reticular formation

Question 1

The ___ is a phylogenetically old, central core of the brainstem, which extends into the cerebrum as the ___.

Answer 1

• reticular formation

- hypothalamus

Question 2

What functions are the RF important for

Answer 2

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

Question 3

3 zones of RF

Answer 3

1. Raphe (median) nuclei
2. Medial zone
3. Lateral zone

Question 4

Why is the Medial zone significant?

Answer 4

• source of most ascending and descending projections

Question 5

Where is the lateral zone most prominent and what is its function?

Answer 5

• Prominent in the rostral medulla and caudal pons

- Primarily involved in cranial nerve reflexes and visceral functions

Question 6

Which two reticulospinal tracts serve as major alternative to corticospinal tracts in regulating spinal reflexes?

Answer 6

• Medial
• Lateral
• Only noxious stimuli to evoke a reflex

Question 7

The reticulospinal tract neurons receive input from the ___, ___, ___.

Answer 7

• cerebral cortex
• basal ganglia
• substantia nigra

Question 8

The ___ begins in the pons ipsilaterally, descends near the MLF and in the anterior funiculus. It facilitates ___ movements and ___ muscle tone.

Answer 8

• Medial tract
• voluntary movements
• increases

Question 9

The ___ is found in the medulla, descends bilaterally in the lateral funiculus, and ___ voluntary movements, and ___ muscle tone.

Answer 9

• lateral tract
• inhibits
• decreases

Question 10

Name the rhythmic motor patterns in the brainstem reticular formation.

Answer 10

1. gaze centers
2. mastication (supratrigeminal nucleus in pons)
3. locomotion (pons)
4. heart rate
5. respiration
6. swallowing/vomiting

Question 11

Malocclusion results in premature and one sided contact of teeth, jaw movements continue in an attempt to reach resting position is which theory of bruxism?

Answer 11

peripheral causes theory (based on clinical observation)

Question 12

Sleep-related dysfunctions, input to supratrigeminal nucleus may be from BG, lateral hypothalamus, and central nucleus of amygdala relates to which theory of bruxism?

Answer 12

central causes theory

Question 13

RF, especially the ___ can suppress or facilitate pain depending on the circumstances.

Answer 13

Periaqueductal grey (PAG)

Question 14

Sensory information from the ___ reaches the PAG as spinomesencephalic fibers

Answer 14

anterolateral pathway

Question 15

The PAG also receives input from the ___, ___, and ___ which may contain behavioral state info letting the body know whether pain should be activated or suppressed.

Answer 15

• hypothalamus
• cortex
• amygdala

Question 16

The PAG sends signals to the ___ which send signals to the ___.

Answer 16

• raphe

- posterior horn of the spinal cord (afferents)/spinal V nucleus

Question 17

The ___, is responsible for sleep-wake cycles, thus mediating various levels of alertness.

Answer 17

• Ascending reticular formation (AKA reticular activating system)

Question 18

The ___ is involved in posture and equilibrium as well as ___.

Answer 18

• Descending reticular formation

- autonomic nervous system activity

Question 19

The descending reticular formation also plays a role in ___.

Answer 19

motor movement

Question 20

How do opiates suppress pain in the RF?

Answer 20

• work by activating the PAG-raphe at multiple levels.

- Opiate receptors are abundant in the PAG, rap he, and posterior horn of the spinal cord.

Question 21

___ can inhibit the STT directly, or indirectly by activating interneurons that inhibit the STT.

Answer 21

Raphe

- (STT= sensory from the skin the thalamus)

Question 22

The RF has centers controlling inspiration, expiration and rhythm of breathing in the __ and __.

Answer 22

pons and medulla

Question 23

Heart rate and BP control centers are found in the ___

Answer 23

medulla

Question 24

Where do we find norepinephrine receptors?

Answer 24

• lateral zone of brainstem (rostral medulla and rostral pons)

Question 25

Were do we see dopamine and serotonin receptors?

Answer 25

Median raphe of the brainstem

Question 26

Where are histamine containing neurons found?

Answer 26

Hypothalamus

Question 27

Where do we find acetylcholine receptors?

Answer 27

- telencephalon and pons

Question 28

Where is the Solitary nucleus found, and what type of receptors are located here?

Answer 28

- found in the posterior aspect of the medulla and is a receptor for norepinephrine - functions in memory enhancement

Question 29

Where is the Locus ceruleus located, and what type of receptors are located here?

Answer 29

- found in the posterior aspect of the rostral pons | - functions in cortex (arousal) vigilance and attention

Question 30

Norepinephrine is also found in the ventrolateral medulla, and is used as a ___.

Answer 30

pain regulator

Question 31

Norepinephrine released in the trigeminal spinal nucleus and spinal cord is used to ___.

Answer 31

suppress incoming pain signals.

Question 32

Noradrenergic projections innervate practically the entire CNS; they have heavy projections to the ___.

Answer 32

somatosensory cortex

Question 33

___ levels of norepinephrine can lead to clinical depression

Answer 33

decreased

Question 34

Decreased levels of norepinephrine lead to reduced ___ activity

Answer 34

locus ceruleus neuron

Question 35

___ patients often suffer from depression due to the fact that the locus ceruleus neurons are lost.

Answer 35

Parkinsons

Question 36

___ is caused by an increase in norepinephrine levels.

Answer 36

Panic disorder

Question 37

Dopaminergic neurons are found in the midbrain and include the ___, and ___.

Answer 37

- Substantia Nigra (putamen and caudate) | - Ventral tagmental area

Question 38

The ___ is involved in motor activity, and can be affected in patients with Parkinson's.

Answer 38

Substantia nigra

Question 39

The ___ is the major source of dopamine and contains two tracts.

Answer 39

Ventral tegmental area (limbic system)

Question 40

What are the two tracts of the ventral tegmental system?

Answer 40

1. Mesocortical tract/fibers | 2. Mesolimbic tracts/fibers

Question 41

What is the purpose of the mesocortical tract?

Answer 41

- Responsible for organized thinking and planning | - sends heavy projections to frontal cortex which organize and initiate behaviors

Question 42

Whats the purpose of the mesolimbic tract?

Answer 42

It is involved in emotional reward and drug dependency.

Question 43

___ is involved in social withdrawal due to low levels of dopamine in the prefrontal cortex.

Answer 43

Schizophrenia

Question 44

___ occur due to high levels of dopamine in the limbic system.

Answer 44

Hallucinations

Question 45

Serotonergic neurons are located at pretty much all brainstem levels in ___.

Answer 45

raphe

Question 46

Raphe nuclei in the ___ send signals to all regions of the ___ and are used for attention inhibition of distracting stimuli.

Answer 46

- midbrain | - cortex

Question 47

___ raphe nuclei send information to the ___ with regards to day night cycle.

Answer 47

- Midbrain | - hypothalamus

Question 48

___ raphe nuclei send signals to the ___ in pain suppression. More specifically this is done by the ___.

Answer 48

- medullary raphe - spinal cord - nucleus raphe magnus

Question 49

Serotonergic neurons can also cause clinical depression through ___.

Answer 49

Selective serotonin reuptake inhibitors (SSRI)

Question 50

Low levels of ___ can be a result of high carb intake, binge eating, or carb preference in obese women.

Answer 50

serotonin

Question 51

High levels of serotonin can lead to compulsive behavior and ___.

Answer 51

anorexia nervosa

Question 52

Chlolinergic neurons are found in the ___.

Answer 52

basal forebrain; basal nucleus of Meynert

Question 53

___ is a disease dealing with ACh

Answer 53

Alzheimers (drug treatment; cholinesterase inhibitors)