AP. Psychology
Neural Transmission
Name:____________________________________________________ Date:______________ Period:______
Label the diagram
A. Vesicle
B. Synapse, synaptic cleft,
synaptic gap
C. Receptor site, receptor cell,
receptor
D. Neurotransmitter
X. Sending neuron, axon terminal,
terminal branch, axon button
Y. Receiving neuron, dendrite
What might be happening at E? (hint
SSRIs) Agonist The drug is blocking
reuptake
Explain the steps of a neural impulse
1.
Polarization (Resting potential) The neuron’s axon is at "rest" , more positively charged are on the outside and negatively
charged on the inside
2.
Depolarization (Action potential) Stimulation from excitatory neurotransmitters cause an impulse to be sent out from a cell
body. When this happens sodium channels open and the positive sodium cells surge into the cell. Once the cell reaches a
certain threshold, an action potential will fire, sending an electrical signal down the axon. Action potentials either happen or
they don't; there is no such thing as a "partial" firing of a neuron. This principle is known as the all-or-none law.
3.
Repolarization/Hyperpolarization Repolarization results from the movement of positively charged ions out of the cell.
The repolarization phase of an action potential initially results in hyperpolarization, a time when the membrane is more
negative than the resting potential.
4.
Refractory Period (things return to normal) After the neuron has fired, there is a refractory period in which another action
potential is not possible. During this time, the potassium channels reopen and the sodium channels close, gradually returning
the neuron to its resting potential. Once the neuron has returned to the resting potential, it is possible for another action
potential to occur and transmit the signal down the length of the axon.
Explain how neurons communicate.
5.
Vesicle opens At the synaptic terminal (the presynaptic ending), an electrical impulse will trigger the migration of vesicles
containing neurotransmitters toward the presynaptic membrane. The vesicle membrane will fuse with the presynaptic
membrane releasing the neurotransmitters into the synaptic cleft.
6.
Receptors The neurotransmitter molecules then diffuse across the synaptic cleft where they can bind with receptor sites on
the postsynaptic ending to influence the electrical response in the postsynaptic neuron.
7.
Excitation or inhibition Excitatory neurotransmitters stimulate the receiving neuron whereas inhibitory neurotransmitters
balance the excessive simulations without stimulating the brain.
8.
Reuptake After the neurotransmitter has performed its function it is reabsorbed by the sending neuron. Reuptake is important
because it allows for the recycling of neurotransmitters and regulates the level of neurotransmitters present in the synapse,
controlling how long the signal from the sending neuron lasts
Draw and label the parts of a neuron.