Chapter 42: Vision Flashcards
According to the description in chapter two, the retina is an outgrowth of the _____.
- Forebrain (diencephalon)
Vision requires the activity of both the _____ and the _____.
- Eyes
- Brain
The optic nerve is made up of the _____ of the ganglion cells of the retina.
- Axons
A small number of the axons in the optic nerve reach the _____ and the _____ nucleus via the brachium of the superior colliculus.
- Superior colliculus
- Pretectal
The overwhelming majority of the axons in the optic nerve synapse in the _____ of the _____.
- Lateral geniculate nucleus
- Thalamus
As noted in chapter 34, each lateral geniculate nucleus receives information about the _____ visual field from ganglion cells in both retinas.
- Contralateral
Ganglion cells in the right halves of both retinas send information about the _____ visual field to the _____ lateral geniculate nucleus.
- Contralateral
- Ipsilateral
Axons from the _____ half of the left retina must cross over in the optic chiasma to reach the _____.
- Right (medial)
- Right lateral geniculate nucleus
Since the _____ nucleus of the hypothalamus is just above it, the optic chiasma must be just _____ to the pituitary stalk which descends below the arcuate nucleus.
- Suprachiasmatic
- Anterior (rostral)
Each of the optic tracts that run from the optic chiasma to the lateral geniculate nuclei is made up of 50% axons from the _____ side of the ipsilateral retina and 50% axons from the _____ side of the contralateral retina.
- Ipsilateral
- Ipsilateral
Because the lens system of the eye reverses and _____ the image, information about the right visual field reaches the _____ lateral geniculate nucleus through the _____ optic nerve and the _____ optic tract.
- Inverts
- Left
- Right
- Left
Information about the upper visual field reaches the _____ half of each lateral geniculate nucleus in the ipsilateral _____.
- Lower
- Optic tract
The lower half of each lateral geniculate nucleus projects visual information from the _____ half of the visual field to the lower half of the ipsilateral posterior occipital cortex, Brodmann area 17.
- Upper
The upper half of each lateral geniculate nucleus projects visual information from the _____ half of the visual field to the upper half of the ipsilateral posterior occipital cortex, Brodmann area 17.
- Lower
Brodmann area _____ is the primary visual cortex.
- 17
The primary visual cortex, Brodmann area _____, is the posterior third of the _____ lobe.
- 17
- Occipital
The primary visual cortex is often called the calcarine cortex because its medial surface is split into upper and lower halves by the _____ sulcus.
- Calcarine
The calcarine artery, which is a branch of the posterior cerebral artery, usually runs in the opening of the _____ sulcus.
- Calcarine
The primary visual cortex is completely dependent on the _____ for its blood supply unless there is an anastomosis with an occipital branch of the middle cerebral artery on the lateral surface of the occipital lobe.
- Calcarine sulcus
The half of each primary visual cortex above the _____ receives visual information about the _____ half of the _____ visual field.
- Calcarine sulcus
- Lower
- Contralateral
The upper half of each lateral geniculate nucleus projects to the _____ half of the _____ calcarine cortex through the superior geniculocalcarine tract.
- Upper
- Ipsilateral
The half of each primary visual cortex below the _____ receives visual information about the _____ half of the _____ visual field.
- Calacarine sulcus
- Upper
- Contralateral
The lower half of each lateral geniculate nucleus projects to the _____ half of the _____ calcarine cortex through the inferior geniculocalcarine tract.
- Lower
- Ipsilateral
When the temporal lobe grew down from the _____ lobe during the first trimester it took a loop of the _____ geniculocalcarine tract with it.
- Occipital
- Ipsilateral
The loop of the inferior geniculocalcarine tract inside the posterior part of the _____ lobe is called Meyer’s loop.
- Temporal
_____ makes the inferior geniculocalcarine tract longer than the superior geniculocalcarine tract.
- Meyer’s Loop
A lesion in one part of the visual system causes a dark region in the perceived visual fields. The dark region is called a scotoma from the Greek word for _____, “scotos.”
- Dark
One can find the lesion by analyzing the pattern of a _____.
- Scotoma
Loss of both right and left visual fields of one eye is the easiest _____ to analyze.
- Scotoma
Complete scotoma of one eye is due to loss of the _____ nerve or loss of the eye itself.
- Optic
The optic nerve can be attacked by multiple sclerosis because it is part of the _____ system.
- Central nervous
The ophthalmic artery runs alongside the optic nerve and supplies it. An aneurysm of the ophthalmic artery will press on the optic nerve and _____ its function.
- Impair (degrade)
Destruction of the retina will cause the same scotoma as destruction of the _____.
- Optic nerve
The retina is completely dependent on the central artery of the retina, which is a branch of the ophthalmic artery. Thus, occlusion of the ophthalamic artery or the central artery of the retina destroys the _____ and leaves that eye _____.
- Retina
- Blind
A thrombus in the ophthalmic artery, unless promptly dissolved, will _____ the _____ nerve.
- Destroy (infarct)
- Optic nerve
For there to be a chance of restoring vision after occlusion of the central artery of the retina, the _____ must be removed within 4 hours.
- Clot (obstruction)
In a case of central artery occlusion the window of opportunity for restoring sight is only _____.
- 4 hours
Monocular scotoma may be due to destruction or loss of function of the _____ or the _____.
- Retina
- Optic nerve
Loss of function may be due to an _____.
- Aneurysm
Destruction may be due to _____ of the _____ artery or the _____ of the _____.
- Occlusion
- Ophthalmic
- Central artery
- Retina
Destruction of one optic tract causes loss of the contralateral visual field of both eyes. Hemianopia is the loss of _____ of one’s range of vision. Hemianopia is homonymous if and only if both eyes lose the right visual field or both eyes lose the left visual field.
- Half
Only the axons from the left sides of the retinas are cut. Thus only the _____ visual field is lost.
- Right (contralateral)
Each lateral geniculate nucleus relays information about the contralateral visual field to the calcarine cortex. Damage to the left lateral geniculate nucleus would cause _____.
- Right homonymous hemianopia
Damage to the right lateral geniculate nucleus would cause _____.
- Left homonymous hemianopia
Each lateral geniculate nucleus gets its blood supply from the _____ artery which is a branch of the _____.
- Thalamogeniculate
- Posterior cerebral artery
Occlusion of the left thalamogeniculate artery would cause _____.
- Right homonymous hemianopia
One possible cause of a left homonymous hemianopia would be a thrombus in the _____ artery.
- Right thalamogeniculate
Obviously, a left to right cut through the optic chiasma would cut _____ of the axon from _____ retinas. This cut would cause total _____.
- All
- Both
- Blindness
The right visual field of the right eye is often called the temporal field. The left visual field of the right eye is often called the nasal field. Thus the left visual field of the left eye is the _____ field, and the right visual field of the left eye is the _____ field.
- Temporal
- Nasal
If the cut through the optic chiasma is perfectly
centered, only theaxons from the medial halves of
the retinas are cut. Thus, only the _____ visual fields would be lost. The result of an antero-posterior cut through the optic chiasma can also be
called bitemporal _____.
- Temporal
- Hemianopia
If the cut through the optic chiasma is perfectly
centered, only the axons from the medial halves of
the retinas are cut. Thus, only the _____ visual fields would be lost. The result of an antero-posterior cut through the optic chiasma can also be called bitemporal _____.
- Temporal
- Hemianopia
Since the pituitary stalk is just behind the optic chiasma, a _____ tumor can press on the optic chiasma and cause _____ that can be cured by surgical removal of the _____.
- Pituitary
- Bitemporal hemianopia
- Pituitary gland
Visual information is relayed to area _____ of the ipsilateral cerebral cortex by the _____ via the geniculocalcarine tracts.
- 17
- Lateral geniculate nucleus
The left lateral geniculate nucleus sends an image of the lower half of the _____ visual field to the upper half of area _____ of the cerebral cortex via the ipsilateral superior geniculocalcarine tract.
- Ipsilateral
- 17
The right lateral geniculate nucleus sends an image of the upper half of the _____ visual field to the lower half of area _____ of the cerebral cortex via the _____ inferior geniculocalcarine tract.
- Left
- 17
- Ipsilateral
The superior geniculocalcarine tract runs caudad through the parietal and occipital lobes and ends in superior lip of the calcarine sulcus, which is the _____ half of Brodmann’s area _____.
- Upper
- 17
The superior lip of the calcarine sulcus receives an image of the _____ quadrant of the visual fields via the _____ tract.
- Contralateral inferior
- Ipsilateral superior geniculocalcarine
Interruption of the left superior geniculocalcarine tract would cause loss of the _____ half of the_____ visual field or _____ quadrantanopia.
- Lower
- Right (contralateral)
- Right superior
Destruction of the upper lip of the right calcarine sulcus would cause _____.
- Left inferior quadrantanopia
The superior geniculocalcarine tract and both lips of the calcarine sulcus receive their _____ supply from the posterior cerebral artery.
- Blood
Occlusion of a posterior cerebral artery causes scotoma of the _____ visual field.
- Contralateral
The inferior geniculocalcarine tract loops _____ through the temporal lobe carrying an image of the _____ half of the _____ visual field.
- Downward (inferad)
- Superior
- Contralateral
The loop of the inferior geniculocalcarine tract in the posterior half of the _____ lobe is called _____.
- Temporal
- Meyer’s Loop
Damage to an inferior geniculocalcarine tract or to the upper lip of the calcarine sulcus causes _____.
- Contralateral superior quadrantanopia
Due to its position in the _____ lobe, Meyer’s loop gets its blood supply from the _____ artery.
- Temporal
- Middle cerebral
Occlusion of the middle cerebral artery causes _____.
- Contralateral superior quadrantanopia
Because both lips of the calcarine sulcus are served by the ipsilateral _____ infarction of the calcarine cortex usually results in _____.
- Calcarine artery
- Contralateral homonymous hemianopia
The posterior end of the calcarine cortex, where the image on the macula of the retina is received, often has a dual blood supply from the both then_____nbranch of the _____ and the middle cerebral artery.
- Calcarine
- Posterior cerebral artery
If the posterior end of the calcarine cortex has a dual blood supply, occlusion of the calcarine branch of the posterior cerebral artery will cause _____ with macular sparing, but occlusion of the posterior cerebral artery itself will cause _____ with sparing of only the upper part of the contralateral macular _____.
- Contralateral homonymous hemianopia
- Hemianopia
- Field
Because the calcarine cortex is just below the occipital pole, a blow to the back of the head can cause total _____ or _____ hemianopia.
- Blindness
- Homonymous
A blow to the back of the head or a fall on the back of the head may damage only the posterior end of the calcarine cortex where the image on the _____ of the _____ is seen. This results in a _____ or _____ scotoma.
- Macula
- Retina
- Macular
- Bimacular
The primary visual cortex in Brodmann area _____ edits the visual information to enhance the sharpness of the image and sends it to the _____ visual cortex in Brodmann area 18 which surrounds it.
- 17
- Secondary
The secondary visual cortex in Brodmann area _____ surrounds the _____ visual cortex in Brodmann area _____.
- 18
- Primary
- 17
The secondary visual cortex in Brodmann area _____ sends only the pattern of motion to the tertiary visual cortex in Brodmann area 37 which relays it to the parietal association cortex, Brodmann area 7.
- 18
The parietal association cortex in Brodmann area _____ projects to the _____ of the midbrain to assist in unconscious tracking movements of the eyes.
- 7
- Superior colliculus
The secondary visual cortex in _____ sends the pattern of dots, blocks, and lines it acquired from _____ to the tertiary visual cortex in Brodmann area 19 which surrounds it.
- Brodmann area 18
- Brodmann area 17
Brodmann area 19 assembles the pattern of dots and lines acquired from _____ into a recognizable shape based, in part, on experience.
- Brodmann area 18
Because Brodmann area 19 uses _____ to assist in the construction of shapes from the pattern of dots and lines received from Brodmann are _____, it may mistake a novel shape for a familiar one.
- Experience
- 18
Because Brodmann area 19 relies heavily on _____, a newborn or a person blind from birth who gains sight as an adult when a congenital cataract is removed or a defective cornea is replaced spends the first 2 weeks learning to see.
- Experience
Oliver Sacks’ famous case of the man who mistook his wife for a hat had suffered a stroke in Brodmann area _____ and saw both simply as two vertical lines about 6 inches apart.
- 19
Brodmann area _____ projects the shape it has constructed to Brodmann are 20 in the inferior temporal gyrus for identification.
- 19
Brodmann area 20 occupies most of the _____.
- Inferior temporal gyrus
If the object resembles familiar objects Brodmann area 20 _____ it; if the object is completely novel Brodmann area 20 notes its unfamiliarity.
- Identifies
A person with damage to area _____ and an intact area _____ can draw an object, but he can neither name it nor use it.
- 20
- 19
Brodmann area _____ project its identification of the object to area 21 in the middle temporal gyrus for naming.
- 20
Brodamann area 21 in the _____ names things, but only with common (generic) names.
- Middle temporal gyrus
Brodmann area 20 also projects to both areas 36, the anterior occipitotemporal gyri on the inferior surface of the _____ lobe.
- Temporal
The left area 36 in the left _____ recognizes letters and ideograms.
- Occipitotemporal gyrus
A stroke in the left area _____ causes alexia, the inability to read (regardless of language).
- 38
Area 36 in the anterior right _____ recognizes faces.
- Occipitotemporal (fusiform) gyrus
A stroke in the right area _____ causes prosopagnosia, the inability to recognize faces.
(Greek: prosop=face, a=without, gnosis=knowledge)
- 36
Brodmann area 36 recognizes the uniqueness of things. The left Brodmann 36 recognizes _____, and the right Brodmann area 36 recognizes _____.
- Letters
- Faces
Brodmann area 7, the _____ receives information about changes in spatial relationships from Brodmann area 37 which received the information from Brodmann area _____.
- Parietal association cortex
Brodmann area 7 also receives information about spatial relationships from the _____ of the thalamus which received the information from a lateral geniculate body.
- Pulvinar
Damage to one Brodmann area _____ or to one side of the _____ of the thalamus leaves the patient with little or no consciousness of the contralateral visual field.
- 7
- Pulvinar
A patient with damage to one Brodmann area _____ or to one side of the _____ of the thalamus is said to have contralateral neglect syndrome.
- 7
- Pulvinar
A patient with left _____ syndrome due to a stroke in the _____ parietal cortex or _____ side of the pulvinar will draw a clock with all 12 numerals on the right and a daisy with petals only on the right side.
- Contralateral neglect
- Right
- Right
A patient with a stroke in the _____ parietal cortex or _____ side of the pulvinar does not know that he has a left hand.
- Right
- Right
If a patient with left _____ is shown his left hand, he may call it a specimen from the anatomy lab. If he knows of the Humphrey Bogart movie he will probably call it the left hand of God.
- Contralateral neglect syndrome
A patient with a stroke in the left (dominant) parietal association cortex may know that his _____ hand exists and be able to grasp with it, but he will be unable to make skilled movements with it.
- Right
A patient with a stroke in the left (dominant) parietal association cortex will probably know that there are things on his _____, but he will manipulate them poorly and only with his left hand.
- Right
Brodmann area 7 is conscious of the _____ field and the _____ side of the body.
- Contralateral visual
- Contralateral
Brodmann area 7 receives projections from Brodmann area _____ and the _____.
- 18 (or 37)
- Pulvinar
Brodmann area _____ knows what things are, but only Brodmann area _____, knows what they are called.
- 20
- 21
The left Brodmann area 36 in the occipitotemporal gyrus recognizes _____, and the right area 36 recognizes _____.
- Letters
- Faces
Each superior calcarine cortex receives information about the _____ half of the _____ visual field from the _____ lateral geniculate nucleus.
- Inferior
- Contralateral
- Ipsilateral
Each lateral geniculate nucleus receives impulses from the _____ halves of both retinas containing information about the _____ visual field.
- Ipsilateral
- Contralateral
The superior geniculocalcarine tract is entirely within territory of the _____ artery, but most of the inferior geniculocalcarine tract is mostly in the territory of the _____ artery.
- Posterior cerebral
- Middle cerebral
