Transcript Neurons

Neurons
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Structure and Communication
Neurons:
Structure and Communication
The Nervous System
• Coordinates bodies
activities by detecting
stimuli and directing
body’s responses
• CNS: central nervous
system
– Brain and spinal cord
– Processing input
• PNS: peripheral nervous
system
– Tissue outside of CNS
– Delivers info to/from CNS
+ other organs through
nerves
Shape and Function of Neurons
• Neuron: nerve cell
• Designed to receive info, react to it, and send messages.
• Transmit signals over long distances
Shape and Function
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Cell shape: long arms (you should already have this in handout)
Dendrites: receives messages
Body: processes info
Axon: sends messages
Myelin Sheath: enables signals to “jump” from node to node
– 150m/s; spinal cord to toes in less than 7 milliseconds
Let the communication begin!
Two Types of Neurons
• Sensory neurons: carry info of stimuli to
CNS
– Boiling water
• Motor Neurons: carry signals away from
CNS
– Remove hand from water
• Crossing the Divide
The Reward Pathway
• Reflexes
– Hand on hot stove
– Nervous system allows coordinated and proper
response to sensory input
• Feeling Good!
• Function in Survival
– I’m hungry--> I eat--> I feel good
– Thirsty --> drink --> feel good
– Going to bathroom, vomiting, etc.
• All pathways depend on PROPERLY
FUNCTIONING CELLS!
– Neurotransmitters, # of receptors, etc.
Drugs Alter the Reward Pathway
• Changes proper
function of cells in the
pathway
• Mostly in synapse
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– Alters # of receptors
– Function of reuptake
pump
– Some changes are
permanent
• My college buddy,
Mitch
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