<prompt> All are true regarding intrafusal fibers exceptNuclear chain fibers are shorter thinnerNuclear bag fibers are lesserPrimary endings excited by bag fibers onlySecondary endings excited by chain fibers only  <response>: Nuclear bag fibers are thicker, longer and fewer in numbers. They have a bag or bulge in the centre where the afferent fibers received are Aα type with the primary ending Annulospiral. The efferent fibers are Aγ1, which are dynamic fibers with plate ending.Nuclear chain fibers are thinner, shorter and more in numbers. They do not have a bulge, but receives afferent fibers of type Aα with the primary ending Annulospiral. The peripheral part also receives afferent fibers of type Aβ with the second ending Flower spray. The efferent fibers are Aγ2 static fibers with trail ending. 