How does neuron communication work?
A chemical signal is recived at the psot synapitic cell dendrites. that chemcial signal produces an e;ectrical current thatr spreads to the soma
when does the neuron fire an action potential
if enough current accumulates at the axon hillock
what happens when it reaches the presynaptic cell axon termianl
it releases neurotransmitters
what is the traveling down the axon towards the end of the neuron know as
propogation
what are Neurotransmitters
they are ligands, they are molecu;es that are going to bond to other molecules
whats a motor neuron
starts in the spinal cord and goes to the muscles, its axon terminal is coming clolser to a muscle
What is a sensory neuron
a receptor
where is the soma of a sensory neuron
The soma of the sensory neuron is in the middle instead of the one end and the axon is split into two
Resting Membrane potential
Typically -70 mV There are more negative charges inside than there are outside, that’s what makes it negative. In other words the membrane is polarized
Maintained by ion pumps.
Involves sodium (Na+), potassium (K+), calcium (Ca2+) dynamics
whjat is the sodium posstauim pump
a protein. It puts sodium out and potassium in. There’s more calcium on the outside because there is also a calcium pump.
what does the calcium pump do
puts calcium outside
Large anions
(negatively charged ions) and are protens that are way to big to go anywhere
whatg are the action potwntial stages
1 Depolarization – If you add positive charge inside the neuron
2 Threshold reaching – if you shock it enough or add enough positive charge and an action potential will occur
3 Complete depolarization
4 Hyperpolarization – when things turn around and the neuron becomes less positively charged
5 Membrane potential restoration
whats the casue of depolarization and hypolarization
are due to ion channels (Na and K) opening and closing.
All sodium potassium channels are iin the nodes of ———-
Ranvier
what is the sesne of your body position
Proprioception
Neurotransmission process
1 Action potential arrives at axon terminal
2 Voltage-gated Ca2+ channels open
3 Ca2+ enters the presynaptic neuron
4 Ca2+ signals to neurotransmitter vesicles
5 Vesicles move to the membrane and dock,
6 Neurotransmitters released via exocytosis
7 Neurotransmitters bind to receptors
8 Signal initiated inthe postsynaptic cell
Fast Neurotransmitters
Gultamate and GABA. Glutamate makes it more liekly to fire the action potenial and GABA dosent
Slow neuron transmitters
Dopamine, Oxytocin, adrenaline, serotonin
what are the receptor categories
ionotropic receptors and metabotropic receptors
ionotropic Receptors
immediate ion channel activarion. they are fast and includ thier own ion channels
Metabrotropic Receptors
Signal transduction cascades. They are slow and link to ion channels or to the nucleus via signal transduction casades
Agonists
Activate receptors. They are drugs that bind to and activate the receptor to do whatever the receptor was going to do if the ligand bound to it.
Anatagonists
Block receptor activation. Are drugs that looks enough like the ligand that it can bind to the receptor but its not a good enough fit for the ligand to do what it needs to do. The antagonist is actually blocking from what the ligand needs to do.
