larger diameter nerve fibres have less resistance facing ion flow and so they are able to conduct at a much faster pace than smaller diameter nerve fibres

muscle spindles are present within the muscle fibres and they detect the amount of stretch occuring in a muscle they can be activated during the myotatic reflex which is described below.

golgi-tendon organs are parralell to muscles (not within but running alongside) their function is to detect the muscle ‘tone’ within the muscle so basically to detect how much tension there is within the muscle. it is present in the inverse myotatic reflex, which is described below.