Test 2: Brainstem Motor Nuclei Flashcards
What is the difference between somatic vs branchial?
Based on embryonic origin- somatic is mesoderm origin of head/eye muscles/tongue
Somatic:
I, II, III, IV, VI, XII
Branchial:
V, VII, IX, X, XI
What 3 cranial nervse are not part of the corticobulbar system?
CN III, IV, VI
target eye muscles
CN V
CB, CB location, and target
Trigeminal motor
Pons
Muscles of mastication
CN VII
CB, CB location, and target
facial motor
pons
muscles of expression
CN IX
CB, CB location, and target
ambiguus
medulla
stylopharyngeal muscles
CN X
CB, CB location, and target
ambiguus
medulla
pharynx, largynx muscles
CN XI
CB, CB location, and target
Accessory motor
medulla/cervical
traps, SCM
CN XII
CB, CB location, and target
Hypoglossal
medulla
tongue
What do the brainstem visceromotor neurons do
all parasympathetic controlled
have pre ganglionic and post ganglionic CB that go to smooth muscles and glands
CN III visceromotor
Pregang, CB, post gang, and target
Ed-west
midbrain
ciliary
ciliary muscles and pupilary constrictors
CN VII to pterygodal
Pregang, CB, post gang, and target
superior salvitory nucleus
pons
pterygodal
lacrimal and nasal mucous
CN VII to submandibular
Pregang, CB, post gang, and target
superior salvitory nucleus
pons
submandibular
salivary gland
CN IX
Pregang, CB, post gang, and target
inferior salivary nucleus
pons/medulla
otic
parotid gland
CN X
Pregang, CB, post gang, and target
dorsal motor nucleus
rostral medulla
terminal
heart, lung, GI
What is the general pathway of corticobulbar tracts?
M1- through corona radiata- post limb - genu
Descend through midbrain ventrally by cereb pedunc
-start branching in pons down to spinal cord bilatearlly or one direction to different motor nuclei
Where is the trigeminal motor nucleus (V)
rostral/mid pons
- goes bilateral for facial control
- more contralateral
Where is the facial motor nucleus (VII)?
basis pons
- has upper and lower facial portions
- primarily contrlateral
Where is the hypoglossal motor nucleus (XII)?
medulla
- controls tongue
- more contrlateral
Where is the nucleus ambiguus (CN IX, X, sometimes XI)?
spans medulla
- primarily contrlateral
- tongue, phary/lary muscles
Where is the accessory nucleus (XI)?
medulla/cervical spine
- SCM/traps control
- primarily ispilateral
In the brainstem which motor nuclei sit medial to lateral?
Somatic most medial (except ed-west medial between III)
Broncomotor latearl to somatic
Visceral motor latearl to bronchomotor (except ed-west)
What branch of trigeminal nerve has brainstem nuclei control of motor function?
V3 manidbular branch
-small branchial motor divison
Controls:
jaw closers, openers for massication
middle ear to decrease chew sounds
Where is the CB for the trigeminal nerve
trigeminal motor nucleus
What is the ONLY branchial motor muscle with muscle spinlde
Jaw closers!
proprioceptive control for jaw stretch reflex
Where is the CB for the jaw closer stretch reflex of trigeminal?
trigeminal mesencephalic nucleus
What is the blood supply to the trigeminal motor nucleus
basilar and AICA
What is the main branch primary function of the facial nerve (VII)?
controlling facial expression
- lesser branches to jaw openers, middle ear, etc.
- muscles are derived from bronchiol arches and anchored to bone/fascia of the skin
Where are the motor neurons for the facial nerve?
facial nucleus in caudal pons
What do the motor neurons of the facial nucleus do in the caudal pons?
loop around the abducens nucleus
-creates bulge on the floor of 4th ventricl
What are the 5 branches of regional control for facial motor
- temporal
- zygomatic
- buccal
- mandiublar
- cervical
What is the path of the eye blink reflex?
temporal/zygomatic branches of facial control used!!
free nerve ending from trigeminal innvervation of cornea-> trigeminal tanglia -> spinal trigeminal tract -> caudal spinal trigeminal nucleus
reflex part goes up to facial nucleus- out to blink obicularis oculi
What does the glossopharybgeal (IX) do? where is the neuron
elevate pharynx: speech, swallow, gag
-neurons rostral nucleus ambiguus
What does vagus (X) do? where is neurons
innervates pharygneal muscles: swallow, gag, laryngeal muscles for smeepch
-neurons in rostral nucleus ambiguus
What does the accesory (XI) do? Where is it located?
SCM, traps
motor neurons from C1-C3
-spinal extension of ambiguus
What connects nucleus ambiguus and spinal accessory nucleus?
larygneal motor neurons in medulla/SC
What does the hypoglossal (XII) do? Where is it located?
intrinsic tongue muscles
hypoglossal nucleus in midline rostrall medulla
What is the path of the swall/gag control?
touch to back wall of throat sets of:
Superior ganglia of IX glossopharyngeal-> caudal solitary tract-> caudal solitary nucleus
synapse in solitary nucleus and sends signal to:
ambiguus nucleus and hypoglossal nucleus
-to open mouth, close pharynz, and thrust tongue
Where are the CB for preganglionic neurons in paraympathetic divisions?
Brainstem
Where are the CB for postganclionic neurons in parasympathetic divisions?
close to targets in head/pelvis
Where are the CBs for CNIII visceromotor
pregan: Ed-West
CB: ciliary gang
post: constrictor cilliary muscle
Where are the CBs for CNIV visceromotor
pre: superior salicary nucleus (pons)
CB: pterygoid or submandibular
Post: lacrimal, nasal, etc.
Where are the CBs for IX visceromotor
pre: inferior salivary nucleus (pons-med)
CB: otic
Post: salicary glands
Where are the CBs for X visceromotor
pre: dorsal motor nucleus of vagus
CB: terminal ganglia
post: heart, lung, GI
What is the main blood supply to the pons
AICA and basilar
What is the main blood supply to the medulla
PICA (lateral)
vertebral (anterior)
