Test 3.2 Flashcards
define reflexes
sensory motor circuits
what happens if you increase or decrease the gain of stimulus
it will cause an increase or decrease in the gain of response
true or false
all sensory and motor neurons are excitatory
true
when is perturbation applied
during the time course of a catching task
how can response to perturbation be reversed
depending on control state
whats the characteristic of M1
20-40ms
monosynaptic
low threshold and gain
whats the characteristics of M2
40-60ms
latency Multisynaptic
High threshold and gain
is M1 or M2 seen is the contralateral hand
M2
what is muscle tone referred to as
stiffness
what does cutting the dorsal root result in
a non-linear response to stretch, the muscle ‘give way” rapidly to stretch
what does the stretch reflex add to
adds to stiffness to muscles and makes muscles respond smoothly to stretch
what is the stretch reflex set up to do
resist movement
whats the characterisitcs of normal muscle tone
flexible, but sturdy truck and limbs
whats the characteristics of abnormal muscle tone
floppy trunk and stiff limbs
what does more complex circuits result in
more detail patterns of motor coordination
what does the flexor withdrawl reflex compose
- pain response
- you extend the opposite leg and flex the leg injury
- slow response
- causes inhibition of extensors
define dorsal rhrizotomy
no dorsal root input to spinal cord
what does serotonin regulate
sleep wake cycle
what is the most common reflex
stretch reflex
what are reflexes made of
1 or more sensory neuron, 1 or more interneuron, 1 or more motor neuron
what happens if a interneuron has a lot of alpha neuron
you get a big response
what does the antagonist muscle do during the stretch reflex
inhibits the muscle
true or false
each muscle spindle monosynaptic activates one motor unit in that muscle
false
it activates ALL the motor units in that muscle
what happens if you have a bifurcation of descending neurons
you end up getting M1 only on one side and M2 on both side
which neuron helps resist stiffness of muscles
gamma motor neurons
true or false
stretch reflex helps resist movement
true
true or false
we can control the amplitude of the stretch reflex as well as babies
humans can control the stretch reflex but babies can not
what type of response is a tonic stretch reflex
sustain response (reflect posture)
true or false
phasic stretch reflex is a very slow response
false it is very quick
true or false
the stretch reflex is a automatic response
true
do babies have good muscle tone
no
true or false
you cannot modulate the stretch reflex
false, you can modulate it
true or false
the stretch reflex causes inhibition of the antagonist muscle
true
what is modulation of reflexes important for
regulating posture and movement
is stretch reflex responsible for linear or rotational motion
linear
what are the two major spinal circuits
spinal reflexes and central pattern generators
explain what the flexor withdrawl reflexes is made up of
multisynaptic
thin neurons
slow response
pain reflex
what are central pattern generators
they are self contain circuits in the spinal cord that give rhythmic locomotion info
true or false
central pattern generators also exist in mammals, humans, and new born babies
true
