Week 5: Reticular Formation Flashcards
Identify the major anatomical structures (nuclei/neurons and areas) of the Reticular formation system.
- the precerebellar nuclei
- the raphe nuclei
- the central group of nuclei
- the cholinergic and catecholamine cell groups,
- the lateral parvocellular reticular area,
- the parabrachial area, and
- the superficial medullary neurons.
Identify the major functions of the reticular formation systems.
– the sleep–arousal cycle
– perception of pain
– control of movement, and
– regulation of visceral activity
Which of the following is part of the reticular formation?
a. the nuclei of the cranial nerves
b. the central group of nuclei
c. conspicuous masses of gray matter
d. the long tracts that pass through the brain stem
e. the nucleus ambigus
f. the medial lemniscus
b. the central group of nuclei
The component parts of the reticular formation are
distinct. List seven aggregations of neurons that are recognized as reticular formation nuclei.
- the precerebellar nuclei
- the raphe nuclei
- the central group of nuclei
- the cholinergic and catecholamine cell groups,
- the lateral parvocellular reticular area,
- the parabrachial area, and
- the superficial medullary neurons.
The lateral reticular nucleus, paramedian reticular nucleus and the pontine reticulotegmental nucleus form the:
a. the precerebellar nuclei
b. the raphe nuclei
c. the cholinergic and catecholamine cell groups
d. the lateral parvocellular reticular area
e. the parabrachial area
a. the precerebellar nuclei
The component parts of the reticular formation are distinct. List seven aggregations of neurons that are recognized as reticular formation nuclei.
- the precerebellar nuclei
- the raphe nuclei
- the central group of nuclei
- the cholinergic and catecholamine cell groups,
- the lateral parvocellular reticular area,
- the parabrachial area, and
- the superficial medullary neurons.
Many raphe neurons
synthesize and secrete:
a. GABA
b. Catecholamines
c. Dopamine
d. serotonin (5-hydroxytryptamine)
e. Glutamate
f. ACh
d. serotonin (5-hydroxytryptamine)
Which of the following is CORRECT regarding raphe nuclei?
a. Their are mostly uncrossed
b. The axons of the serotonergic raphe neurons are thin, unmyelinated, and greatly branched.
c. The more caudally located raphe nuclei
play significant role in sleep.
d. Many raphe neurons
synthesize and secrete dopamine which is their principal synaptic transmitter.
e. These are groups of neurons are located caudally in the dorsolateral part of the brainstem
b. The axons of the serotonergic raphe neurons are thin, unmyelinated, and greatly branched.
CORRECTIONS They are interspersed among bundles of decussating axons. The more rostrally located raphe nuclei play significant role in sleep. These are groups of neurons either in or adjacent to the midline (raphe) of the brain stem.
Which of the following is CORRECT regarding the gigantocellular reticular nucleus?
a. Does not include serotonin neurons
b. It is laterally located
c. It has visceral function, including maximal inspiration
d. It is a cholinergic nuclei
c. It has visceral function, including maximal inspiration
Some neurons in the brain stem and hypothalamus actively promote sleep. Which of the following are active in deep (non-REM) sleep?
a. The central group of reticular nuclei
b. The accessory oculomotor nuclei
c. Noradrenergic neurons
d. The serotonergic raphe neurons
e. the interstitial nucleus of Cajal
d. The serotonergic raphe neurons
Activity of which pathway can suppress the conscious awareness of pain?
a. medullary raphe nuclei with the periaqueductal gray matter and the spinal dorsal horn
b. the lateral reticular nucleus with the cerebellum
c. the reticulospinal tracts
d. the central group of reticular nuclei travelling in the central tegmental tract
e. cholinergic neurons and the central group of pontine reticular nuclei
a. medullary raphe nuclei with the periaqueductal gray matter and the spinal dorsal horn
The reticulospinal tracts, located in the ventral and lateral funiculi of the spinal white matter, are formed by the long descending axons of which nuclei?
a. the raphe nuclei
b. the precerebellar reticular nuclei
c. cholinergic reticular nuclei
d. the central group of reticular nuclei
e. catecholaminergic neurons
d. the central group of reticular nuclei
Which of the following is NOT true regarding the central group of reticular nuclei?
a. Includes the PPRF and gigantocellular reticular nuclei
b. Includes the cuneiform and subcuneiform nuclei
c. Electrophysiological studies implicate these nuclei in stereotyped motor functions, such as locomotion
d. PPRF involved in conjugate lateral movements of the eyes
e. Neurons of the central reticular nuclei typically have axons with long ascending and descending branches.
c. Electrophysiological studies implicate these nuclei in stereotyped motor functions, such as locomotion
This is true of cholinergic neurons
The pontine and mesencephalic raphe nuclei send projections to:
a. the spinal cord, cranial nerve nuclei and the intralaminar thalamic nuclei
b. the cerebellum and all parts of the cerebrum
c. the cerebellum, cerebral cortex and thalamus
d. the cerebellum
b. the cerebellum and all parts of the cerebrum
Which of the following contains neurons whose patterns of firing follow a 24-hour cycle serve as an internal clock for
the brain?
a. The lateral hypothalamus
b. . The serotonergic raphe neurons
c. The cholinergic neurons of the pedunculopontine and lateral dorsal tegmental nuclei
d. GABA-ergic neurons
e. The suprachiasmatic nucleus of the hypothalamus
e. The suprachiasmatic nucleus of the hypothalamus
Which of the following is CORRECT regarding the cholinergic neurons of the pedunculopontine and lateral dorsal tegmental nuclei?
a. These nuclei are as active in REM sleep as they are in the awake state.
b. They use dopamine as their synaptic transmitter
c. Damage to these neurons is associated with visual abnormalities
d. The pedunculopontine is the smaller of the two nuclei
e. These neurons have short, branching axons
a. These nuclei are as active in REM sleep as they are in the awake state.
Corrections
The pedunculopontine is the largest
Use ACh
have long, branching axons
The parvocellular reticular nuclei/neurons are located in:
a. the medulla
b. the medulla and pons
c. the midbrain
d. the midbrain and pons
e. the pons
b. the medulla and pons
Where do the axons of parabrachial neurons project rostrally to?
- the hypothalamus
– preoptic area
– intralaminar thalamic nuclei, and
– amygdala.
The precerebellar nuclei send projections to:
a. the spinal cord, cranial nerve nuclei and the intralaminar thalamic nuclei
b. the cerebellum and all parts of the cerebrum
c. the cerebellum, cerebral cortex and thalamus
d. the cerebellum
d. the cerebellum
The superficial medullary neurons are concerned with what function?
a. movements of the eyes
c. the poorly localized perception of pain
c. modulation of pain
sensation
d. sleeping and awake states
e. cardiovascular and respiratory regulation
e. cardiovascular and respiratory regulation
The fibers of this region are activated by
– the baroreceptors of the carotid and aortic sinuses and
– the oxygen-sensitive chemoreceptors of the carotid and aortic bodies.
Some of these medullary neurons respond directly to changes in the pH or carbon dioxide concentration.
The central group of reticular nuclei forms part of an ascending pathway (through spinal afferents and projections to the thalamus) for which function?
a. movements of the eyes
c. the poorly localized perception of pain
c. modulation of pain
sensation
d. sleeping and awake states
e. cardiovascular and respiratory regulation
c. the poorly localized perception of pain
The “pneumotaxic center,” (the region concerned with the regulation of respiratory rhythm) is thought to be in which aggregations of neurons?
PARABRACHIAL AREA
The parvocellular reticular nuclei/neurons are: (Select all that apply)
a. involved in reflexes which are concerned with feeding
b. a relay station in ascending pathways for visceral sensations
c. activated by the baroreceptors of the carotid and aortic sinuses
d. lateral to the central group and medial to the trigeminal nuclei.
e. located in the medulla and pons
a. involved in reflexes which are concerned with feeding
d. lateral to the central group and medial to the trigeminal nuclei.
e. located in the medulla and pons
CORRECTIONS:
b. a relay station in ascending pathways for visceral sensations - applies to PARABRACHIAL AREA
c. activated by the baroreceptors of the carotid and aortic sinuses - applies to SUPERFICIAL MEDULLARY RETICULAR NEURONS
Which of the following is CORRECT regarding the catecholamine nuclei
a. They use acetylcholine as their synaptic transmitter.
b. Destructive lesions of the locus coeruleus cause unconsciousness.
c. Neurotransmitter released by axons
from the locus coeruleus and related cell groups probably acts mainly as a
modulator of synapses between other neurons.
d. Some provide an ascending projection that inhibits neurons throughout the cerebral cortex.
e. they are more active in non-REM sleep and REM sleep.
c. Neurotransmitter released by axons
from the locus coeruleus and related cell groups probably acts mainly as a
modulator of synapses between other neurons.
CORRECTIONS:
They use noradrenaline (norepinephrine), adrenaline (epinephrine), and dopamine
Destructive lesions of the locus coeruleus do not cause unconsciousness.
provide an ascending projection that excites neurons throughout the cerebral cortex.
they are less active in non-REM sleep and inactive in REM sleep.
The central group of reticular nuclei send projections to:
a. the spinal cord, cranial nerve nuclei and the intralaminar thalamic nuclei
b. the cerebellum and all parts of the cerebrum
c. the cerebellum, cerebral cortex and thalamus
d. the cerebellum
a. the spinal cord, cranial nerve nuclei and the intralaminar thalamic nuclei
Where do the neurons in the parvocellular reticular area send their axons to?
the motor nuclei of the
hypoglossal, facial, and
trigeminal nerves.
