Reticular Formation and Cerebellum (3)

Question 1

the reticular formation is the central core of the brainstem and extends into the cerebrum as the _____

Answer 1

hypothalamus

Question 2

From medial to lateral what are the 3 longitudinal zones of the RF ?

Answer 2

R and L Median zone - Raphe
Medial Zone - Paramedian
lateral zone (largestt) Zone

Question 3

what zone of the RF houses most of the ascending and descending neural tract projections

Answer 3

Medial or paramedian zone

Question 4

what part of the brainstem would you find the lateral zone of the RF

Answer 4

rostral medulla and caudal pons

Question 5

what zone of the RF is involved with cranial nerve reflexes and visceral functions

Answer 5

Lateral zone

Question 6

what are the 2 reticulospinal tracts of the RF, and where could they be found in the brainstem

Answer 6

• medial reticulospinal tract - pons

- lateral reticulospinal tract - medulla

Question 7

The RF and its reticulospinal tracts are involved with what functions

Answer 7

• regulate spinal motor neurons
• influence spinal motor neurons directly
• regulate spinal reflexes

Question 8

the reticulospinal tract neurons of the RF recieve input from where ?

Answer 8

cerebral cortex
basal ganglia
substantia nigra … (multiple locations)

Question 9

the RF is known to be a “pattern generator”, what does this mean

Answer 9

Controls/coordinates rhythmic motor patterns

• gaze centers (midbrain and pons)
• mastication (pons)
• locomotion (pons)
• medulla vital center

Question 10

the RF is involved with controlling rhythmic motor patterns, and one area of control is the Medulla “vital center” which controls what ?

Answer 10

• respiration
• heart rate
• swallowing/vomiting

Question 11

what is bruxism and what are the theories for what causes this ?

Answer 11

tooth grinding cuz jaw muscles are co-contracted at night

• Peripheral theory - jaw muscles constantly trying to reach occlusion
• Central theory - sleep related neural dysfunction

Question 12

what role can the RF play in pain pathways

Answer 12

Suppress or facilitate pain (wounded soldiers keep fighting)

Question 13

where is the central location that is involved with RF pain supress system

Answer 13

periaqueductal grey (PAG)

Question 14

what zone of the RF would fibers carrying pain infortmation be found ?

Answer 14

Raphe (nucleus magnus) —–> then to posterior horn of spinal cord

Question 15

where would you find opiate receptors in the RF

Answer 15

• PAG
• raphe
• posterior horn of spinal cord

Question 16

What is the RF role in autonomic reflex circuitry

Answer 16

controls visceral information and responds accordingly to environmental changes
(similar to pattern generators in motor control)

Question 17

what part of the brainstem is involved with the RF involvment in arousal

Answer 17

midbrain and pons

-sends info to thalamus then cortex and heightens arousal

Question 18

the RF control of maintaining consciousness is better known as what system

Answer 18

Ascending reticular activating system (ARAS)

Question 19

damage to what part of the brainstem could result in prolonged coma

Answer 19

bilateral damage to midbrain would damage ARAS of RF

Question 20

T/F ARAS has a role in the sleep-wake cycles

Answer 20

True

Question 21

what nuerochemicals involved with the RF are produced in the brainstem

Answer 21

norepinephrine (NE)
dopamine (DA)
serotonin

Question 22

what neurochemicals involved with the RF are produced in the hypothalamus

Answer 22

histamine containing neurons

Question 23

what neurochemical partly involved with the RF is produced in the telencephalon

Answer 23

acetylcholine

Question 24

norepinephrine is made by _______ neurons which are located where ?

Answer 24

noradrenergic neurons

• Rostral pons (locus ceruleus) ***
• medulla (solitary nucleus)

Question 25

sensory info that stimulates the locus ceruleus neurons cause what ?

Answer 25

production of NE (increase arousal and anticipation) | -releases into cortex, trigeminal spinal nucleus, spinal cord

Question 26

reduced locus ceruleus activity (reduced levels of NE) causes what

Answer 26

clinical depression

Question 27

increased activity of the locus ceruleus (increase NE) could cause

Answer 27

panic disorder

Question 28

dopamine is produced by ________ neurons located where

Answer 28

dopaminergic neurons in the midbrain - substantia nigra - ventral tegmental area

Question 29

what tract degenerates in people with parkinsons disease

Answer 29

``` nigrostriatal tract (substantia nigra to striatum) -involved with motor activity from DA ```

Question 30

what are the components of the striatum and what neurochemical has projections through here

Answer 30

caudate and putamen | -dopaminergic projections

Question 31

what is the major source of DA

Answer 31

Ventral tegmental area

Question 32

what are the 2 tracts of the Ventral Tegmental Area

Answer 32

Mesolimbic tract - to limbic system | Mesocortical tract - to frontal cortex

Question 33

what is implicated in schizophrenia ?

Answer 33

the 2 tracts of the ventral tegmental area

Question 34

what are two components of schizophrenia and what is the cause of each

Answer 34

Social withdrawal - low DA levels in prefrontal cortex | Hallucinations - high DA levels in limbic system

Question 35

serotonin is produced by serotonergic neurons which are located where ?

Answer 35

all brainstem levels in raphe of RF

Question 36

serotonergic neurons in the midbrain raphe nuclei project to the ______ and are involved with what ?

Answer 36

Cortex - Focusing/paying attention - hypothalamus day/night cycle

Question 37

sertonergic neurons in the medullary raphe nuclei project to the _______ and are involved with ?

Answer 37

spinal cord | -pain supression (nucleus raphe magnus)

Question 38

Selective Serotonin Reuptake Inhibitors (SSRI) are used to treat ?

Answer 38

Clinical depression

Question 39

Low levels of serotonin would result in ?

Answer 39

Binge eating | high carb consumption (women)

Question 40

high levels of serotonin would result in

Answer 40

complulsive behavior | annorexia nervosa

Question 41

drugs that increase levels of serotonin are used to treat

Answer 41

anxiety and depression

Question 42

Achetylcholine is produced by _____ neurons and are produced where at in the RF

Answer 42

cholinergic | -dorsolateral pontine tegmentum

Question 43

Acetylcholine is largely produced outside of the RF (meaning its just a lil part of RF). Where are these produced

Answer 43

basal nucleus (of Meynert) of basal forebrain

Question 44

what are the main functions of the cerebellum

Answer 44

- regulate equilibrium - regulate muscle tone/posture - motor coordination for voluntary movements in the future (plans) and during execution

Question 45

the surface of the cortex of the cerebellum is composed of _____ matter whereas the _____ matter is inside

Answer 45

grey, white

Question 46

what are the 2 main fissures of the cerebellum and what lobes do they seperate

Answer 46

primary fissure - anterior from posterior lobe | posterolateral fissure - floculonodular lobe from posterior lobe

Question 47

what is the midline of the cerebellum called

Answer 47

vermis

Question 48

what are the 3 lobes of the cerebellum

Answer 48

anterior posterior floculonodular

Question 49

what are the 3 cerebellar peducncles

Answer 49

inferior cerebellar peduncle (Restiform body) middle cerebellar peduncle (brachial pontis) - largest superior cerebellar peduncle

Question 50

where does the inferior cerebellar peduncle recieve input from, and what is its function

Answer 50

spinal cord and brain stem | -monitor muscle and limb movement

Question 51

what is the function of the middle cerebellar peduncle

Answer 51

"IN Pathway" | -recieves afferents from basis pontis and relays motor signals from cortex

Question 52

what is the function of the superior cerebellar peduncle

Answer 52

"out pathway" | -sends efferents to red nucleus and thalamus

Question 53

what are the 4 cerebellar deep nuclei

Answer 53

dentate nuclei interposed nucleus - emboliform and globose fastigal nuclei

Question 54

what is the broad overview of the cerebellar circuitry

Answer 54

- inputs to ICP and MCP (most) - send to cortex - cortex send to deep nuclei - deep nuclei send outputs via SCP

Question 55

what are the 3 structural layers of the cerebellar cortex

Answer 55

- Molecular layer (top) - Perkinjie cell layer - Granule layer

Question 56

what structural layer of the cerebellar cortex has axons that projects outputs

Answer 56

Perkinjie layer

Question 57

what are the 3 fibers in basic cortical (cerebellar cortex) activity

Answer 57

- climbing fibers - mossy fibers - parallel fibers

Question 58

what do climbing fibers do

Answer 58

major cortical (cerebellar cortex) input from contralateral inferior olivary nucleus

Question 59

what do mossy fibers do ?

Answer 59

major cortical (cerebellar cotex) input from brainstem, vestibular system, and spinal cord

Question 60

where do climbing fibers synapse

Answer 60

on purkinje cels which regulates purkinje cell firing

Question 61

where do mossy fibers synapse

Answer 61

synapse on granule cells

Question 62

what connects the cerebellar cortex to deep nuclei

Answer 62

- collaterals from climbing and mossy fibers | - purkinje axons end on deep nuclei

Question 63

what are the 2 neuronal populations w/in the deep nuclei of the cerebellar cortex

Answer 63

- mossy fibers into cerebellar cortex | - output neurons leaving cerebellum

Question 64

what are the 3 functional subdivisions or longitudinal zones of the cerebllum from medial to lateral

Answer 64

1 - vestibulocerebellum 2 - spinocerebellum 3 - pontocerebellum

Question 65

the vestibulocerebellum is made up of what structural parts of the cerebellum

Answer 65

floculonodular lobe and part of vermis

Question 66

the spinocerebellum is made up of what structural parts of the cerebellum

Answer 66

paravermal area (medial hemisphere) and part of vermis

Question 67

the pontocerebellum is made up of what structural parts of the cerebellum

Answer 67

lateral hemisphere

Question 68

what is the input, output, and function of the vestibulocerebellum

Answer 68

input - vestibular organ/nuclei output - fastigal deep nuclei function - balance, control eye during head movements

Question 69

what is the input, output, and function of the spinocerebellum

Answer 69

``` input - brainstem and spinal cord output - interposed deep nuclei (emboliform and globose) function - coordinate trunk/limb movements ```

Question 70

what is the input, output, and function of the pontocerebellum

Answer 70

input - basilar pons and MCP (motor cortex) output - dentate deep nuclei function - planning timing movements (upper arm) and coordinate speech

Question 71

once the spinocerebellum recieves inputs at the interposed nuclei, where does it relay the message to ?

Answer 71

Red nucleus -----> VA/VL of thalamus ---> limb area of primary motor cortex

Question 72

once the pontocerebellum recieves inputs at the denate nucleus, where does it relay the message to ?

Answer 72

red nucleus ---> VA/VL of thalamus ----> all motor cortex and parietal lobe

Question 73

what is the function of the lateral hemisphere of the cerebellum

Answer 73

planned timing/skillful movements that get better w/practice

Question 74

what is the function of the medial hemisphere of the cerebellum

Answer 74

adjusting/coordinating limb movements

Question 75

what is the function of the vermis

Answer 75

postural adjustments (balance)

Question 76

what deep nuclei does the vermis project to ?

Answer 76

fastigal

Question 77

what deep nuclei does the medial hemisphere project to

Answer 77

interposed nuclei (emboliform and globose)

Question 78

what deep nuclei does the lateral hemisphere project to

Answer 78

dentate

Question 79

the principal OUTPUT from cerebellar nuclei is via

Answer 79

SCP

Question 80

The left side of the cerebellum projects to _______ side of the thalamus

Answer 80

right (contralateral )

Question 81

Left half of the cerebellum influences ______ limbs

Answer 81

Left (ipsilateral)

Question 82

Right cerebral hemisphere controls ______ muscles

Answer 82

Left (contralateral)