Please enable JavaScript.
Coggle requires JavaScript to display documents.
Peripheral Nervous system (Properties of synpases (Calcium channels (L…
Peripheral Nervous system
Somatic ("voluntary")
Sensory
Motor
Autonomic ("involuntary")
Sympathetic
Sensory
Motor
Parasympathetic
Sensory
Motor
Sensory = Afferent
In at DRG (dorsal root ganglion)
Motor = Efferent
Out at ventral root (first/upper)
Can be upper and lower motor neuron. Upper in CNS, lower is leaving
Cranial nerve = Out of brainstem
Spinal nerve = Out of spinal column
Conscious movement
CNS + PNS
Stimulus -> Brain -> Upper motor neuron -> Lower motor neuron
Segmental reflex
Sensory neuron -> Spinal cord -> Motor neuron(es) -> response
Neuron = Nerve cell
Nerve fibre = part of a neuron
Nerve = "trunking" bunches of axons + support cells
Cell body = soma / perikaryon
Plexus = Place where nerves come together
Collection of cell bodies = Ganglion (in peripheral), Nucleus (in brain)
Properties of neurones
Conduction velocity
Saltatory conduction / myelination
Myelin sheath
Schwaan cells / oligodendrocytes
Node (of Ranvier) to node
Thickness of nerve fibre
A fibres
A\( \delta \)
B fibres
C fibres
Temperature
Refractory period
Ensure mono-directional
Potassium channels open (hyperpolarisation)
Relative vs absolute
Absolute completely impossible (Na+ channels inactivated)
Types of neurones
Multipolar
Bipolar
Psueod-unipolar
Different fibre types also
Properties of synpases
Pre-synaptic terminal to post-synaptic terminal (synaptic cleft in between)
1) Influx of calcium ions
2) Neurotransmitter released by exocytosis from pre-synaptic membrane
3) Binds to receptors on post-synaptic terminal
Calcium channels
L-Type
Long action
N-type
Neither particularly long or short
T-Type
"Transient" (short acting)
More neurotransmitter arrives = Greater post-synaptic potential (if large enough reaches threshold to cause action potential)
Transmitter binds to receptor, alters pore diameter, ions can now move through
Temporal synaptic summation
Fires several times in relatively short succession
Allows threshold to reach as membrane potential 'stacked'
Neuromuscular junction
Endplate instead of post-synaptic terminal
Different compliment of ion channels
Action potential released Ca2+ into muscle