Brain stem Flashcards
What part of the brainstem controls maintenance of consciousness?
Reticular formation
What are the gross anatomical features of the midbrain?
- Superior and inferior colliculi (corpora quadrigemina)
- Cerebral peduncles
- Cerebral aqueduct
What are the gross anatomical features of the pons?
- Basal pons
- Middle cerebellar peduncle
- Part of 4th ventricle
What are the gross anatomical features of the medulla?
- Pyramids
- Olives
- Part of 4th ventricle
What forms the floor of the posterior cranial fossa? Roof? What major brain divisions are found there?
- Occiput
- Tentorium cerebelli
- Cerebellum and brainstem
Where specifically are the corpora quadrigemina located?
Tectum of midbrain (dorsal)
The inferior colliculi are involved in _______, the superior colliculi are involved in _______.
Which deal with which nuclei?
- Hearing
- Vision
SLO AIM
- Superior colliculi, lateral geniculate, optic
- Auditory, inferior colliculi, medial geniculate
Where are the superior cerebellar peduncles?
Middle?
Inferior?
- Sup: midbrain
- Mid: pons
- Inf: medulla
Where are the cerebral peduncles located?
Midbrain
Where are the olives and what do they connect to?
- Medulla
- Connect to dentate nucleus of cerebellum
Where are the pyramids found and which tract are the pyramids a part of?
- Medulla
- CST (decussates into sc)
Describe the approximate location of the 4th ventricle.
Review: what are the names of the holes leading out of the 4th ventricle?
- B/w pons/upper medulla and cerebellum
- Lateral foramen of Lushka, posterior Midline foramen of Magendi.
What is the name of the thickest n. coming out of the pons?
Trigeminal n. (CN V)
Which is the only CN that leaves from the dorsal side of the brainstem?
What else does it uniquely do?
Trochlear n. (CN IV)
- Crosses
Which of the cerebellar peduncles is positioned most ventrally?
Middle cerebellar peduncle
What is the path of CN 11?
Enters thru foramen magnum, leaves thru jugular foramen
The pulvinar nucleus plays a role in _____________.
The mammillary bodies play a role in _____________.
- Vision
- Memory
(mammillary bodies connect to hippocampus via fornix and degenerate in severe alcoholism)
Where’s the red nucleus found?
Midbrain
At what specific brainstem level would you see internal arcuate fibers?
Caudal medulla
At what specific brainstem level would you see inferior olivary nucleus?
Rostral medulla
At what specific brainstem level would you first see the medial logitudinal fasciculus (MLF)?
What’s its function?
Immediately (caudal medulla)
- The MLF deals with coordinating the nuclei of 3, 4, and 6 with each other and spinal reflexes (coordinates head/neck/eye movements)
The deep cerebellar nuclei first become visible at what specific brainstem level?
Name them.
- Caudal pons
Fat guys eat doughnuts
- Fastigal, globose, emboliform, dentate
Any cell bodies seen in the pons are known as _________________.
Pontine gray nuclei
As you ascend the brainstem, where does the periaqueductal gray (PAG) begin, specifically?
Rostral pons (surrounds top of 4th ventricle)
In the brainstem, explain the general spatial arrangement of the DCP, STT, and CST.
- DCP medial (lemniscus)
- STT lateral (pain)
- CST ventral (pyramids)
Where do the superior cerebellar peduncles (SCPs) decussate, specifically?
Caudal midbrain (makes sense)
Ascending the brainstem, where is the cerebral aqueduct first seen, specifically?
Caudal midbrain
Spatially, where are the colliculi located?
Dorsal midbrain
Specifically, where in the brainstem are the substantia nigra and red nucleus seen?
Rostral midbrain
Which CN exits the brainstem at the interpeduncular fossa?
CN III
What are the main functions of the reticular formation?
- Arousal and consciousness
- Modulates pain pw’s
- Autonomic reflex circuitry
- Participates in control of movement (sc and cerebellum)
Where is the locus ceruleus (LC) located, specifically?
What NT is associated w/it?
- Rostral pons (posterior, touching PAG)
- Noradrenaline/NE
(has extensive projections in CNS; may adjust background levels of sensitivity?)
Where is the ventral tegmental area (VTA) located?
What NT is associated w/it?
- Midbrain
- Dopamine (w/SN)
What happens w/lesion to VTA?
What happens w/lesion to SN?
What is their relative spatial arrangement?
- Some form of mental disability
- Parkinson’s disease
- 2x SN’s laterally around the median VTA
Where is the Raphe located?
What NT is associated w/it?
- Most of the brainstem
- Serotonin (5-HT)
(Like those of the LC these neurons project all over and may adjust levels of attention or arousal)
What is the NT associated w/the rostral brainstem and basal forebrain?
What are the 2 key nuclei of the basal forebrain?
- Acetylcholine (ACh)
- Basal nucleus of Meynart and septal nuclei
The meynert nucleus projects to _____________________________.
Widespread areas of the cerebrum
Septal nuclei (medial olfactory area) project to the __________________.
Hippocampus
Destruction of the basal nucleus of Meynart and septal nuclei of the basal forebrain may lead to _____________.
Alzheimer’s disease
*Raphe works in a vineyard picking grapes.—So:
Also, uncle ______ has trouble moving his ________.
- SE Raphe’s Sustantial Dopey blue NE’s
- Uncle Meynart has trouble moving his cholinergics.
A stroke at PICA could cause what major syndrome?
What would it effect?
- Wallenberg syndrome (lateral medullary syndrome)
- Balance, taste, pain, speech, + produces a Horner’s syndrome.
- Loss of pain and temp in lower body below lesion on contralateral side + loss of pain and temp on ipsilateral side of head
If the inferior colliculus of the midbrain is the golfball on cross-section, what is the ball’s tee?
Lateral lemniscus
