What makes up the cerebral peduncle?
the tegmentum and the crus cerebri
rostrally the midbrain merges with the ___
the boundary between the midbrain and the diencephalon is marked by the ___
the posterior comiisure forms a bridge between
the prectatal areas on each side of the brain stem
What can damage the posterior commisure?
Symptoms of a tumor of the pineal gland
1. can't make upward eye movements
2. puts pressure on prectal area --> block the pupillary light reflex --> fixed dilated pupils
3. hydrocephalus if obstructing the cerebral aqeudct
what is the vertical gaze center in the prectal area?
the intersitial nucleus in the pretectum
what can cause deficits with upward gaze?
1. damage to the nculeus of cajal (vertical gaze center)
2. damage to the posterior commisure (because axons of Nucleus of Cajal pass through here)
What is INC?
What sx would you get with a X here?
Interstial gaze center (Nucleus of Cajal)
can't do an upward gaze
the lateral lemniscus travels to the ____
Where do the fibers of the superior cerebellar peduncle cross?
at the level of the midbrain at the decussation of the superior cerebellar peduncle
a lesion of the dorsal tegmentum in the midbrain may imapir
propathic (ALS) and epicritic (MLS) from the opposite side of the body and face
where in the thalamus do axons from the superior cerebellar peduncle travel to?
VA and VL
where does the rubrospinal tract originate?
the red nucleus
Where does the red nucleus project to inth e thalamus?
VA and VL
Nuclei in the midbrain
1. the trochlear nucleus
2. occulomotor nucleus
the periaqeudctal gray surrounds the ____
Function of the periaqueductal gray?
1. intiating some sterotyped emotional behaviors (rage)
2. controlling the perception of pain
why is the substantia nigra black?
because the dopamergic neurons produce melanin
Why do loss of dopamergic neurons in the substantia nigra cause parkinsons?
because there is a loss of input to the striatum
where do the dopamergic neurons in the reticular formation of the midbrain project to?
the cerebral cortex and to the limbic structures of the forebrain
What cholinergic neurons are important for regualting the sleep wake cycle?
the cholinergic neurons at the pons mibdrian junction
What damage in the midbrain can cause coma
X to the rostral region of the reticular formation
-(cholinergic neurons at the pons and midbrain)
what does the basal ncuelus of meynert do?
modulates cortical function
where is the basal nculeus of meynert located?
deep to the anterior eprforated substance
what is the basal nculeus of meynert implicated in?
in alzheimers disease
trochlear nerve innervates the ___ muscle
how to sx trochlear nerve palsy
if pt looked nasally..
1./ they couldn't look down from that position
2. would also have double vision here in this positon
____ innervates the levator palpebrae muscle
the Edinger-Westphal nucleus contains preganglionic parasympathetic neurons that project to the ______
EW to cicilary ganglion pathway is repsonsible for
1. pupillary constriction
2. thickening of the lens
accomdation with convergence of the pupils
what does damage to the edinger westphal nucleus look like?
1. eye is fixed and deviated outward
2. the downward lid droops
3. pupil is dialted
4. pupil is unresponsive to light be shown in the eye