Proprioception - masticatory feedback Flashcards
what is proprioception?
awareness of position of body parts in relation to each other and surroundings
name the proprioceptors in mastication
muscle spindles and joint receptors (TMJ)
muscle spindles are are intrafusal fibres. what are these?
specialised muscles fibres in the body of extrafusal contractile muscle fibres
muscle spindles give information on what?
muscle length
muscle spindles are in jaw openers or closers?
only in jaw closers
- masseter
- temporalis
structure of a muscle spindle (intrafusal fibre)
End parts are ?
Central portion is ?
The afferents synapse directly onto the nerves that supply the ?? causing ?
contractile
stretchy
extrafusal fibres
contraction
what kind of nerve endings are the afferents in the end parts of intrafusal fibres?
secondary nerve endings
what kind of nerve endings are the afferents in the central portion of intrafusal fibres?
primary Annulo-spiral nerve endings
afferents in the end parts of intrafusal fibres are fast or slow adapting?
slow adapting
detects length of fibres
afferents in the central portion of intrafusal fibres are fast or slow adapting?
fast and slow adapting
detects the length of fibres and the speed of change of length
what type of efferent nerve is goes to intrafusal fibres?
Gamma motor neurone
what type of efferent nerve goes to extrafusal contractile fibres?
alpha motor neurone
what type of afferent nerve goes away from intrafusal fibres?
Aa afferents
muscle spindles
Cell bodies in ? and afferents synapse in ?
V mesencephalic nucleus
v motor nucleus
muscle spindles in action
Load compensation
