnetic fields, radio waves, computers to map brain structures

17. Brain mobile time!