introduction Flashcards
Anatomy of neurons
Cell membrane dendrites axon hillock axon meyelin nodes of ranvier buttons synapses
What is the resting potential inside a neuron
-70mv
Ions A- protein inside Na+ outside K+ inside Cl- Outside
semi permeable
the neuronal membrane is semi- permeable
what are the forces which determine distribution of ion
- diffusion
2. Electrostatic pressure
sodium potassium pump
keep sodium out.
Transports sodium out ans potassium in
There are three NA for every two K
- Requires energy from ATP
Moving information from one neuron to another:
Neurotransmission
Neurotransmitters activate receptors on dendrites
opens ion channels
ion cross membrane changing the membrane potential
If the potential felt at the axon hillock is big enough an action potential is triggered
ionotropic receptor
Fast acting, do not require a 2nd messenger
acetylcholine (Ach)
Glutamate
GABA
metabotrophic receptor
Acts on a g protein which in turn opens channel
dopamine
noradrenaline
serotonin
EPSP excitatory post synaptic potential
Depolarize cell membrane
- glutamate
IPSP inhibitory post synaptic potential
Hyperpolarize cell membrane
- GABA
Spatial summation
when several EPSPs arrive at the axon hillock simultaneously
Temporal summation
PSPs arrive in rapid succession can be summed
The action potential
All or nothing
Refractory period
propogation of the action potential
Depolarization of each segment of the neuron
- myelination greatly speeds up axonal transmittion = saltatory conduction
synaptic transmission
information processing
