The Cell Body. Contains nucleus and most organelles
These are the long slender threads that protrude from the soma. This is the reception area for incoming information from the Axon Terminals of another neuron.
The long fiber that extends from the base of the soma to transmit electrical impulses called action potentials.
These are the alien fingers (with pods) that branch off of the Axon. They release neurotransmitters to the dendrites of the next neuron.
These are these are the pods at the end of the Axon Terminals where the exchange of neurotransmitters happens. This is the site of communication between the presynaptic neuron to the postsynaptic neuron and an effector organ
~Located throughout a neuron
~Open or close in response to ligand binding
Resting Membrane Potential
-70 mV ~When the neruron is at rest.
~The inside of the neuron is negative inside
and the outside is more positive.
~K+ can cross through the membrane easily.
Voltage gated channels:
Open or close in a response to change in the membrane potential.
~temp and pressure
~PNS to CNS
~CNS to PNS
~Fat dense cells which form meylination for
multiple axons and provide protection.
~form segments of myelin sheaths of numerous
neurons at once.
One schwann cell forms ONE myelin sheath that myelinates one section of an axon. Seperated by the Node of Ranvier
Resting Membrane Potential
Determines the equalibrium of potentials for sodium and potass
Determining Resting Membrane Potential
1. Ion concentration gradients
2. Membrane permeability
3. Ion Channels
Potassium Equalibrium Potential
~As potassium diffuses outof the cell the
inside of the cell becomes more negative.
~Eletrical driving force "pulls" potassium into
the cell until equalibrium equals -94 mV.
~These driving forces are opposite in direction
and equal in magnitude.
~As sodium diffuses into the cell the inside becomes less negative (positive).
~eletrical driving force "Push" sodium outside of the cell.
~Equalibrium is +60mV
Resting membrane potential of neurons is permeable to both sodium and potassium however, it is 25% more permeable to ______?
At resting membrane potential, the iside of the cell has more...
potassium and organic anions
At resting membrane potential, the outside of the cell has more...
Sodium and Chloride
Sodium going into the cell creates a more______ charge
Potassium moving outside the cell creates a more ___________ charge.
What is Absolute Refractory Period
the period immediately following the firing of a nuron when it cannot be stimulated no matter how great a stimulus is applied.
The time when an action potential is below
a change in a cell's membrane potential that makes it more negative
the amount of time it takes for an excitable membrane to be ready for a second stimulus
The return to resting membrane potential
a change in a cell's membrane potential, making it more positive
the point at which sodium ions start to move into the cell (instead of out of the cell) to bring about the membrane depoloarization
Muscle or gland
two neurons linked together by gap junctions finctions in nervous system
most of sensations and motor signals are carried via chemical synapse.
Neuron to Neuron or Neuron to Muscle
where synapse occours.
From axon to presynaptic neuron
synapse to soma
presynaptic synapses to axon of post synaptic neuron
post synaptic potentials
a change in the charge on the membrane of the post synaptic cell
what are the two types of post synaptic potential?
Excitatory and inhibatory
excitatory post synaptic potential
makes the cell more likely to depolarize. They Hypopolarize to less negative.
inhibatory post synaptic signals
less likely to produce a potential. hypopolarzation (more negative).
one nuron to multiple
multiple nurons signal to one nuron
Grand Postsybnaptic Potential GPSP
addition of all effects of the ISP & ESP
the sum of all their signals on one cell
what are the 2 types of sumation?
Temporal and Spatial
one synapse fires rapidly onto the next nuron
lots of different synapses occouring all at the same time and in close proximity
a potential that does not reach threshold
does not increase