Organisation & Location of UMN pathways Flashcards
what is the role the reticulospinal tracts? [1]
formed from? [2]
what is the role the reticulospinal tracts? [1]
influence voluntary movement: mainly of axial and girdle muscles for postural stability (makes sure we switch on right muscles to not fall over)
formed from? [2]
RF of pons [1] & medulla [1]
describe how reticulospinal tracts from
a) pons
b) medulla
descend xx
describe how reticulospinal tracts from
a) pons: descend ipsilaterally as medial reticulospinal tract
b) medulla: descend bilaterally in the lateral reticulospinal tract
descend xx
describe the functions of the reticulospinal tracts from
a) medial reticulospinal tract (from the pons)
b) lateral reticulospinal tract (from the medulla)
descend xx
describe the functions of the reticulospinal tracts from
a) medial reticulospinal tract (from the pons)
* *control axial and extensor motor neurons = extension of legs**
* *stepping**
b) lateral reticulospinal tract (from the medulla):
flexor motor neurons
inhibits medial reticulospinal tract: switches off extensors & modulates stretch reflex
BOTH are located in white matter !!
extensor muscles are associated with
medial reticulospinal tracts
lateral reticulospinal tracts
extensor muscles are associated with
medial reticulospinal tracts
lateral reticulospinal tracts
steering of head and trunk in response to external stimuli is associated with:
medial reticulospinal tracts
lateral reticulospinal tracts
steering of head and trunk in response to external stimuli is associated with:
medial reticulospinal tracts
lateral reticulospinal tracts
reduces muscle tone (atonia), especailly when in REM sleep:
medial reticulospinal tracts
lateral reticulospinal tracts
reduces muscle tone (atonia), especailly when in REM sleep:
medial reticulospinal tracts
lateral reticulospinal tracts
what is the role of potine reticular formation? [2]
does the pontine reticular formation descend ipsi or contralaterally? [1] in which part of stem? [1]
what is the role of potine reticular formation? [2]
axial and extensor motor neurons
stepping
does the pontine reticular formation descend ipsi or contralaterally?
ipsilaterally on medial side
what is the role of medulla reticular formation? [2]
does the medulla reticular formation descend ipsi or contralaterally? [1] in which part of stem? [1]
what is the role of medulla reticular formation? [2]
flexor motor neurons
inhibits medial reticulospinal tract
does the medulla reticular formation descend ipsi or contralaterally? [1] in which part of stem? [1]
bilaterally in lateral reticulospinal tracts
which out of medial / pontine reticulospinal or lateral reticulospinal is for posture?
medial / pontine reticulospinal
lateral reticulospinal
which out of medial / pontine reticulospinal or lateral reticulospinal is for posture?
medial / pontine reticulospinal
lateral reticulospinal
which out of medial / pontine reticulospinal or lateral reticulospinal makes your body floppy / loss of muscle tone (atonia) when you sleep?
medial / pontine reticulospinal
lateral reticulospinal
which out of medial / pontine reticulospinal or lateral reticulospinal makes your body floppy / loss of muscle tone (atonia) when you sleep?
medial / pontine reticulospinal
lateral reticulospinal
which of the following facilitates y-motor neurons of extenors of body?
corticospinal tract
anterior spinocerebellar tract
posterior spinocerebellar tract
lateral reticulospinal tract
medial reticulospinal tract
which of the following facilitates y-motor neurons of extenors of body?
corticospinal tract
anterior spinocerebellar tract
posterior spinocerebellar tract
lateral reticulospinal tract
medial reticulospinal tract
which of the following inhibits y-motor neurons of extenors of body?
corticospinal tract
anterior spinocerebellar tract
posterior spinocerebellar tract
lateral reticulospinal tract
medial reticulospinal tract
which of the following inhibits y-motor neurons of extenors of body?
corticospinal tract
anterior spinocerebellar tract
posterior spinocerebellar tract
lateral reticulospinal tract
medial reticulospinal tract
after information comes inm where is the main region of the brain that decides if action should be sympathetic or parasympathetic? [1]
after information comes inm where is the main region of the brain that decides if action should be sympathetic or parasympathetic? [1]
nucleus of solitary tract!
how does the reticulospinal tract influence body’s autonomic control? !!
reticulospinal tract projects to the preganglionic autonomic neurons (both parasympathetic and sympathetic) SO if damaged: get loss of blood pressure, temp regulation and bladder and bowel control
explain v basic overview of afferent –> motor for autonomic control x
- afferent receptors (like baroreceptors / chemoreceptors etc) go via visceral sensory afferents to brain & hypothalamus
- autonomic control system (i_n hypothalamus AND reticular formation_) sends information to motor output (para or sym)
how does RF influence respiratory control? [2]
- pneumotactic centre (superior pons) sends inhib impulse to inspiratory centre of medulla: switches off inspiration (allows you to breathe out !! )
- apneustic centre (inferior pons) prolongs inspiration (increases depth of inspiration for 2 secs then inhibited by pneuomotaxic centre)
how does RF influence pain modulation? [2]
what happens to this system during sleep? [1]
serotonergic raphe magnus nucleus
&
noradrenergic cell groups
activation causes inhibition of nociceptive (pain) information
what happens to this system during sleep? [1]
reduces in sleep
which of the following influences conciousness by modulating generalised arousal level?
noradrenaline
ACh
serotonin
dopamine
adrenaline
which of the following influences conciousness by modulating generalised arousal level?
noradrenaline
ACh
serotonin
dopamine
adrenaline
which of the following influences conciousness by modulating attention (direction of conciousness)?
noradrenaline
ACh
serotonin
dopamine
adrenaline
which of the following influences conciousness by modulating attention (direction of conciousness)?
noradrenaline
ACh
serotonin
dopamine
adrenaline
which of the following influences conciousness by modulating selection of object of attention, based upon goals?
noradrenaline
ACh
serotonin
dopamine
adrenaline
which of the following influences conciousness by modulating selection of object of attention, based upon goals?
noradrenaline
ACh
serotonin
dopamine
adrenaline
which of the following influences conciousness by modulating motivation and motor activity?
noradrenaline
ACh
serotonin
dopamine
adrenaline
which of the following influences conciousness by modulating motivation and motor activity?
noradrenaline
ACh
serotonin
dopamine
adrenaline
how does reticular activating system (RAS) influence sleep?
neurons in the RF can set the pace of acivity in neurons throughout the brain:
e.g:
ascending arousal system
during alert wakefulness (low voltage, fast electrical activtity in EEG)
during deep sleep (high voltage, slow electrical activtity in EEG)
what happens to delta wave of EEG during sleep?
what happens during REM sleep?
delta waves in EEG block transmission of sensory information to thalamus !
REM sleep: in beta rhythms (similar to being awake), but also have atonia (keep you asleep)
** learn ! **
which part of the brain is sleep promoting [1]
which parts are arousal promoting? [2]
sleep promoting:
anterior hypothalamus. inhibit wake promoting neurons
ascending arousal systems:
RF
Posterior hypothalamus
