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Flashcards in Midbrain Deck (18)
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1
Q

1.2 Components of Tectum

A

Corpora Quadrigemina w/ superior and inferior colliculi

2
Q

Superior vs. Inferior Colliculi

A

Vision and associate w/ lateral geniculate vs. hearing and associate w/ medial geniculate of thalamus

3
Q

3 Large Visible Contents of Tegmentum

A

Cerebral peduncle
Substantia nigra
Red nucleus

4
Q

Cerebral peduncle

A

Contains all corticospinal/pontine/bulbar descending motor fibers so contralateral. Also somatotropic

5
Q

Substantia nigra

A

Lots of melanin deposited so it looks black, but spreads DA

6
Q

14 Contents of Midbrain

A
III
Ventral tegmental area
Substantia nigra
Medial lemniscus
Superior colliculus and inferior
Periaqueductal gray
Trigeminothalamic tract
Cerebral aqueduct
Spinothalamic tract
Medial longitudinal fasiculus
Cerebral peduncle
Red nucleus
Trochlear nucleus
7
Q

Ventral Tegmental Area (VTA)

A

Medial aspect of substantia nigra under peduncle. Also contains lots of DA but instead of going to basal ganglia spreads all throughout brain like Raphe or ceruleus

8
Q

Periaqueductal Gray

A

Gray nuclei around cerebral aqueduct that do pain/autonomic and reticular area shit

9
Q

Branchium

A

Arm of colliculi that head to geniculate

10
Q

Pain Gating

A

Periaqueductal gray sends fibers to Raphe which send it to dorsal horn of spinal cord to modulate/override pain w/ descending signals

11
Q

2 Arteries Around III

A

Superior cerebellar and posterior cerebral a.s, so they can compress it

12
Q

3 Parasympathetic Effects of III

A

Pupillary constriction
Acommodation
Nucleus of Edinger-Westphal next to III nucleus, so lose one and you lose both

13
Q

Different Levels of the Two CNs

A

III at level of superior colliculus and IV and level of inferior

14
Q

Trochlear Nerve (IV) Path

A

Exits posterior and immediately crosses to innervate contralateral superior oblique muscle. So lesion nucleus its contralateral but nerve probably ipsi

15
Q

3 Signs of III Lesion

A

Pupil dilated bc lack of parasymp
Always looks towards lesion w/ that eye
Turn his head so always looking in direction of lesion to avoid diplopia

16
Q

Sign of IV Lesion

A

Head tilted opposite direction of lesion to compensate

17
Q

Parkinson’s

A

DA Loss in substantia nigra

18
Q

Weber’s Syndrome

A

Caused by stroke in branch of posterior cerebral or basilar a.
Ipsilateral loss of III and contralateral loss of motor control of skeletal muscles