Nervous System Flashcards
Actionable potential generation stage 1
Stimulus recieved
Stage 2 ap
Stimulus changes voltage such that the threshold is met
Stage 3 ap
Opening of vlotge gated na changes
Stage 4 ap
Na moves into cell
Take 5. Ap
Inside of cell becomes more positive - depolarisation
Stage 6 ap
Change in voltage triggers opening f voltage gated potassium channels
Stage 7
K leaves cell
Tage 8
Inside the cell becomes more negative - repolarisation
Stage 9
Return to resting potential
Synaptic transmission
1 action potential arrives t pre synaptic knob depolarising at membrane and Ca ion channels open
2 influx of Ca2 cause sympathetic vessel fuse with membrane releasing neurotransmitter - acetylcholine int synaptic cleft
3 acetylcholine diffuses and binds to receptors on post synaptic membrane causing action potential
4 acetylcholinesterase breaks down acteylchline in the cleft
Spatial summation
Action potential from multiple pre synaptic neurones are added together in post synaptic neurone
Temporal summation
Multiple action potential from a single pre synaptic neurone are added together in a post synaptic neurone over time
Neuromuscular junction
1 when AP reaches junction, Ca channels open causing Ca to diffuse into neurone
2 synaptic vessels to fuse withe presynaptic membrane and release acetylcholine into the synapse
3 it diffuses across synapse ad binds with receptors on membrane opening Na channels
4 muscle fibres depolarisation causes action potential and muscle ontactions
5 acetlycholinesterase breaks down acetylcholine
Sympathetic nervous system
Flight or fight
Increase heart rate
Dilate pupils
Bronchodilator
Reduced blood flow to peripheral skin
Stimulates sweat glands
Parasympathetic nervous system
Decrease heart rate constrict pupils
Broncoconstriction - constrict airflow
Increased blood flow to gut and salivary glands
Increased stimulation - movement of intestines
