Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuroanatomy SP15 > Reticular Formation and Cerebellum > Flashcards

Reticular Formation and Cerebellum Flashcards

1
Q

where does the brainstem travel through and extend?

A

into the cerebrum as the hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what does the reticular formation regulate?

A

posture, stereotypic motor behaviors, internal environment, pain regulation, sleep and wakefulness and emotional tone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the 3 zones of the Reticular formation?

A

Raphe (median), medial and lateral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Raphe Nuclei

A

immediately adjacent to the sagittal plane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Medial zone

A

alongside raphe, mixture of large and small neurons
-source of most ascending and descending projections cell bodies originate here
(ascend to the cerebrum or descend to spinal cord for example)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Lateral zone

A
  • prominent in rostal medulla and caudal pons, but most extensive zone of the reticular formation
  • cranial nerve reflexes and visceral functions (nucleus ambiguous here that is a relay for vagus nerve)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Sleep paralysis

A
  • The RF has extensive and complex connections that can innervate multiple levels of the spinal cord, brainstem and thalamus
  • the RF has a descending reticulospinal tract that keeps muscles flaccid while sleeping and another that contributes to dreams (so that you dont run away from mud monster!)
  • If you have a problem with this part of your RF in the pons, you cannot move but when the cerebrum “wakes up”
  • “living through a dream”, tightness on chest, hallucinations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the 2 reticulospinal tracts for reticular MOVEMENT/CONTROL

A
  • Medial (pontine) reticulospinal tract starts in the pons, remains ipsalateral and descends near the MLF in the anterior funiculus ((major one during sleep))
  • Medullary (lateral) reticulospinal tract starts in the medulla and descends bilaterally in the lateral funiculus
  • *both synapse in the anterior horn of the spinal cord
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what major tract is the reticulospinal tract an alternative for?

A

corticospinal tract, in regulating spinal motor neurons (directly)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how does the RF regulate spinal reflexes?

A

so that only noxious stimuli evoke a reflex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

where do reticulospinal tract neurons receive input from??

A

cerebral cortex, basal ganglia, substantia nigra

**receives input from many areas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain RF and walking movement

A
  • RF contains basic neural machinery for complex patterned movement
  • brainstem-diencephalon junction in cat cut out and the cat still walks (remnant of the rhythm in humans is walking and swinging arms)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Motor patterns in the reticular formation

A
  • gaze centers (midbrain for vertical and pons for horizontal)
  • mastication in the supratrigeminal nucleus (pons)
  • locomotion in the pons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is controlled in the Medulla “vital center”

A

heart rate, respiration, swallowing and vomiting

**cluster in the RF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Bruxism causes

A

During sleep all mm. are supposed to be in atonia, but in bruxism, the jaw mm. are co-contracted (openers and closers both working)

  • peripheral causes theory blames malocclusion and the jaw constantly trying to reach resting postions
  • the central causes theory says that sleep related dysfunctions to the supratigeminal nucleus is the issue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Explain how pain is transmitted in the RF

A

spinomesenchephalic/STT receives pain (post. horn sc) and goes to the PAG, which gets input from the hypothalamus, cortex, etc that controls whether or not pain should be suppressed (ex. wounded soldier) , the PAG then goes to the nucleus raphe magnus then to the posterior horn of the spinal cord
**the spinomesencephalic tract can also go directly to the RF or the thalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

opiates and pain

A
  • opiates can activate the PAG-raphe at many levels (PAG, raphe or posterior horn)
  • can inhibit spinothalamic tract directly , indirectly through interneurons or can inhibit pain afferents from even going through the STT
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is comparable to pattern generators in motor control

A

visceral information that reaches the RF

  • responds to environmental changes and projects to brainstem autonomic nuclei
  • *inspiration, expiration, rhythm of breathing in pons and medulla, heart rate ad and blood pressure in medulla
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Explain the ARAS (ascending reticular activating system)

A

-the reticular formation projects to the thalamus which in turn projects to the cortex that work together to control consciousness
-functional, not anatomic
(PET scan from an attention demanding task)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

is there is bilateral damage to the midbrain RF what happens?

A 
prolonged coma
(midbrain and pons RF are whats important for heightening arousal to sensory stimuli that demand attention)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

where are Noepinephrine neurons located?

A

solitary nucleus in medulla, locus ceruleus in the rostral pons (near the 4th ventricle) and ventrolateral medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what does the locus ceruleus control?

A

vigilance and attention

  • active in attentive situations, moderate while awake and low activity when asleep
  • releases noepinephrine to the cortex that directs attention to the stimulus
  • releases noepinephrine to the trigeminal spinal nucleus and spinal cord to suppress incoming pain signals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

where do noepinephrine neurons project?

A

practically the entire cortex, heavily in to the primary somatosensory cortex, goes through the medial forebrain bundle

24
Q

low levels of norepinephrine lead to

A
  • clinical depression
  • reduced locus ceruleus neuron activity
  • *parkinsons disease has loss of locus ceruleus neurons
25
Q

high levels of norepinephrine lead to

A

panic disorder

26
Q

where are dopamine neurons located?

A

in the substantia nigra and ventral tegmental area in the midbrain

27
Q

where does dopamine travel?

A

from the substantia nigra to the putamen and caudate and from the ventral tegmental area to the cortex or limbic system

28
Q

what does the nigrostriatal path control?

A

motor activity (degenerates in parkinsons)

29
Q

what do mesocortical and mesolimbic fibers control?

A
  • mesocortical fibers have heavy projections to the frontal cortex to stimulate organized thinking and planning
  • mesolimbic fibers project to nucleus accumbens and amygdala and control emotional reward (what causes drug dependency)
30
Q

Schizophrenia

A

has two parts: hallucinations and social withdraw
the hallucinations are due to high levels of dopamine in the limbic system and social withdrawl is due to low levels of dopamine in the prefrontal cortex
**imbalance of dopamine levels

31
Q

where are serotonin neurons located?

A

in all of the brainstem levels in the raphe

**Nucleus raphe magnus modulates pain control

32
Q

projections of the serotonergic neurons

A

midbrain raphe to the cortex

  • *much like Norepinephrine (but heavy in somatosensory AND limbic system)
  • inhibits distracting stimuli and regulates day-to-night cycle in the hypothalamus
  • medullary raphe project to the spinal cord to suppress pain
33
Q

Controlling serotonin levels

A

low levels of serotonin are due to high carbohydrate diets and high levels are due to compulsive behaviors and anorexia

34
Q

Where are cholinergic neurons located?

A
  • basal nucleus of Meynert (main source) and in part of the RF called the dorsolateral pontine tegmentum (near the locus cerelus)
  • *Remember Ach is also the neurotransmitter used by motor neurons, preganglionic autonomic neurons and postganglionic parasympathetic neurons (CNIII and X)
35
Q

Alzheimers disease

A

-drug treatment inhibits Ach to slow the breakdown of Ach (in the basal nucelus)

36
Q

What part of the substantia nigra are the dopaminergic neurons coming from?

A

the compact part (black dots)

37
Q

What do SSRI’s do?

A

alleviate clinical depression

selective serotonin reuptake inhibitors

38
Q

What does the dorsolateral pontine tegmentum control?

A

sleep and wakefulness

39
Q

where is the gray and white matter located respectively in the cerebellum?

A

on the outside and inside respectively

40
Q

what are the functions of the cerebellum?

A

regulates equilibrium, controls muscle tone, motor coordination prior to the event and adjustment during the movement

41
Q

inferior cerebellar peduncle function

A

IN pathway from the spinal cord and brainstem

**restiform and sometimes juxtarestiform body

42
Q

middle cerebellar peduncle function

A

IN pathway from motor signals from the cortex
(brachium pontis)
**largest peduncle

43
Q

superior cerebellar peduncle function

A

OUT pathway to the red nucleus and thalamus

44
Q

describe the cerebellar circuitry

A

inputs come into the ICP and MCP, the ICP and MCP project out to the cortex, which does its thing, the cortex then sends info to the deep nuclei which in turn send to the SCP which projects to other parts (other than the cerebellum) of the brain

45
Q

what are all the deep nuclei?

A

dentate, interpose (emboliform and globose) and fastigal

“Frosch Gives Everyone D’s”

46
Q

what is the only cell to leave the cerebellar cortex?

A

purkinje cell

47
Q

where do the climbing fibers originate and what do they climb?

A

the inferior olivary nucleus and they climb dendrites of purkinje cells

48
Q

what are the collateral to deep nuclei and what do they do?

A

they come from the climbing fibers and mossy fibers to keep their function in check

49
Q

what are the deep nuclei neuronal populations?

A

-they are a source of mossy fibers into the cortex and a source of neurons whose axons leave the cerebellum

50
Q

vestibulocerebellum

A
  • contains flocculonodular lobe and part of the vermis
  • gets inputs from the vestibular end organ and vestibular nuclei to control eye movement in relation to head movements (balance)
  • goes to to the fastigal nucleus
51
Q

spinocerebellum pathway

A

the spinocerebellar tract goes to the paravermal area then to the interposed nuclei which take the SCP to the red nucleus or VA/VL of the thalamus to the corticospinal tract (which regulates trunk and limb movements)

52
Q

pontocerebellum pathway

A

information from the primary motor, supplementary motor, premotor and parietal lobe info goes to the baislar pons, which crosses over (to form the MCP) to travel on mossy and climbing fibers to the lateral cerebellar cortex, which goes to the dentate nucleus, up the SCP to the thalamus and then ultimately back to the motor cortex etc..
***LOOP that controls speech and coordination of arm movement

53
Q

what does cerebellar cortex injury lead to??

A

failure to coordinate multiple mm. moves

ex. intention tremor and dysmetria

54
Q

lateral vs. medial cerebellar limb movements??

A

lateral is planned, learned movements whereas the medial hemisphere is adjusting limb movements
ex. a good baseball player will only use their lateral hemisphere whereas a poor baseball player will use there medial and lateral hemisphere to adjust movements that are off

55
Q

what does injury to the vermis cause?

A

disturbances in balance (even when seated), gait ataxia

ex. drunk people

56
Q

explain why the cerebral hemisphere controls contralateral muscles but the cerebellum influences ipsalateral limbs

A

the spinocerebellar pathways are all ipsalateral wheres projections from the cerebellum to the thalamus and then cortex are contralateral

Neuroanatomy SP15 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions