PSY 1010 Lecture Notes - Lecture 3: Synaptic Vesicle, Myelin, Action Potential
1 May 2018
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PSY 1010 Exam 1 Notes Allyssa Leaton
Chapter 3 – The Biological Bases of Behavior
• If we were to unfold a human brain, exposing all of its surface area, it would be about the size of a large
pillowcase
• Overview of the Neuron
o Neuron: cells that receive, integrate, and transmit information; vary in size and shape
▪ Generate electricity that create action potentials (nerve impulses)
▪ Synthesize, store, and release neurotransmitters
o 3 major types of neurons:
▪ Interneurons: majority of neurons, signals between the CNS and PNS
▪ Sensory neuron: signals from the PNS to the CNS
▪ Motor neuron: signals from the CNS to the PNS
o Parts of the Neuron
▪ Soma: the cell body of the neuron, contains the nucleus
▪ Dendrites: extensions from the soma that receive information from other cells, usually in
the form of neurotransmitters binding to the receptor site
▪ Axon: the structure that transmits a nerve impulse
▪ Myelin sheath: insulates the axon, increases the speed and efficiency of the action potential
by jumping from each Node of Ranvier
▪ Terminal buttons: knob-like structures that secrete neurotransmitters into and across the
synaptic cleft
▪ Synapse/ Synaptic Cleft: the junction where neurotransmitters release into and ultimately
bind to a neighboring dendrite
▪ Synaptic vesicle: houses neurotransmitters, eventually releasing them into synaptic cleft
• The Neuron at Rest
o Resting state = resting potential
o As the sodium and potassium channels are opened (going in) and closed (going out), it creates an
action potential
• Postsynaptic Potentials and Reuptake
1. Synthesis and storage of neurotransmitter molecules in synaptic vesicles
2. Release of neurotransmitter molecule into synaptic cleft
3. Binding of neurotransmitters at receptor sites on postsynaptic membrane
4. Inactivation (by enzymes) or removal (drifting away) of neurotransmitters
5. Reuptake of neurotransmitters sponged up by the presynaptic neuron
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