Postural Control and Locomotion

Question 1

wheere are the motor neurons innervating axial and prozimal muscles located

Answer 1

meidal area of anterior horn

Question 2

where are the motor neurons innervating distal muscles located

Answer 2

lateral area of anterior horn

Question 3

what are ventromedial pathways invovled in

Answer 3

posture and locomotion of axial and proximal muscles

Question 4

what is origin of lateral vestibulospinal tracts

Answer 4

vestibular nuclei

Question 5

where do lateral vestibulospinal tract descend

Answer 5

all levels of spinal cord

Question 6

what is the function of lateral vestibulospianl tracts

Answer 6

facilitate motor neurons of extensor muscles

affect posture

Question 7

origin of medial bestibulospinal tract

Answer 7

bestibular nuclei

Question 8

where do medial vestibulospinal tract descend

Answer 8

upper thoracic cord

Question 9

function of medial vestibulospinal tract

Answer 9

mediation of reflex head movements in response to vestibular stimuli
adjust position of head

Question 10

origin of pontine reitculospinal tract

Answer 10

pontine reticular formation

Question 11

where does pontine reticulospinal tract descend

Answer 11

all levels of spinal cord

Question 12

function of pontine reitculospinal tract

Answer 12

adjustment of posture and body balance

Question 13

origin of medullar (lateral) reticulospinal tract

Answer 13

medullary reitcualar function

Question 14

function of reticulopsinal system

Answer 14

modulate reflex action during movement

integrate vestibular and other sensory input with motor commands from cerebral cortex

Question 15

origin of tectospinal tract (colliculospinal tract)

Answer 15

superior colliculus

Question 16

where does tectospinal tract project

Answer 16

cervical spinal cord

Question 17

function of tectospinal tract

Answer 17

coordinate head and eye movement

Question 18

posture

Answer 18

overall position of body and limbs relative to each other and in space

Question 19

postural stability

Answer 19

ability to control center of mass in relationship to base of support

Question 20

what system senses body sway

Answer 20

vestibular

Question 21

vection

Answer 21

perception of self-motion induced by visual stimuli

Question 22

what is the position of head controleld by

Answer 22

neck muscles and neck proprioceptions

Question 23

labyrinth righting reflex

Answer 23

head righting reflex that is driven by vestibular input

Question 24

optical righting reflex

Answer 24

visual input that keeps head upright

Question 25

where are asymmetrical tonic neck reflexes seen

Answer 25

birth - 6 mons

Question 26

where is symmetrical tonic neck reflex seen

Answer 26

4/6mon - 12 mon

Question 27

asymmetrical tonic neck reflex

Answer 27

if head is turned to one side, limbs on that side extend and limbs on other side flex

Question 28

symmetrical tonic neck reflex

Answer 28

when next is extended the upper limbs extend and lower limbs flex

Question 29

when do you see tonic neck reflexes

Answer 29

pt with vestibular damage

Question 30

decrebrate posturing

Answer 30

everyting is extended

Question 31

when do you see decrebrate posturing

Answer 31

lesions of upper pons

Question 32

decoritcate posture

Answer 32

arms are flexed and legs are extended when pt is supine

Question 33

whend o you see decorticate posture

Answer 33

lesion of IC, upper midbrain/diencephalon

Question 34

where do humans have stepping pattern generators

Answer 34

inspinal cord

Question 35

SPGs

Answer 35

networks of spinal interneurons that can elicit alteranting patterns of flexion and extension at hip and knee

Question 36

how are SPGs activated

Answer 36

descending input

Question 37

how are actions of both legs coordinated

Answer 37

commissural fibers

Question 38

what is happening with cerebral palsy

Answer 38

too strong of a stretch reflex

Question 39

what happens if you cut the dorsal root

Answer 39

decreased spasticity

Question 40

do Ia fibers affect gamma motor enurons

Answer 40

no, only affect alpha

Question 41

during voltunary action what are you normally stimulating

Answer 41

obth alpha dn gamma moter nruons

Question 42

is stimulation of just gamma motor neurons enough to creat muscle tension

Answer 42

no

Question 43

if gamma motor neurons are excited enough what will happen

Answer 43

they will cause contraction o fintrafusal fibers which stimulates the Ia afferent from the muscle spindle

Question 44

What happens if Ia fibers fire enough

Answer 44

they will excite homonymous muscle's alpha neurons and cause muscle to contract