Jumping with Glia-l
Name one function of glial cells.
What is:
- Supporting and protecting neurons
- Speeding up nerve impulses
- Maintaining the environment around the neuron (keeping the neuron functioning)
- the nervous system's immune cells
The resting potential for a neuron
What is -70 mV
For every three blank ions transported out of the cell, two blank ions are exchanged and are transported into the cell.
What are Na+ (Sodium) and K+ (Potassium)?
Primary energy source for all living cells.
What is adenosine triphosphate (ATP)?
Schwann cells are found in this part of the nervous system.
What is the peripheral nervous system?
These glial cells produce the myelin sheath in the CNS.
What are oligodendrocytes?
The process of action potential "jumping" from myelinated segment to segment.
What is saltatory conduction?
This rule says that all action potentials of a neuron are the same. No action potential is bigger or smaller. It either happens or it doesn't.
What is the all-or-none law?
The main inhibitory transmitter in the CNS, calming everything down.
What is GABA (gamma-aminobutyric acid)?
These cells were described as being the "packing peanuts" of the nervous system.
What are glial cells?
These glial cells act as the "garbage men" of the nervous system.
Microglia (phagocytes)
Describe what membrane potential is.
What is the difference in electrical potential between the interior and the exterior of the cell, due to an unequal distribution of ions?
What is exocytosis?
The chemical messenger in the nervous system allowing muscle movement, memory, and more.
What is acetylcholine (ACh)?
Drugs can block these channels, stopping action potential from happening, disallowing you from either feeling sensation or movement (depending on the drug).
What are sodium channels?
These glial cells create the blood-brain barrier, acting as a filter to keep the bad chemicals out and let the good chemicals in
What are astrocytes?
When ion channels move from a high concentration gradient to a low concentration gradient.
What is diffusion?
Explain the difference between ionotropic receptors and metabotropic receptors.
Ionotropic: Acts quicky for short-effects. Change shape when bound to ligand (neurotransmitter), creating a channel allowing for ions to move through.
Metabotropic: (Usually) takes longer. Does not use ligand-gated ion channels. Activates a G-protein that in turn activates Secondary messanger that activates something else. May or may not open ion channel somewhere else in the membrane.
The death of this catecholamine neuron impairs movement and may cause tremors or stiffness, such as in Parkinson's.
What is dopamine?
This autoimmune disease affects the CNS, causing the immune system to think myelin is bacteria and attack it.
What is multiple sclerosis?
This process "eats cells," breaking down engulfed materials (such as bacteria, dead cells, or debris) to get rid of cellular waste.
What is phagocytosis?
Describe action potential in six steps.
1. Na+ channels open, Na+ begins to enter cell.
2. K+ channels open, K+ leaves cell.
3. Na+ channel becomes refractory, no more Na+ enters cell.
4. K+ continues to leave cell, causing membrane potential to return to resting level.
5. K+ channel closes, Na+ channel resets.
6. Extra K+ outside diffuses away.
Name the four steps of neurotransmission.
1. Synthesize. Transmitter substance imported in, synthesized by neurotransmitter and packed into vesicles.
2. Release. Action potential causes transmitter to be released across the membrane.
3. Receptor Action. Transmitter crosses synaptic cleft and binds to a receptor.
4. Inactivation. Transmitter either taken back into terminal or is inactivated in the synaptic cleft.
Describe how endorphines, enkephalines, and Substance P work together.
They all work together to regulate pain perception. Endorphins and enkephalins are natural pain killers, while Substance P signals pain.
Loss of this neurotransmitter causes significant cognitive losses, including in memory.
What is acetylcholine?