Neuronal Cell Physio/Pain Flashcards
Where is Sodium in relation to the neuron?
Outside
Potassium is more on the __________ (inside/outside) of the neuron
Inside
The concentration force of potassium is _____________ (inward/outward)
Outward
The concentration force of both Na and Cl is ______________ (inward/outward)
inward
The Voltage force of Cl is _____________
Outward
Which ions have an inward voltage force ?
K and Na
List the steps of the Action Potential
- Stimulus overpasses threshold
- Depolarization
- Action potential
- Repolarization
- Hyperpolarization (RFP)
- Back to resting state
Describe Na ion movement during action potential
Sodium activation and depolarization is rapid
Describe K ion movement during action potential
Slow diffusion out of the cell
How does repolarization occur during an action potential?
By Na being inactivated and the slow diffusion out of the cell by K
Define a Neurotransmitter
Substance released synaptically by one neuron to an effector
What defines a neurotransmitter from a hormone
NT produce a localized effect as opposed to hormones producing systemic effects
Who termed the word synapse
Sir Charles Sherrington
Based on method of impulse conduction, list the 2 types of synapses
- Electrical
- Chemical
Define electrical synapse
Direct conduction through connexons; bidirectional
A unidirectional synapse where an unbridged junction is present and a chemical transmitter diffuses across a synaptic cleft between cells is:
Chemical synapse
What can be observed if looking through an electron microscope in a synapse?
Post synaptic density
What is the 1st step in NT release?
Action potential arrival opens voltage gated Ca2+ channels in Pre Synaptic terminal
In NT release, what activates docking proteins?
Calcium influx
What fuses to the pre synaptic membrane ?
Synaptic vessels
What occurs after the NT diffuses into the synaptic cleft?
Activates pre and post synaptic receptors
Describe how is NT action terminated
- enzymes in the cleft
- diffusion
- reuptake
What transportation mechanism is used for NT release?
Exocytosis
Which CNS associated cell can also be activated in response to NT releases from pre synaptic terminal that lead to increased in CA ions?
Astrocyte receptors
Give an example of a substance released by Astrocytes in response to a Calcium influx
ATP
Proteins
Describe astrocyte-released ATP function in neuronal activity
Can be inhibitory or excitatory
Synapse formation can be controlled by?
Astrocyte-released proteins
Describe what can happen with astrocyte-released proteins
Regulate pre synaptic function
Modulate post synaptic neuron response to NT
Based on conductance of postsynaptic membrane to selective ions, list the synapse classifications
Excitatory and inhibitory
An ___________ synapse is defined in an increase in post synaptic membrane conductance to sodium (depolarizes membrane)
Excitatory
Which ion conductance characterizes the inhibitory synapse, which in turn hyperpolarizes membrane?
Potassium/chloride
The main excitatory NT is _____________
Glutamate