Topic 1 Flashcards
(62 cards)
Neuron
electrically excitable cell that receives, processes, and transmits information through electrical and chemical signals
unipolar neuron
cell body with a nucleus and a projection (neurite) that is either an axon or a dendrite or both ⇒ has a specialized structure at the end
Pseudo bipolar (Pseudo unipolar) neuron
cell body that has an initial segment branching into 2 different directions
bipolar neuron
has a cell body with 2 very distinct processes that go in different directions
multipolar neuron
has the cell body with one end on of a specialized structure (dendrites) and then another longer process (axon)
Axosomatic
When it synapses on the soma ⇒ less likely to trigger an action potential
Axosomatic properties
inhibitory and strongly impacting (shunting) of post synaptic potential near the trigger zone
Axodendritic
presynaptic neurons synapse on the dendrites
Axodendritic properties
- excitatory with sub cellular targets
- shaft (between soma and dendrite projection tip)
spine (on the shaft of the dendrite and is a specialized projection)
Axo-axonic neurons
presynaptic cell synapses on the axon which has no impact of response from the cell body (excitatory/inhibitory)
Axo-axonic properties
modulatory and have no direct effect on the trigger zone (downstream)
- Controls the amount of NT released
- Presynaptic excitation or inhibition is not affected but can modulate the signal as it travels down the axon to make it stronger or weaker by opening or closing channels at the axon channel
projection neuron
dendrites and cell body in one region, axon projects to and synapses in another region
local interneuron
project in the same region instead of a different region ⇒ can be excitatory or inhibitory
efferent
exiting from ⇒ such as going from CNS to periphery
afferent
going to ⇒ such as periphery to CNS
T/F both projection neurons and interneurons can be excitatory and inhibitory
true
excitatory vs inhibitory
- Excitatory: will increase activity of a neuron on which it synapses
- Inhibitory: will reduce activity of a neuron on which it synapses
concentration gradient
the inside and outside of the neuron have different salt concentrations
electrical gradients (voltage)
salt ions have charge and can generate gradients
- Na+, K+, Ca2+, Cl-
transmembrane voltage
the recording electrode measures the difference in charge
- To generate voltage requires 2 chambers separated by an insulator (such as a membrane)
polarized
in most neurons, the inside is more negative than the outside
membrane potential
the charge inside vs outside (not outside vs inside)
- the membrane potential is not the action potential but instead is the steady state potential of the membrane when it isn’t receiving information
- the membrane acts as the insulator and barrier between the outside and inside of the cell to generate the potential difference
most neurons have a resting membrane potential of what?
-40 to -80 mV
how is membrane potential generated?
by the differential distribution of ions across the cell membrane
- The pumps are housekeeping proteins which make sure the appropriate concentration of ions are present inside and outside of the cell