(I) Reticular Formation: Motor And Autonomic Functions

Front 1

what part of the brainstem has few histologically distinct nuclei thats critical for almost all motor and vegetative functions of the nervous system and regulation of arousal?

Back 1

Reticular formation

Front 2

where do the afferents of the reticular system come from?

Back 2

sensory systems, cortex, hypothalamus, and thalamus
-integrative role of reticular formation

Front 3

what are the three groupings that the reticular formation can be divided into?

Back 3

midline raphe nuclei
medial columns
lateral columns

Front 4

what are the functions of the midline raphe nuclei of the reticular formation?

Back 4

primarily serotonergic
containing large neurons involving descending pain modulation, and in ascending activating systems

Front 5

what are the functions of the medial columns of the reticular formation?

Back 5

contains primarily large efferent neurons including those of reticulospinal tract

Front 6

what is the function of the lateral columns of the reticular formation?

Back 6

contains primarily parvocellular neurons that serve to relay somatic and visceral sensory information from ALS, trigeminal, and solitary nucleus to influence reticular formation efferent pathways

Front 7

where are the visceral integrating centers found in the reticular formation?

Back 7

caudal pontomedullary reticular formation

Front 8

what is the function of the visceral integrating centers of the reticular formation?

Back 8

control of heart beat, blood pressure, respiration, GI, gentiurinary control, reflexive behaviors

Front 9

If the Pontomedullary reticular formation received bilateral damage what would be the prognosis of your paitent?

Back 9

DEATH

Front 10

where is the ascending reticular activating system located?

Back 10

Rostral Pontomesencephalic reticular formation

Front 11

If there is damage to the ascending reticular activating system what does this cause?

Back 11

Irreversible coma because this system turns on the activity of the forebrain

Front 12

what are the Cholinergic nuclei of the brainstem?

Back 12

Pedunculopontine and laterodorsal tegmental nuclei

Front 13

what are the Noradrenergic nuclei of the brainstem?

Back 13

Locus Coerulus
Lateral Tegmental Area of Medulla

Front 14

What are the Serotonergic nuclei of the brainstem?

Back 14

rostral raphe nuclei

Front 15

what region of the brainstem controls horizontal gaze?

Back 15

PPRF in pons

Front 16

what region of the brainstem controls vertical gaze?

Back 16

rostral midbrain and pretectal area

Front 17

where does modulation of pain occur?

Back 17

midbrain: PAG
pons & medulla: raphe nuclei

Front 18

what are the visceral integrating centers of the medulla?

Back 18

LIFE SUPPORT
control blood pressure, heart rate, and respiration
Sensory input via IX, & X to solitary nucleus (GVA)
Effectors in dorsal motor nucleus of vagus, nucleus ambiguus, and spinal cord

Front 19

where are the effectors of the visceral integrating centers located? what do they effect?

Back 19

Effectors: dorsal motor nucleus of X, nucleus ambiguus, spinal cord
DMN X: GVE to heart, lungs, and gut to splenic flexure

Front 20

what sensory information is relayed to solitary nucleus via IX and X?

Back 20

Solitary nucleus is GVA
-sensation from chemoreceptors and baroreceptors of carotid body and aortic arch information

Front 21

why is bilateral damage to the pontomedullary reticular formation life threatening?

Back 21

lead to respiratory arrest because this is where the life support centers are located
-Tonsil herniation can result in uncompensated increase in intracranial pressure and compress these essential medullary centers

Front 22

where does the pontine and medullary reticulospinal tract originate?

Back 22

in pontine and medullary medial reticular nuclei

Front 23

does the reticulospinal tract project contralateral or ipsilateral?

Back 23

ipsilateral

Front 24

what is the main function of the pontine and medullary reticulospinal tracts?

Back 24

exert influence on LMN controlling proximal limb extensors and trunk

Front 25

what tract is important for adjustments in posture and balance preceding and during voluntary movement, semi-automoatic movements involving coordination, and muscle tone?

Back 25

Reticulospinal tract

Front 26

why are hypertonicity and hyperreflexia observed following damage to UMN?

Back 26

this is because of loss of descending control of the reticulospinal tract

Front 27

If there is bilateral damage to the midbrain below the level of the red nucleus what will be observed in your patients?

Back 27

DECERBRATE rigidity
this is due to unopposed activation of extensors by reticulospinal and vestibulospinal tracts

Front 28

how does the reticular formation play a role in modulating brainstem reflexes?

Back 28

it acts as a relay between the sensory input and the efferent limb

Front 29

where do spinomesencephalic fibers project to?

Back 29

PAG

Front 30

where do the PAG neurons project to for modulation of pain?

Back 30

raphe nuclei (raphe magnus) which is a serotonergic nuclei

Front 31

where do the nucleus raphe magnus neurons project to for modulation of pain?

Back 31

Nucleus raphe magnus is serotonergic and GABAnergic it projects to the spinal cord dorsal horn

Front 32

where do raphe axons terminate? what is their function?

Back 32

Raphe axons terminate on primary afferent terminals, interneurons, and second order neurons in the dorsal horn of spinal cord
-primarily inhibitory with regard to nociceptive afferent information

Front 33

where do the chemoreceptors for blood oxygen, and pH of the lung project to? why?

Back 33

directly and indirectly project through the solitary nucleus to medullary and pontine reticular nuclei controlling respiration

Front 34

what are the nuclei of the dorsal respiratory group of involved in what part of respiration?

Back 34

INSPIRATION

Front 35

what are the subnuclei of the ventral respiratory group? when are they active?

Back 35

Botzinger complex: expiration
Pre-Botzinger complex: inspiration
Rostral ventral respiratory group: inspiration
Caudal ventral respiratory group: expiration

Front 36

what nuclei modulates respiration?

Back 36

Medial parabrachial Kolliker Fuse area

Front 37

if there is damage to medial parabrachial nucleus what does this cause?

Back 37

Apneustic breathing
(match it to a lesion in our packet)

Front 38

what lower motor neurons have inherent rhythms that drive resting patterns of respiration?

Back 38

C3, C4, C5 give rise to phrenic nerve innervating the diaphragm

Front 39

what brainstem nuclei must be coordinated for control of respiration?

Back 39

XII: tongue
IX X: pharynx and larynx
XI: SCM & trapezius
VII: nares

Front 40

what type of inputs mediate voluntary control over breathing and for regulation during talking, singing, playing a musical instrument?

Back 40

Cortical inputs

Front 41

in controlling blood pressure how is the information from the baroreceptors in the carotid sinus and aortic arch relayed to the brainstem?

Back 41

CN IX & X carry sensory information from these receptors to solitary nucleus
solitary nucleus shares information with lateral parvocellular reticular nuclei in the lateral column

Front 42

what activates baroreceptors in the aortic arch and carotid sinus?

Back 42

increased blood pressure

Front 43

what are chemoreceptors sensitive to?

Back 43

oxygen, carbon dioxide, and blood pH

Front 44

describe the baroreceptor reflex

Back 44

1. PS neurons in inferior IX and nodose ganglia terminate in caudal solitary nucleus
2. solitary nucleus projects to control centers in medullary reticular formation and preganglionic neurons in nucleus ambiguus
3. Increased arterial pressure results in slowing of heart rate (X) and vasodilation (PS activation & sympathetics inhibition)

Front 45

why does damage to the spinal cord result in spinal shock with reduced blood pressure?

Back 45

lesioning of descending hypothalamospinal pathway

Front 46

what type of drug is useful in controlling blood pressure?

Back 46

Adrenergic antagonist

Front 47

what part of the reticular formation controls GI and genitourinary function?

Back 47

Pontine micturtion center

Front 48

what type of coordination does coughing require?

Back 48

coordination between nucleus ambiguus to prevent inspiration of irritant

Front 49

what type of coordination does sneezing require?

Back 49

involves coordination with n. ambiguus and facial n.

Front 50

what are hiccups caused by?

Back 50

involuntary inspiration caused by spasm of the diaphragm

Front 51

what is the sound of a hiccup caused by?

Back 51

rapid closing of vocal cords

Front 52

what can cause intractable hiccups?

Back 52

damage to medullary reticular formation

Front 53

what is the pseudobulbar affect?

Back 53

emotional incontinence

Front 54

If a patient is suffering from pseudobulbar affect, what might be the symptoms and what caused this?

Back 54

abnormal reflex activation of circuits for laughter and crying
-lesions of descending pathways or brainstem centers

Front 55

True or False
The act of smiling is both voluntary and non-voluntary.

Back 55

True
there is a reflexive smile and a voluntary smile
a patient may still be able to smile in response to a joke if they have a corticobulbar lesion contralateral voluntary paralysis of lower face because the facial nerve is still intact and muscles can be activated by the limbic pathways