Neuro Lab 8 Flashcards
What is the function of the superior rectus?
elevate the eye, causes the cornea to move superiorly
What is the innervation of the superior rectus?
CN 3
What is the function of the inferior rectus?
depresses eye and causes the cornea and pupil to move inferiorly
What is the innervation of the inferior rectus?
CN 3
What is the function of the medial rectus?
adduction of the eye
What is the innervation of the medial rectus?
CN 3
What is the function of the lateral rectus?
moves eye laterally
What is the innervation of the lateral rectus?
CN 6
What is the function of the superior oblique?
rotates the eye downward and away from the midline, and intort the eye
down and out
What is the innervation of the superior oblique?
CN 4
What is the function of the inferior oblique?
elevation, abduction, extorsion of the eye
up and in
What would occur if CN 3, 4, and 6 had lesions?
paralysis of the eye
Where is the optic nerve?
from eyeball to optic chiasm
Where is the optic tract?
after chiasm to nucleus
What is the function of the optic chiasm?
To relay and reorganize visual information from both eyes so the brain can process binocular (3D) visionallows the visual cortex to receive the same hemispheric visual field from both eyes
What is the function of the hypothalamus for vision?
controls sympathetic nervous system (SNS), which is responsible for pupil dilation, and parasympathetic nervous system (PNS), responsible for pupil constriction
What is the thalamus function for vision?
the lateral geniculate nucleus plays an essential role in normal visual processing
What is the function of the superior colliculus?
To coordinate rapid eye movements (saccades) and reflexive head and body orientation in response to visual, auditory, and somatosensory stimuli
Where is the superior colliculus?
What is the function of the pretectum?
controls pupillary light reflex
Where is the pretectum?
What is the function of the primary visual cortex?
receives visual information from retinas
What is the function of the calcarine fissure?
divides the upper and lower visual fields
Where is the calcarine fissure?
What is the function of the cuneus (upper bank)?
receives visual information from the lower visual eye field
Where is the cuneus?
What is the function of the lingual (lower bank)?
receives info from superior visual eye field
Where is the lingual (lower bank)?
What is the function of the parieto-occipital sulcus?
Provides a landmark for defining the location of the primary visual cortex. The lingual gyrus and the cuneus are the gyri immediately inferior and superior, respectively, to the calcarine sulcus.
What is the function of CN 3?
-movement of eyeball
-pupillary constriction and accommodation
Where is the nucleus of CN 3?
What is the function of CN 4?
Control the superior oblique muscle which rotates the eye downward and away from the midline, and intort the eye
Where is the nucleus for CN 4?
What is the function of CN 6?
controls the movement of the lateral rectus which moves the eye laterally
Where is the nucleus of CN 6?
What is the function of the frontal eye field of cortex?
control visual attention and eye movements. Electrical stimulation of this elicits saccadic eye movements
How does vision get received from the eye and travel to the cortex?
retina->optic nerve->optic chiasm->optic tract->lateral geniculate nucleus of thalamus->optic radiations->visual cortex
What would a lesion to the optic nerve cause?
blindness in the ipsilateral eye
What would a lesion to the optic tract cause?
homonymous hemianopsia
What would a lesion to the optic chiasm cause?
bitemporal hemianopsia
What would a lesion to the Meyer’s loop cause?
a contralateral homonymous superior quadrantanopia, sometimes termed a “pie-in-the-sky” defect
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What would a lesion to the visual cortex cause?
homonymous hemianopsia and macular sparring
Describe homonymous hemianopsia and how it will impact treatments.
A field loss deficit in the same halves of the visual field of each eye. You will need to make sure the patient turns their head and body to compensate for the loss of vision.
Describe neglect and how it will impact treatments.
An unawareness or unresponsiveness to objects, people, and other stimuli. Not all visual problem, they really have to turn their head and body a lot to see the affected side. Need to check affected side because they won’t attend to it. Tends to be more on the right side of the brain (left side of the body affected)
What is the function of CN 8?
hearing and balance
Where is the vestibular nucleus?
Where is the cochlear nucleus?
What is the function of the superior olive?
sound localization
Where is the superior olive?
pons: level of cranial nerve nuclei VI/VII
What is the function of the nucleus of lateral lemniscus?
carries information about sound from the cochlear nucleus to the contralateral inferior colliculus of the midbrain
Where is the nucleus of lateral lemniscus in the pons?
What is the function of the reticular formation for the auditory system?
connections account for activating effect of sound on CNS
Where is the reticular formation in a sagittal view of the brainstem?
What is the function of the inferior colliculus?
serve as the main brainstem relay nuclei for auditory function
-sound localization
What is the function of the medial geniculate body of the thalamus?
directs auditory attention
What is the function of the primary auditory cortex?
identifies pitch and loudness
Where is the primary auditory cortex?
(1)
What is the function of the secondary auditory cortex?
classifies sounds
Where is the secondary auditory cortex?
(2)
What is the function of Wernicke’s area?
language comprehension
What is the function of the internal acoustic meatus?
allows the passes of CN 7, CN 8, and labyrinthine artery
Describe how sound gets received from the ear and travels to the cortex.
cochlea –> hair cells –> cochlear nucleus
–>superior olive –>inferior colliculus
–> medial geniculate –> primary auditory cortex
What is the function of the anterior semicircular canal with ampullae?
detects forward and back head movement, like nodding
Where is the anterior semicircular canal?
What is the function of the posterior semicircular canal?
detects head tilt like tipping the head toward the shoulders
Where is the posterior semicircular canal?
What is the function of the horizontal semicircular canal?
detects horizontal movement of the head, such as swiveling the head side to side
Where is the horizontal semicircular canal?
What is the function of the utricle?
senses horizontal acceleration
Where is the utricle?
What is the function of the saccule?
sense vertical acceleration
Where is the saccule?
What is the function of the CN 8 in the vestibular system?
provides information about one’s body in space and time
What is the function of the medial longitudinal fasciculus in the vestibular system?
to integrate movement of the eyes and head movements to help keep balance
Where is the medial longitudinal fasciculus in the medulla?
What is the function of the vestibulocerebellum?
controls balance and eye movement
What is the function of the vestibulospinal tracts?
medial: Performs the synchronization of the movement of the eyes with the movement of the head so that eyes do not lag behind when the head moves to one side (neck muscles)
lateral: coordinate orientation of the head and body in space (extensors)
What is the function of the reticulospinal tract in the vestibular system?
controls posture to help orient head
What is the function of the vestibular cortex?
intimately interacts with the visual cortex to mediate self-motion perception and balance
What is the function of the parietoinsular vestibular cortex?
integrates sensory inputs from the vestibular, visual, and somatosensory systems, contributing to self-motion perception
What is the function of CN 11 in the vestibular system?
helps move the head to keep it oriented
Where is the nucleus of CN 11?
Describe how information gets received from the vestibular apparatus and travels to the cortex. Differentiate between peripheral and central systems.
The peripheral vestibular system goes all the way from the labyrinth to the connections with the peripheral nerve into the vestibular nuclei. The central vestibular system includes:
-The central vestibular nuclei in the brain stem
-The vestibular cerebellar connections
The vestibular ocular pathways
-The vestibular spinal pathways (postural control)
