PSY100H1 Lecture Notes - Neuron, Frontal Lobe, Occipital Lobe
Components of the Neuron
Å Dendrites: receives information from other neurons
Å Cell body: creates transmitter molecules
Å Axon
Å Myelin part of axon that insulates the nerve cell, speeds up
conduction of nerve messages
Å terminal buttons of the axon release transmitter
Graded Potentials
-stimulation of the nerve membrane
can open ion channels in the
membrane
-NA+ ions flowing in will
depolarize the membrane
(from -70 mV to about -60mV)
-K+ ions flowing out of membrane
will hyperpolarize the membrane
(from -70mV to about -90mV)
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The Action Potential
-graded potential are generated at the dendrites and are conducted along the membrane to
the axon hillock
-if the summated activity at the axon hillock raises the membrane potential past threshold,
an action potential (AP) will occur
-during AP, NA+ ions flow into the cell raising the membrane potential to +40 mV, producing
the spike
-the restoration of the membrane potential to -70 mV is produced by an opening of
channels to K+
-the AP is conducted along the axon toward the terminals
Synaptic Functioning
-Neurotransmitters (NTs) are chemicals stored within vesicles of the presynaptic cell
-released in response to the action potential sweeping along the presynaptic membrane
-transmitter molecules diffuse across the synaptic cleft and bind to postsynaptic receptors
-receptor binding opens or closes ion channels
-NA channel opening: Depolarizes the membrane
-K+ channel opening: hyperpolarizes the membrane
-Neuromodulators: indirectly alter the activity of other transmitter substances
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PSY100H1 Full Course Notes
Verified Note
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Document Summary
myelin part of axon that insulates the nerve cell, speeds up conduction of nerve messages. terminal buttons of the axon release transmitter. Stimulation of the nerve membrane can open ion channels in the membrane. Na+ ions flowing in will depolarize the membrane (from -70 mv to about -60mv) K+ ions flowing out of membrane will hyperpolarize the membrane (from -70mv to about -90mv) www. notesolution. com. Graded potential are generated at the dendrites and are conducted along the membrane to the axon hillock. If the summated activity at the axon hillock raises the membrane potential past threshold, an action potential (ap) will occur. During ap, na+ ions flow into the cell raising the membrane potential to +40 mv, producing the spike. The restoration of the membrane potential to -70 mv is produced by an opening of channels to k+ The ap is conducted along the axon toward the terminals. Neurotransmitters (nts) are chemicals stored within vesicles of the presynaptic cell.
