Midbrain Flashcards
Divisions of midbrain
- Tectum: posterior to cerebral aqueduct
- Cerebral Peduncle: anterior to cerebral aqueduct
Define periaqueductal gray
Grey matter around the aqueduct
Periaqueductal gray is excited by ____ and excites the…
Encephalines & other opiates
Raphe nuclei of reticular formation
Raphe nuclei are ____ and send fibers to the spinal cord to ____
Serotoninergic
Suppress pain
Corpora quadrogemina
Tectum contains 2 superior & 2 inferior colliculi
Inferior colliculus is part of the ____
Auditory pathway
Inferior colliculus receives afferents from the ____
Lateral Lemniscus
Inferior colliculus sends efferents to the ____ via…
Medial geniculate body via inferior brachium
Superior colliculus receives afferents from the ____ via the ____
Optic tract via the superior brachium
Superior colliculus sends efferents to the edinger-Westphal nucleus for ____
Pupillary constriction
Cerebral peduncle is composed of…
Tegmentum of midbrain
Substantia nigra
Crus cerebri
What is the space between the 2 cerebral peduncles?
Interpeduncular fossa
What is the posterior wall of the Interpeduncular fossa?
Posterior perforated substance
At level of inferior colliculus, tegmentum of midbrain contains….
Decussation of superior cerebellar peduncles
At level of inferior colliculus, superior cerebellar fibers are…
Ascending from dentate nucleus, cross & head toward red nucleus
At Level of superior colliculus, tegmentum of midbrain contains the ____
Red nucleus
Subdivisions of Substantia nigra
Pars compacta
Pars reticulata
Pars compacta
Dopaminergic nucleus of basal ganglia involved in motion & addictive behaviour
Pars reticulata
GABAergic nucleus of basal ganglia involved in motion
Pathologic decrease of ____ in Substantia nigra is seen in ____
Dopamine
Parkinson’s disease
Antipsychotic meds used to treat symptoms of schizophrenia & bipolar are _____
Dopamine antagonists
Crus cerebri contains ____ in its medial 3/5
Corticospinal fibers
Medial & lateral fifths of crus cerebri hold ____ and ____ fibers on their way to the ____
Frontopontine & temporopontine fibers
Pontine nuclei
CN VI extraocular muscles
Lateral rectus
CN IV extraocular muscles
Superior oblique (down & in)
CN III extraocular muscles
Medial rectus
Inferior rectus (down & out)
Superior rectus (up & out)
Inferior oblique (up & in)
