Lecture 4 - Brainstem Flashcards
Which cranial nerves have their nuclei in the midbrain?
CN III (Oculomotor)
CN IV (Trochlear)
CN V (trigeminal)
Which cranial nerves have their nuclei in the pons?
CN V (trigeminal)
CN VI (abducens)
CN VII (facial)
CN VIII (vestibulocochlear)
Which cranial nerves have their nuclei in the medulla oblongata?
CN IX (glossopharangeal)
CN X (vagus)
CN XII (hypoglossal)
CN V (trigeminal)
What does the brainstem connect?
Cerebrum/Cerebelum to Spinal Cord
What are the three compartments of the brainstem?
- midbrain
- pons
- medulla
What is the division of the brainstem ONLY in the midbrain?
Tectum
What is the division of the midbrain with the ascending tracts called?
Tegmentum
What is the division of the midbrain with the descending tracts called?
Basilar
What is a conduit?
ascending/descending pathways
Where are 9/12 of the cranial nerves nuclei?
the brainstem!!
What do the cranial nerves from the brainstem do? (generally)
head and body functions
What are integrated functions of the brainstem?
consciousness, alert, arousal, vital centers, etc.
What are the ascending tracts in the junction between the midbrain and diencephalon?
- spinal, trigeminal, medial leminisci
- parietal-temporal-occipital pontine fibers
- corticospinal fibres
- corticonuclear/corticobulbar fibers
- frontopontine fibers
What does the cerebral peduncle contain?
descending tracts
What is a peduncle?
column that supports the cerebrum
What kind of functions do the corticonuclear and corticobulbar fibres do?
somatic motor
What is the ventral posteiror nucleus?
fibers gather to form synapsis with their neurons in the thalamus nuclei here.
VPM - for the face and
VPL - for everything below the neck
What is the riMLF in the junction between the midbrain and diencephalon?
an integrated function - the vertical gaze center
- controls eyes going up and down
- “rostral interstitial nucleus of medial longitudinal fasciculus”
What are the two parts of the substantia nigra in the junction between the midbrain and diencephalon?
- pars compacta and pars reticularis
What does the pars compacta part of the substantia nigra do?
UMN except eyes, controls somatic motor functions
What does the pars reticularis part of the substantia nigra do?
EYES, Unique
What is the UMN control system?
the red nucleus
What is a colliculus?
“Small mountain”, two bumps
How many colliculi are there?
4 - 2 superior and 2 inferior
Where are the colliculi?
posterior of the midbrain
We start to have ___ ___________ in the colliculus level of the rostral midbrain
CN attachments
What are the ascending tracts in the superior colliculus level?
- spinotectal tract
- spinal leminiscus / anterolateral system
- trigeminal lemniscus
- medial lemniscus
What is the spinotectal tract for?
sensory feedback for motor control
What is the spinal lemniscus / anterolateral system for?
perception, temperature, fine touch, vibration, pain, etc
What is the trigeminal lemniscus for?
perception, temperature, fine touch, vibration, pain, etc in the FACE
What is the medial leminiscus in?
dorsal column ascending up
What are the integrated functions in the rostral midbrain at the superior colliculus level?
- aqueduct and PAG
- red nucleus
- substantia nigra pars compacts
- substantia nigra pars reticularis
- ventral tegmnetal nucleus
What inetgrated function controls award and aversion, and is where addiction happens?
ventral tegmental nucleus
What is the PAG integrated function of the rostral midbrain?
Peri-Aqueductal Gray Matter
Peri - around
aqueductal - cerebral aqueduct
What are the nuclei of the oculomotor nerve? (CNIII)
- dinger-westphal nucleus and oculomotor nucleus
What is the difference between the nuclei of CNIII?
- dinger-westphal nucleus - parasympathetic for visceral motor control
- oculomotor nucleus - somatic motor control
What are the colliculus tracts for reflexive neck motions?
Decussation of the tectospinal tracts
What is decussation?
CROSSOVER
What level is the decussation of the tectospinal tracts at?
superior colliculus level