RETICULAR FORMATION Flashcards

1
Q

Mass of neurons and nerve fibers extending from caudal medulla to rostral midbrain and continuous with subthalamus and midline,
intralaminar and reticular nuclei of the thalamus

A

RETICULAR FORMATION
‘reticular’ = ‘net’ of neurons

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2
Q

Located in brainstem tegmentum and comprises a neural system with multiple inputs and multiple synaptic system of impulse conduction

A

RETICULAR FORMATION

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3
Q

Strategically placed among important nerve
tracts and nuclei

Receives input from most sensory systems and
sends efferent fibers to all parts of CNS levels

Influence skeletal muscle activity, somatic and
visceral sensation, ANS and endocrine systems
as well as level of consciousness

A

RETICULAR FORMATION

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4
Q

Recite THE GENERAL ARRANGEMENT of reticular formation

A

● Deeply placed continuous network of nerve cells
and fibers extending from brainstem, towards
subthalamus, hypothalamus and thalamus

● Contains highly organized groups of
transmitter-specific cells that influence specific
CNS areas

● Polysynaptic

● 3 longitudinal columns:
1.Median column - at median plane;
intermediate-sized neurons; at center
2. Medial column - contains large neurons
3. Lateral column - small neurons

● Inferiorly, continuous with interneurons of gray
matter of spinal cord

● Superiorly, impulses are relayed to cerebral
cortex and cerebellum

● Continues into the diencephalon

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5
Q

TRUE or FALSEMedian group & paramedian are a separate entity

A

FALSE, are deemed as one

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6
Q

Name the 5 structures of the median groups (RETICULAR COLUMNS)

A

Superior Central, Raphe Pontis,Raphe Magnus, Raphe Pallidus, Raphe Obscurus

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7
Q

Name the 5 structures of the medial groups

A

RAPHE NUCLEI, reticularis pontis oralis, reticularis
pontis candalis, reticularis gigantocellularis

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8
Q

Name the 5 structures of the lateral groups

A

cuneiform and subcuneiform
nuclei, pedunculopontine, parabrachial,
reticularis pervocellularis, reticularis lateralis

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9
Q

________ of medulla receive inputs from
spinal cord, trigeminal sensory nuclei and
periaqueductal gray matter of the midbrain;
project to cerebellum, dorsal horn of spinal cord
and trigeminal nuclei

A

Raphe Nuclei

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10
Q

Facilitatory input from the periaqueductal gray
matter to medullary raphe nuclei and its
inhibitory projections on spinothalamic neurons
in dorsal horn of spinal cord. What will be produced?

A

ANALGESIC EFFECT. Thus, inhibiting raphe nuclei and will produce less pain

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11
Q

receive inputs from prefrontal cortex, limbic
system and hypothalamus and project widely to
forebrain, cerebellum and brainstem

A

Raphe nuclei of rostral pons and midbrain

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12
Q

involved in pain
mechanisms

A

Caudal raphe nuclei

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13
Q

involved with
wakefulness, alertness and sleep

A

Rostral raphe nuclei

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14
Q

● Receives inputs from spinal cord, cerebral
cortex, vestibular nuclei
● Project to cerebellum

A

CONNECTIONS OF PARAMEDIAN GROUP

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15
Q

● Input from spinal cord, ascending sensory
systems, superior colliculus,
vestibulocerebellum, hypothalamus, and
cerebral cortex
● Descending projections project to spinal cord -
motor control
● Ascending projections to intralaminar nuclei of
the thalamus and basal cholinergic nuclei (aka
nucleus basalis of Meynert) - consciousness and
alertness is located in medial column
● Nucleus reticularis pontis caudalis - paradoxical
(REM, rapid eye movement) sleep; time when
deep sleep of a person happened, when we
dream

A

CONNECTIONS OF MEDIAL GROUP

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16
Q

● Lateral nuclei in medulla and pons
(parvocellularis and lateralis) constitute the
receptive components of reticular nuclei
● Pedunculopontine nucleus on rostral pons to
caudal midbrain

● Parabrachial nucleus on rostral pons to caudal
midbrain

A

CONNECTIONS OF LATERAL GROUPS

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17
Q

Continuation of reticular formation from
brainstem

Receives input from cerebral cortex and other
thalamic nuclei

A

RETICULAR NUCLEUS OF THALAMUS

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18
Q

Project it further to other thalamic nuclei; Integrating and gating thalamic nuclei activities

A

RETICULAR NUCLEUS OF THALAMUS

19
Q

Neurotransmitter of RETICULAR NUCLEUS OF THALAMUS

A

GABA

20
Q

○ Function with diencephalic nuclei to maintain
alert conscious state
○ Mainly for consciousness

A

Rostral reticular formation of the mesencephalon
and upper pons

21
Q

Work with CN nuclei and spinal cord to carry
out motor, reflex and autonomic functions

A

Caudal reticular formation of pons and medulla

22
Q

Neuromodulatory cholinergic neurons
with widespread projections at: Pontomesencephalic region of brainstem and Basal Forebrain

A

Acetylcholine

23
Q

It is the pedunculopontine tegmental nuclei and
laterodorsal tegmental nuclei

○ Travel to thalamus, including intralaminar
nuclei, which project to cerebral cortex
○ These nuclei have extensive connections
with basal ganglia, tectum, cerebellar nuclei

A

Pontomesencephalic region of brainstem

24
Q

aka Nucleus basalis of Meynert

■ Project to almost entire cerebral cortex
○ Medial septal nuclei and nucleus of the
diagonal band of Broca to hippocampal
formations

■ Memory

A

Basal Forebrain

25
Q

● Located mainly in ventral midbrain
● Substantia nigra pars compacta
● Ventral tegmental area
● 3 projection systems:
Mesostriatal
Mesolimbic
Mesocortical

A

Dopamine

26
Q

from
substantia nigra pars compacta projecting to
caudate and putamen; for movement

A

Mesostriatal

27
Q

from ventral tegmental area
projecting to limbic structures medial
temporal cortex, amygdala, cingulate gyrus
and nucleus
○ Overactivity: hallucinations

A

Mesolimbic

28
Q

mainly from ventral
tegmental area projecting to prefrontal cortex
○ Function: working memory, attentional
aspects of motor initiation
○ Dysfunction: cognitive deficit and
hypokinesia in Parkinson’s Disease

A

Mesocortical

29
Q

-found in Lateral tegmental area of pons and medulla
along with Locus Ceruleus, which is found in
substantial feruginea
○ “blue spot”
○ Near the 4th ventricle in rostral pons

Functions of ascending norepinephrine
projection system:

○Modulation of attention, sleep wake states and mood

A

Norepinephrine (Noradrenaline)

30
Q

● secreted by Raphe nuclei of brainstem
○ Rostral raphe nuclei of rostral pons and
midbrain - project to entire forebrain,
including cortex, thalamus and basal ganglia
■ imp for wakefulness & consciousness
○ Caudal raphe nuclei of caudal pons and
medulla - for pain modulation, breathing,
temperature regulation and motor control
● Sleep, emotion

A

Serotonin

31
Q

● Found in neurons of posterior hypothalamus in
tuberomammillary nucleus
● Maintain alert state
● If u take anti-histamine, you’ll be sleepy w/o
histamine

A

Histamine

32
Q

What are the motor and autonomic System?

A

Respiration, Heart rate and BP, Coordinating activity and mediating reflexes, Coughing, hiccupping, sneezing, yawning, shivering
gagging, vomiting, swallowing, laughing, crying

33
Q

Respiratory rhythms occur automatically under
control of ___________

A

medullary circuits

34
Q

_______ can temporarily control voluntary breathing

A

Forebrain

35
Q

pacemaker for
respiration; located in medulla

A

Pre-BÖtzinger complex

36
Q

All nuclei project to __________ to
control phrenic nerve and thoracic levels for
thoracic inspiratory and expiratory muscles

A

C3-C5 spinal segments

37
Q

Nucleus solitarius and Presympathetic neurons in rostral ventrolateral
medulla project to sympathetic neurons intermediolateral cell column of spinal cord

A

these neurons have Connections to limbic system, hence BP & HR responds to our
emotions & homeostasis

38
Q

involving the cranial nerve nuclei - corneal reflex, eye movements

A

Coordinating activity and mediating reflexes

39
Q

Located along caudal lateral
wall of the fourth ventricle in medulla; center for Nausea and vomiting

A

Area Postrema

40
Q

Maintain sphincter control

A

Pontine Micturition Center

41
Q

Where are afferent projections coming from:

A

From the spinal cord, cranial nerve nuclei, cerebellum, diencephalon, corpus striatum, limbic system, primary motor and somatosensory cortex.

42
Q

Where are efferent projections coming from:

A

Reticulobulbar tract, Reticulospinal tract, Autonomic nervous system, Corpus striatum, Cerebellum, Red nucleus, Substantia nigra, Tectum, Diencephalic nuclei and cerebral cortex

43
Q

FUNCTIONS OF THE RETICULAR FORMATION

A

● Control of skeletal muscles
● Control of facial expressions
● Control of somatic and visceral sensations
● Control of ANS
● Control of endocrine system
● Influence of biologic clocks
● Reticular activating system