Chapter 3–Biological Bases of Behavior
← Structure of Neurons
• The cells that receive, integrate and transmit information
← 1. Incoming message first received by dendrites
← 2. Into the Soma (the cell body), containing the cell nucleus.
← 3. To Axon (long thin fiber) toward another neuron
← 4. Axon covered by myelin sheath = insulation for protection (from adjacent
• Made up of glia cells (carry nourishment to and waste away from the
neuron cells) • Its functions are:
If it is damaged, there could be a loss of sensation, a loss of
coordination. It is also a reason that a baby is so uncoordinated
because the myelin sheath is not fully developed in the baby.
← 5. Message ends at synapse
• terminal button
• synaptic cleft
• receptor site of the next neuron
• Connection to the other neuron
3 ← Communication between Neurons
4 • When no information is being communicated we call it the “Resting
• When they are communicating, it comes out of rest. If the message is
sent, the neutrons create “Action Potential”.
• Permeability is changed so that positive ions flow in
Refractory period = down time required before another firing
All or none = neurons fire or not. Strength is communicated via
speed of firing.
← 6. The action potential arrives at the terminal button. Therefore, synaptic
vesicles release info (neurotransmitters)
• Only the right shaped message (neurotransmitter) can be received (lock
← 7. Buttonal Binding of N.T to receptor s“Post synaptic
potential” May do so in 2 ways
• Excitatory way = where the probability the neuron will fire is increased
• Inhibitory = the probability the neuron will fire is decreased
← What are they communicating?
6 ← The Nervous System
7 ← Examining the Brain
Somaatc Nervous AAutonomic Nervous
Syysem System SppnalCoord Brainn