1.
2 things determine speed of propagation: Unmyelinated=slow (8 m/s)
Myelinated= faster (100 m/s)
2.
Absolute Refractory Period: Stimulus of any intensity, can't generate another action potential.
3.
Are there any VG channels under schwaan cells?: No (only found in Nodes of Ranvier)
4.
Cable properties: Look at notes
Refer to a cell's ability to conduct electrical charges through its cytoplasm
5.
Can positive charges leak out through membrane?: Yes
6.
Chemical Synapse: Between neurons or neurons and effector cells (cell of gland or muscle)
7.
Electrical Synapse: Involve gap junctions (connection proteins)
Gap junctions found in cardiac muscle and between neurons in the brain
Look at notes
8.
Gaps of Schwaan cells on membrane: Nodes of Ranvier
9.
How are the charges of action potentials propagated down Axon spread?: Spread with decrements (further away from stimulus side, smaller the charge)
10.
Myelinated Axon: Enclosed with Schwaan Cells (act like insulation-prevent movement of ions through membrane)
11.
Reason for relative refractory: During Relative refractory period, K+ VG channels are open, causing repolarization.
K+ continues to leave the cell, making inside of cell more negative (causing hyperpolarization)
Stay open a little after repolarization, results in hyperpolarization.
While open in hyperpolarization, K+ is still leaving the cell, causing an effect opposite of a threshold stimulus (inside of cell more negative)
Threshold Stimulus=depolarization
12.
Relative Refractory: Some Na+ VG channels are inactivated, others are not
Takes a stronger stimulus than usual, but can stimulate another action potential
13.
Saltatory Locomotion: Seem to be hopping, but don't move anywhere.
Propagated action potentials --> 10x faster than unmyelinated
Max amount distance nodes can be apart (7mm)
14.
Synapse: A junction
Electrical and Chemical
15.
Voltmeter: Reads membrane potential across axon
