Reticular Formation & Cerebellum

Question 1

The ___ ___ is phylogenetically a very old neural network.

Answer 1

reticular formation

Question 2

The reticular formation is a polysynaptic network in the ____ that continues rostrally into the ___ and ____.

Answer 2

brainstem; thalamus; hypothalamus

Question 3

What is the function of the reticular formation?

Answer 3

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

Question 4

what are the three longitudinal zones (medial to lateral) of the reticular formation?

Answer 4

raphe (median) nuclei; medial (paramedian) zone; and lateral zone

Question 5

The raphe nuclei is immediately adjacent to which plane?

Answer 5

sagittal

Question 6

Which zone contains a mixture of large and small neurons and is a source of most ascending and descending projections?

Answer 6

medial zone

Question 7

where is the the lateral zone prominently located?

Answer 7

rostral (upper) medulla and caudal (lower) pons

Question 8

which zone is primarily involved in cranial nerve reflexes and visceral functions?

Answer 8

lateral zone

Question 9

what two reticulospinal tracts are involved in movement control?

Answer 9

medial and lateral

Question 10

What area of the brainstem does the medial RST begin?

Answer 10

pons

Question 11

T/F. The medial RST remains ipsilateral as it descends.

Answer 11

True.

Question 12

The medial RST descends near the ____ and in the ___ ____.

Answer 12

MLF; anterior funiculus

Question 13

What area of the brainstem does the lateral RST begin?

Answer 13

medulla

Question 14

The lateral RST descends ____ in the ____ funiculus.

Answer 14

bilaterally; lateral

Question 15

why is the reticular formation a major alternative to corticospinal tract in regulating spinal motor neurons?

Answer 15

It influences spinal motor neurons directly and regulates spinal reflexes - so that only noxious stimuli evoke a reflex.

Question 16

what are six examples of rhythmic motor patterns found in the brainstem reticular formation?

Answer 16

1. gaze centers
2. mastication
3. locomotion (pons)
4. heart rate
5. respiration
6. swallowing/vomitting

Question 17

what three rhythmic motor patterns are controlled by the medulla’s “vital center”?

Answer 17

heart rate
respiration
swallowing/vomitting

Question 18

A 25 y/o male presents complaining of jaw muscle discomfort upon waking. You notice abnormal wear of the teeth. What is the diagnosis?

Answer 18

Bruxism

sounds, abnormal wear of teeth, jaw muscle discomfort upon waking, and seen in younger individuals

Question 19

With sleep bruxism, all muscles are in a state of ___.

Answer 19

atonia

Question 20

T/F. In bruxism, the jaw muscles are co-contracted.

Answer 20

True. Both jaw opening and jaw closing muscles are contracted at the same time

Question 21

what are the two theories on bruxism?

Answer 21

peripheral causes and central causes theories

Question 22

Which theory states that malocclusion results in premature and one-sided contact?

Answer 22

peripheral causes theory

Question 23

In peripheral causes theory, jaw movements continue in an attempt to reach the ___ position.

Answer 23

resting

Question 24

What is the peripheral causes theory based on?

Answer 24

clinical observations and experience with treatment

Question 25

With central causes theory of bruxism, what is the cause?

Answer 25

sleep related dysfunctions

Question 26

Input to the _____ nucleus may be from ___ ___, lateral ____, and central nucleus of the ____.

Answer 26

supratrigeminal; basal ganglia; hypothalamus; amygdala

Question 27

What pathway is key to the fact that the nervous system can suppress or facilitate pain, depending on the circumstances?

Answer 27

reticular formation

Question 28

T/F. The periaqueductal gray is central to one well described pain excitation system.

Answer 28

False, The PAG is central to pain SUPPRESS system

Question 29

PAG receives pain info from _____ fibers.

Answer 29

spinomescencephalic

Question 30

PAG may also contain ___ state info - for example, should pain suppression be activated?

Answer 30

behavioral

Question 31

Describe the pathway of RF and pain?

Answer 31

PAG to (magnus) raphe nucleus (in medulla) then to posterior horn or spinal cord/spinal V nuclues

Question 32

Many fibers of RF liberate ___, which excites inhibitory interneurons in the posterior gray horn and spinal trigeminal nucleus.

Answer 32

serotonin

Question 33

Raphe can inhibit ___ directly or indirectly by activating interneurons that inhibit ___. It can also directly inhibit pain ___(afferents/efferent).

Answer 33

STT(spinothalamic tract); STT; afferents

Question 34

___ receptors are abundant in PAG, raphe and posterior horn of the cord

Answer 34

Opiate

Question 35

A lot of ___ information reaches the RF, which responds to environmental changes and projects to brainstem ____ nuclei and spinal cord.

Answer 35

visceral; autonomic

Question 36

T/F. Centers controlling inspiration, expiration rhythm of breathing are located in the midbrain.

Answer 36

False. Pons and Medulla

Question 37

T/F. Heart rate and blood pressure are controlled in the medulla.

Answer 37

true.

Question 38

RF projects to the ___ and ___ for arousal and consciousness.

Answer 38

thalamus and cortex

Question 39

___ and ___ RF get input from multiple sensory modalities (e.g. pain) and project to ____ ____ nuclei, which project diffusely to the cortex.

Answer 39

Midbrain and pons; thalamic intralaminar

Question 40

Which RF projections work together to modulate cortical activity?

Answer 40

thalamic intralaminar nuclear projections to cortex and monoamine reticular projections

Question 41

___ (Unilateral/Bilateral) damage to the midbrain RF results in prolonged coma. This is known as the ___ ___ ___ ___ (ARAS). This system also has a role in sleep-wakefulness cycle.

Answer 41

Bilateral; ascending reticular activating system

Question 42

What neurochemicals affect the brainstem? Hypothalamus? Telencephalon?

Answer 42

NE, dopamine, serotonin Histamine containing neurons Acetylcholine

Question 43

NE neurons are found in the ___ ___ of the medulla and ___ ___ and VL medulla of the ___ pons.

Answer 43

solitary nucleus; locus ceruleus; rostral

Question 44

NE neurons are found in the ___ ___ of the medulla and control memory enhancement. They are also found in the ___ ___ and VL medulla of the ___ pons.

Answer 44

solitary nucleus; locus ceruleus; rostral

Question 45

T/F. The locus ceruleus controls pain regulation and the ventralateral medulla is involved in cortex (arousal) vigilance and attention, which is more active in attentive situations.

Answer 45

False, locus ceruleus = cortex (arousal) vigilance and attention, which is more active in attentive situations. Ventralateral medulla is involved in pain regulation via the spinal cord.

Question 46

NE projections in the locus ceruleus innervate practically the entire CNS with heavy projections going to the ___ cortex.

Answer 46

somatosensory

Question 47

Stimulation of the ___ ___ produces increased state of arousal. NE released in the ___ facilitates attention to that stimuli. NE released in the ___ ___ nucleus and spinal cord suppresses incoming ___ signals.

Answer 47

locus ceruleus; cortex; trigeminal spinal; pain

Question 48

Patients suffering from clinical depression have decreased levels of what neurotransmitter?

Answer 48

NE

Question 49

Depression and decreased ___ leads to reduced locus ceruleus activity. Patients suffering from ___ disease have lost neurons in the locus ceruleus and suffer from depression.

Answer 49

NE; Parkinson's

Question 50

Pain disorder is associated with what neurotransmitter?

Answer 50

increased levels of NE

Question 51

Where can you find dopaminergic neurons in the midbrain?

Answer 51

substantia nigra (putman and caudate) and the ventral tegmental area (limbic system)

Question 52

What are the two tracts of the ventral tegmental area?

Answer 52

mesolimbic and mesocortical

Question 53

The ___ tract project fibers to the limbic system, specifically the nucleus ___ where there is a sense of reward and ___ dependency.

Answer 53

mesolimbic; accumbens; drug

Question 54

The ___ tract sends fibers to the ___ cortex that organizes and initiates behavior.

Answer 54

mesocortical; frontal

Question 55

What area is implicated in the development of disorganized thinking (frontal lobe) and hallucinations (limbic system) in patients suffering from schizophrenia?

Answer 55

ventral tegmental area

Question 56

Social withdrawal in schizophrenic patients is due to ___ levels of dopamine in the ___ cortex. Hallucinations are caused by ___ levels of dopamine in the ___ system.

Answer 56

low; prefrontal; high; limbic

Question 57

T/F. Drugs that lower the level of dopamine are effective in reducing hallucinations.

Answer 57

True.

Question 58

Serotonergic neurons are located in all brainstem levels in the ___ nuclei. Projections are very extensive to ___ and ___ areas.

Answer 58

Raphe; sensory; limbic

Question 59

How do serotonergic neurons of the raphe nuclei play a role in attention?

Answer 59

by inhibiting distracting stimuli

Question 60

Which raphe nuclei plays a role in pain suppression?

Answer 60

nucleus raphe magnus

Question 61

What type of serotonin drugs are given to depressed patients?

Answer 61

selective serotonin reuptake inhibitors (SSRI)

Question 62

What do low levels of serotonin lead to?

Answer 62

1. high carbohydrate consumption (obese women) | 2. binge eating

Question 63

What do high levels of serotonin lead to?

Answer 63

compulsive behavior and anorexia nervosa

Question 64

Drugs that increase the level of serotonin are used to treat...

Answer 64

Depression | Anxiety

Question 65

___ is a neurotransmitter of ___ neurons found in the basal forebrain and basal nucleus(of Meynert). It is also part of the RF in the ___ ___ ___.

Answer 65

Acetylcholine (ACh); dorsolateral pontine tegmentum

Question 66

Damage to cholinergic neurons in the basal forebrain or basal nucleus lead to what disease?

Answer 66

Alzheimer disease

Question 67

How do cholinesterase inhibitors work?

Answer 67

slow breakdown of ACh