Chemico-electrical synapse

G protein coupled synapse

Discrete synapse

2nd messenger synapse

Diffuse synapse

Use ACh but acting on different GPCRs

Use NA but acting on different GPCRs

Use the same GPCR

Use ACh but acting on the same GPCRs

Use different neurotransmitters acting on different GPCRs

Signalling involves class pre-ganglionic B neurons forming diffuse synapses on post-ganglionic neurons

The Sympathetic division of the ANS uses ACh and the Parasympathetic division uses Noradrenaline as the transmitter

A class A neuron contacts a class C post-ganglionic neuron

Signalling involves nicotinic ACh receptors

Signalling between neurons involves the use of varicosities

Beta adrenaline

Only nicotinic ACh

ACh or NA

Only muscarinic ACh

Only ACh

Always has preganglionic neurons to skeletal muscle and postganglionic neurons to all internal organs

Has preganglionic neurons to smooth muscle and postganglionic neurons to other target tissues

Sometimes has preganglionic neurons to skeletal muscle and postganglionic neurons to all internal organs

Always has preganglionic neurons and postganglionic neurons from CNS to all target tissues

Always has preganglionic neurons to the CNS and postganglionic neurons to the internal organs

different motor units to the one muscle are activated at different times

all the motor units to the one muscle are activated at the one time for maximum force

motor units to agonist and synergistic muscles are activated at different times

motor units to the one muscle are activated in the size principle order

motor units to agonist muscle are activated at different times from those to antagonist muscles

it allows small motor units to be activated first and the more energy-demanding large ones to be activated last

it reduces the amount of ATP required within the sarcomeres of the muscle to maintain force

it allows the muscle to maintain a constant amount of force

it allows the strenghth of muscle contraction to be graded to the load to be lifted

it ensures that the muscle is kept at the optimal length for maximum overlap of myosin and actin filaments