process of synaptic transmission +neurotrasnmitters,excitation,inhibition

What is a key concept about neurons in synaptic transmission n

Neurons dont touch each other

Electrical message will not cross synapse as gap acts as a break in circuit

How is the message sent

Neurotransmitters released from vesicles and diffuses across synapse between 2 neurons

Presynaptic neuron release these

Once reach other side - bind to receptors on dendrite of postsynaptic neuron

If neuron gets enough excitation from n.t like dopamine attaching to its dendrites - action potential triggered - excitation passes a threshold and sends message of excitation along whole cell

What HAPPENS after message is sent on

The nt are released by receptor and re absorbed by presynpatic neuron

What is seretonin an example of

Inhibitory nt

Blocks negative impulses

What is an example of excitatory nt

Neroadrenaline

When neuron is not sending a signal what is it described as and why

Rest (inside s negatively charged relative to outside)

Higher conc of NA outside

What happens when neurons receive a go message from excitatory nt?

Gates in cell wall open and NA enters

Increases postoperative charge inside neuron

What happens when enough sodium has entered neuron

Threshold is passed and neuron fires

Action potential travels down axon - jumping from node ranvier to node ranvier

What does action potential trigger

Trigger vesicles in axon terminal to move to cell wall and rupture - release nt into next synapse

Nt bind to receptors on dendrites - cause excitatory effect or an inhibitory

If enough excitatory effect - new action potential

What is the term used to describe how action potentials cant be stopped

Ballisitic

What does excitation in a neuron mean

Increased in electrical activity

More likely to start action potential

Noradrenaline is e.g (cause next neuron to increase in excitation)

What does inhibition mean

Decreases in its electrical activity

Less likely to start action potential

Inhibitory nt - cause next neuron to become more inhibited

E.g seretonin

What is dopamine an example of

Both excitatory and inhibitory

What is summation

Process of adding things together

One neuron gets lots of presynaptic Nuerons firing at it (excitatory/inhibitory)

If excitatory input outweigh the inhibitory input - makes postysanptic neuron fire which triggers a new action potential

What are the 2 types of summation

Temporal - same presynaptic neuron fires at post until it becomes greater (fires repeatedly)

Spatial - multiple psn fir at same post s.n at moderate level but together they add up to enough excitation to trigger post s.n to fire