week 2 quiz Flashcards
what spinal level is involved in the monosynaptic stretch reflex?
spinal level L4
what is the receptor type for the monosynaptic reflex? (phasic stretch)
muscle spindle
what is the effector organ for this reflex?
extrafusal muscle fibers of striated quadriceps muscle
what are the fiber types of the afferent and efferent axons involved in the monosynaptic reflex?
1a afferent fibers from the muscle spindle to efferent alpha motor neurons
define reciprocal inhibition
contraction in a muscle (agonist) is accompanied by a loss of tone or relaxation in the antagonistic muscle
what role does reciprocal inhibition play during normal movement?
for efficient motor control, prevention of unwanted activity in antagonist muscles is necessary. with voluntary movement, it is necessary to prevent antagonistic opposition to the movement
which type of neuron is responsible for the integration of polysynaptic spinal reflexes?
interneuron
describe crossed extension reflex
an extension of the lower extremity on the opposite side when a painful stimulus is applied to the skin
what is alpha motor coactivation?
when intrafusal and extrafusal muscle spindles contract simultaneously
Describe withdrawal reflex
with a noxious stimulus, free nerve endings are stimulated and reflexive withdrawal of a body part occurs.
list anatomical structures of the peripheral nervous system for both the somatic and autonomic nervous systems.
receptors, afferent fibers of the peripheral nerve, dorsal root and ganglia, dorsal rootlets, synapse in anterior horn cells (lower motor neurons) ventral rootlets, ventral root, spinal nerve, peripheral nerve, sympathetic ganglia of the ANS, end organs. somatic: muscle, ANS viscera and vasculature
what is the difference between alpha and gamma motor neurons?
alpha motor neurons control contraction of muscle fibers in voluntary movement while gamma motor neurons control contraction in a stretched position, stretch reflex
