When is a neuron more positive outside and more negative inside?
When the neuron is resting (nonconducting).
What are three reasons why there is more positive outside and more negative inside?
1. The distribution of different ions across the membrane. 2. The outside of the neuron at rest has more positive sodium ions present. 3. The inside of the neuron at rest has more negative ions and large negatively charged proteins.
What does a neuron's chemical and physical environment influence?
It influences both the impulse conduction and synaptic transmission.
What are neuronal pools?
Neurons in the Central Nervous System that are organized into dendrite patterns.
Are all neuronal pools the same?
No, each pool differs from all others and has its own role in regulating homeostasis.
How many neurons can a single neuronal pool contain?
Thousands to millions of neurons.
How are neuronal pools organized?
After how long does the neuronal cell body lose its mitotic apparatus?
Around 6 months of age
After the neuronal cell body loses its mitotic apparatus, can it divide?
No, after the neuronal cell body loses its mitotic apparatus it is no longer able to divide.
What happens if a neuron is damaged?
It is either permanently lost or in some types of neurons it can be repaired.
In what nervous system is a myelinated axon or dendrite more likely to be repaired in?
In the Peripheral Nervous System
What needs to be intact in order for the myelinated neuron to be repaired?
The cell body. -Damage to myelinated axons and dendrites may be repaired if the cell body remains intact.
What is the cell that must remain active during the repair of damaged myelinated axons or dendrites
The Schwann cells that perform the myelination must remain active in order to help repair the damaged neuron.
What is Wallerian degeneration?
Degeneration of the distal portion of the neuronal process and myelin sheath.
In what nervous system is damage to a neuron usually permanent?
In the Central Nervous System damage to a neuron is usually permanent.
What are the steps to repair a damage neuron?
1. Wallerian Degeneration -Degeneration of the distal portion of the neuronal process and myelin sheath 2. Macrophages phagocytize the remains 3. The Schwann cells for a tube that appears to aid regeneration by directing the regrowing nerve fiber.
What does the Schwann cells do in order to aid in repair of damaged neurons?
Schwann cells make a tube that appears to aid in regeneration by directing the regrowing nerve fiber.