KIN 255 - stimulus evoked behaviours

H-reflex

a common neurophysiological tool to asses the stimulus-response characteristic of the myotatic reflex pathway

fusimotor drive changes relationship from a stimulus to the output

stimulating a nerve directly removes influence of spindle fiber because

afferent sensory nerve

The H reflex is the motor response elicited by the electrical stimulation of the

efferent motor nerve

The m wave is the motor response elicited by the electrical stimulation of the

set stimulus to a point where sensory neuron threshold is met

how can we only see a H-reflex without seeing a M wave

true

Action potentials are not unidirectional t or f

orthodromic direction

when a sensory nerve is stimulated, the Ia afferent goes to the spinal cord then goes to motor neuron for muscle, this is what kind of direction

antidromic direction

A motor nerve is activated from a stimulus and goes to the spinal cord to the Ia afferent nerve, this pathway is what direction

H wave goes away due to motor units not being able to contract

what happens when M wave is too big

golgi tendon organ reflex

the inverse myotatic reflex is also known as what

alpha motor neuron excitation

strong excitation of the IB afferent due to extreme muscle tension overrides what

inhibitory neuron

how does GTO excitation leas to less excitation of the alpha motor neuron

homonymous

is a GTO reflex homonymous or heteronymous

disynaptic

is a GTO reflex monosynaptic or disynaptic

GTO activity --> alpha motor neuron inhibition

the inverse myotatic reflex done at rest with

alpha motor nerve excitation

excitation of Ib afferent facilitates

sum of different pathways

realistically, the inverse myotatic reflex is the

state/phase dependent reflex

the effect of muscle state on the stimulus-response relationship of the inverse myotatic reflex

withdrawal reflex

a polysynaptic spinal reflex that requires ipsilateral and contralateral muscle coordination

nociceptor , III or IV

what primary sensory receptor and nerve type would provide afferent information during withdrawal reflex

flexors/agonists excite on ipsilateral side

a leg that is lifted during the withdrawal reflex would have what be excited and on what side

antagonists excite on contralateral side

a leg that bear weight during withdrawal reflex would have what be excited and on what side

yes = automatic

can a withdrawal reflex be modified

fovea

responsible for high-acuity and part of the retina with the highest density of cones

foveal vision

middle 5 degrees around the point of eye fixation. this point in our environment can be changed by moving the eyes

blind spot

all axons form the optic nerve here causing light to be unable to cross through the mass

visual axis

the straight line path from the light that is directed to the fovea

optical axis

the straight line passing through the geometrical centre of the lens

direction of gaze

the direction of the visual axis relative to the environment

gaze angle

the angular measurement of the direction of gaze in the horizontal or vertical plane

extraocular muscles

muscles in the eye that control the horizontal, vertical, and rotational movement of the eyes

abducens nerve

lateral rectus extraocular muscle is innervated by what nerve

oculomotor nerve

the medial, superior and inferior rectus and inferior oblique of the extraocular muscles is innervated by what nerve

trochlear nerve

the superior oblique extraocular muscle is innervated by what muscle

conjugate / version

coordinated eye movement in the same direction through the same angle

disconjugate / vergence

coordinated eye movement in which the eye moves in opposite directions through mirrored angles

smooth pursuit

conjugate eye movements helps with what behavior

depth perception

disconjugate eye movements helps with what behavior

vestibulo-ocular reflex

helps stabilizes gaze in response to head rotation

optokinetic reflex

combo of slow and fast eye movements to keeps a moving scene stationary on the retina

saccades

rapid ballistic eye movements that change the point of fixation or changing fovea focus

smooth pursuit

eye movements to keep the eyes fixated on a moving object

vergence

coordinated movement of both eyes to obtain or maintain a binocular vision

nuclei in the brain stem

rapid compensatory eye movements that help stabilize the direction of the gaze is controlled by what

input

the head rotation (from vestibular nerve) is considered the

output

the extraocular muscle activity (abducens, oculomotor and trochlear nerves) is considered the

opposite

eyes will rotate in the ______ direction to the head

counterrotate

what cancels out the rotation of the head, since the eyes move with the head

lateral rectus, medial rectus

in horizontal head rotation, a projection from the abducens to oculomotor nucleus coordinates activity if the ______ from one eye with the ________ of the other eye

agonists --> L medial rectus and R lateral rectus

if the head is rotating left but keeping the eyes straight, what muscles are being excited for contraction ?

vestibular nuclei

if the head is rotating left but keeping the eyes straight, antagonists need to relax, meaning the inhibitory neuron is needed, which is in the

antagonist --> L lateral rectus and R medial rectus

if the head is rotating left but keeping the eyes straight, what muscles are being inhibited

exogenously and endogenously driven

what are the two types of saccades

retina --> oculomotor nuclei

for saccadic eye movement what would the input and output be

false

exogenous driven saccades uses the cortex t or f

brain stem

exogenous driven saccades uses what instead

true

endogenous driven saccades uses the cortex t or f

express saccades

this stimulus-response pathway bypasses the cortex and is quick to start

prosaccades (reflex) saccades

the stimulus response pathway traverses cortex, and takes longer to route through the visual cortex

predictive saccades

eye movement to a point in space where a stimulus is expected but not yet occuring

memory guided saccades

eye movement to a point in space where a stimulus is located but not anymore

anti-saccade

eye movement in the opposite direction to a stimulus and require inhibition of reflexive saccade

saccade sequence

a learned order of eye movements to fixate a series of points in space

endogenously driven saccades

self-directed and initiation of saccade is driven by internal choice

parietal and frontal

commonly, endogenously driven saccades will involve what cortices