Lecture 4 Notes
Aside: Healthy student Initiative:
The Biological Basis of Behavior
Communications become comprehendible when they are in a form of a pattern. For example,
when someone is talking their voice makes vibrations. Each vibration by itself may provide little
information but all the vibrations together from meaningful patterns of the information. So it is
with the nervous system.
Types of Cells within the Nervous system
- Nervous system handles information
Nervous tissue consists of two types of cells:
Glia Cells: provides structural support and insulation for neurons
Neurons: Individual cells in the nervous system that receive, integrate, and transmit
Most neurons communicate among themselves but a small minority receives signals from outside .
The structure of the nervous system
Dendrites: send information to the soma. Some dendrites stimulate the soma to fire and some
try to do the opposite.
Axon – sends information (electrical impulse) away from soma onto other neurons The Neural Impulse
Neuron is ready to release a electrochemical reaction (at rest is like a tiny battery)
Resting Potential: A stable, negative charge when the cell is inactive
Action Potential: a very brief shift in a neurons’ electrical charge that travels along an axon.
Absolute refractory period: the minimum length of time after an action potential during which
another action potential cannot begin
The Synapse: space between two neurons
Synaptic cleft: singals have to jump this gap
Neurotransmitters: travel from synaptic vesicles (within the buttons) to receptor sites “tuned”
to recognize and respond to specific neurotransmitter.
When this happens can lead to a postsynaptic potential (PSP): a voltage change on a
postsynaptic cell membrane
This is NOT all-or-none but is graded and increases or decreases the PROBABILITY of a neural
impulse in the receiving cell.
Two kinds of