Basal Ganglia Flashcards
What are the 5 components of the basal ganglia?
How are they grouped?
caudate nucleus, putamen, globus pallidus, substantia nigra, subthalamus
caudate nucleus and putamen are the striatum
putamen and globus pallidus are the lentiform nucleus
What is the input to the basal ganglia? Where do they go?
goes to the striatum. comes from cerebral cortex, thalamus, brain stem raphe nuclei, and the substantia nigra (reciprocal connections)
What are the connections around the globus pallidus?
projects to the primary motor and premotor cortex via nuclei VL and VA of the thalamus, respectively. Reciprocal connection with the subthalamus.
What muscle is controlled by CNIII?
SR, IR, MR, inferior oblique, levator palpebrae (also sphincter muscles- not voluntary)
What muscle is controlled by CNIV?
superior oblique
What muscle is controlled by CN VI?
lateral recturs
What muscles are controlled by CNXI?
sternocleidomastoid and trapezius
optic nerve lesion: what visual field defect?
ipsilateral monocular blindness
optic chiasm nerve lesion: what visual field defect?
bitemporal hemianopsia
optic tract lesion: what visual field defect?
contralateral homonymous hemianopsia (ie. if the right tract is lesioned, the left visual field is lost on both eyes). Very rare.
lateral geniculate lesion: what visual field defect?
contralateral homonymous hemianopsia (ie right lateral geniculate lesion means left visual field lost on both eyes). much more common than optic tract lesion.
Meyer’s loop lesion: what visual field defect?
lesion to the loop that goes through the temporal lobe.
contralateral superior quandrantanopsia (pie-in-the-sky)
parietal optic radiations lesion: what visual field defect?
contralateral inferior quadrantanopsia
occipital cortex lesion: what visual field defect?
contralateral homonymous hemianopsia. more common than optic tract lesion. (most common?)
