Brainstem Nuclei Flashcards
Which cranial nerve does the mesencephalic nucleus V innervate?
CN V, trigeminal V3 (mm of mastication)
Which cranial nerves does the principal/chief nucleus V innervate?
CN V, trigeminal V1-V3
Which cranial nerve dies the spinal trigeminal nucleus V?
CN V, trigeminal - pain and temp of face and neck / touch of anterior 2/3 tongue / cornea
CN IX, glossopharyngeal - pharynx and esophagus / post 1/3 tongue
CN X, vagus - pharynx, larynx, esophagus
Which cranial nerve does the vestibulocochlear nucleus innervate?
CN VIII, vestibulocochlear nerve - balance and audition
Which cranial nerve does the NTS innervate?
rostral:
- CN VII, facial - taste and 2/3 tongue
- CN IX, glossopharyngeal - taste post 1/3 tongue
caudal:
- CN IX, glossopharyngeal - baroR and chemoR
- CN X, vagus - GVA of entire abdomen
Which nucleus innervates general sensory afferents? Which cranial nerves does it innervate
trigeminal nucleus
GSA: V, VII, IX, X
Which nucleus innervates general visceral afferents? Which cranial nerves does it innervate?
NTS
GVA: VII (taste), IX
Which nucleus innervates special sense? Which cranial nerve does it innervate?
vestibulocochlear nucleus
special sense: VIII
Which nuclei innervate general somatic efferents? Which cranial nerves do they innervate?
- oculomotor nucleus: III
- trochlear nucleus: IV
- abducens nucleus: VI
- hypoglossal nucleus: XII
Which nuclei innervate general visceral efferents? Which cranial nerves do they innervate?
- EW nucleus: III
- superior salivary nucleus: VII
- inferior salivary nucleus: IX
- DMV nucleus: X
Which nuclei innervate the branchiomotor column?
- trigeminal nucleus: V
- facial motor nucleus: VII
- nucleus ambiguus: IX, X
- spinal accessory C1-C5: XI
What occurs at the decussation of the pyramids? Which section of the medulla does this occur in?
cross over of the descending tracts (motor) - in caudal medulla
What is the order from top to bottom?
caudal medulla, rostral medulla, closed medulla
- rostral medulla
- closed medulla
- caudal medulla
What occurs at the decussation of internal arcuate fibres? Which section of the medulla does this occur in?
crossover of ascending tracts (sensory) - in closed medulla
Which level of the medulla can be identified using the inferior olivary nucleus?
rostral (open) medulla
Which brainstem nuclei can be used to identify the caudal pons level?
abducens nucleus, facial nucleus, trigeminal motor nucleus
What feature can be used to identify the level of the mid-pons?
trigeminal nerve
What is the identifying feature of the rostral pons?
corticospinal and corticobulbar fibres
Where is mickey mouse found?
caudal midbrain
What is the identifying feature of the caudal midbrain?
inferior colliculus (and one-eyed mickey mouse)
What is the identifying feature of the rostral midbrain?
superior colliculus (and 2-eyed mickey mouse)
What are the major ascending tracts in the brainstem?
- dorsal columns/medial lemniscal pathway
- spinothalamic tract
- trigeminothalamic tract
What are the afferent tracts that pass through the inferior cerebellar peduncle?
- spinocerebellar tract
- cuneocerebellar tracts
- olivocerebellar tracts
- vestibulocerebellar tracts
What are the major descending tracts in the brainstem?
- corticospinal
- corticopontine
- corticobulbar
- vestibulospinal
- reticulospinal
- rubrospinal
What are the functions of the reticular formation?
- controlling arousal and consciousness
- maintain tone and posture (reticulospinal tracts)
- autonomic relays (respiratory, cardiac, visceral)
- perception of pain
TRUE or FALSE: reticular formation receives both afferent and efferent projections.
TRUE
What are the 3 main zones of the reticular formation?
- raphe nuclei (most medial)
- medial zone
- lateral zone
What are the nuclei of the reticular formation?
- raphe nuclei
- reticulospinal nuclei
- cholinergic
- catecholinergic
- nuclei for cardiorespiratory center
- nuclei for visceral sensations
Where do the raphe nuclei project to in the brain? Which NT is released in this system? What do the rostral projections affect? caudal projections affect?
project to: limbic system
NT: serotonergic
rostral projections affect: sleep patterns
caudal projections affect: afferents from PAG and pain perception
Which pathway do opiates act via?
pain perception pathway: caudal projections from raphe nuclei –> dorsal horn –> block pain perception from spinothalamic tract
What part of the reticular formation is found in the medial zone?
reticular activating system (RAS)
Is the RAS ascending or descending? What is its function? What happens when it is damaged?
- ascending
- promote arousal and consciousness
- damage –> unconsciousness
What does the lateral zone of the RF control? Describe the pathway. What happens when there is a lesion?
- control cardiorespiratory reflex
- pathway: CN IX (chemo/baroreceptors) –> NTS –> reticular zone respiratory centers (vagus efferent path) –> control breathing and HR
- lesion: unconsciousness/death
Which zones of the RF do reticulospinal tracts come from?
medial and lateral zones
Where do the reticulospinal tracts synapse?
directly onto LMNs in the spinal cord
What is another name for the medial reticulospinal tract? lateral?
medial = pontine reticulospinal tract
lateral = medullary reticulospinal tract
What does the pontine (medial) reticulospinal tract control?
excitatory to leg extensors and arm flexors (i.e. posture and balance)
What does the medullary (lateral) reticulospinal tract control?
inhibit all limb musculature especially during REM sleep
