Muscle Spindles Flashcards
membrane potential at rest is _____. When it ______, it becomes 60-65
70mV,
depolarized
muscle stretch leads to…
- monosynaptic excitatory connection to homonymous muscle
- monosynaptic excitatory connection to synergists
reciprocal inhibition
disynaptic inhibitory connection to antagonists
the relaxation of muscles on one side of a joint to accommodate contraction on the other side. … The central nervous system sends a message to the agonist muscle to contract.
ascending pathways
via the dorsal column-medial leminscal pathway
what part detects the muscle stretch?
sensory component (middle) , it is very sensitive to change
what part contracts
motor component (ends), when they have too much slack the sensory component cannot detect movement
intrafusal fibers are innervated by
gamma motor neurons
alpha, gamma
extrafusal, intrafusal
alpha = extrafusal
gamma = intrafusal
which sensitivity response is to change in length
static (stationary)
which sensitivity response is to change in velocity
dynamic (movement)
low gamma activation =
you have to really stretch a muscle before the spindles can detect stretch a stretch reflex to bring yourself back to center position
high gamma activation =
too hard for you to stay in a relaxed state, any little movement or change in length of stretch muscles would cause a reflex
where are GTO located
- the junction of the muscle and the tendon
- in series with extrafusal muscle fibers
what innervated GTOs
Group Ib afferents
what do GTO provide information on
muscle tension (force of muscle contraction)
