The Visual System Flashcards
What major cerebral vessel is lateral to the chiasm?
A. Anterior cerebral artery.
B. Middle cerebral artery.
C. Internal carotid.
D. Posterior communicating artery.
Internal carotid
The internal carotid artery is immediately lateral to the chiasm. Ballooning of the vessel wall, (an aneurysm), can cause pressure on the chiasm and cause a partial, nasal hemianopsia.
Where do the axons of these cells go?
A. The optic disc.
B. The inner plexiform layer.
C. The outer plexiform layer.
D. All of the above.
E. None of the above.
The optic disc
Ganglion cells, between the arrows, send their axons to the thalamus and pretectal region. They leave the retina in the optic nerve. Axons from the retina pass through the optic disc or blind spot.
This area is necessary for the
A. Accommodation reflex.
B. Pupillary light reflex.
C. Blinking.
D. Night vision.
The pupillary light reflex depends on the integrity of the pretectal region. This nucleus contains the interneurons for the reflex.
Most cell bodies of neurons in this nucleus send their axons to
A. Upper and lower calcarine cortex.
B. Lower half of calcarine cortex.
C. Upper half of calcarine cortex.
Upper and lower calcarine cortex
There is a massive projection from the lateral geniculate to area 17. So many myelinated axons end in layer 4 of the cortex that a white line can be seen in gross specimens.
This area of cortex is supplied by branches of the
A. Posterior cerebral artery.
B. Middle cerebral artery.
C. Anterior cerebral artery.
D. Anterior choroidal artery.
Posterior cerebral artery
The posterior cerebral artery comes off the basilar artery. Its branches include the calcarine artery which supplies the visual cortex (circled).
This region is characterized by
A. Absence of bipolar cells.
B. Lack of blood vessels.
C. Absence of ganglion cells.
D. Absence of rods.
E. All of the above.
All of the above
The central retinal artery is a branch of the
A. Ophthalmic artery.
B. Anterior inferior cerebellar artery.
C. Ciliary arteries.
D. Anterior choroidal artery.
Ophthalmic artery
The ophthalmic artery is the first branch of the internal carotid artery and goes along the optic nerve. It gives off a branch, the central retinal artery, that penetrates the optic nerve head to spread out over the inner surface of the retina.
Retinal detachment occurs because this region (arrow)
A. Is the site of fusion of the optic cup and optic vesicle.
B. Is poorly vascularized.
C. The pigment epithelium is part of the choroid and adheres to it.
Is the site of fusion of the optic cup and optic vesicle.
As the optic vesicle secondarily invaginates forming the optic cup the neurorecepter and pigment epithelial layers become apposed, but a potential space remains between the two. Retinal detachment occurs along this weak junction.
What portion of the visual field is represented in the left lateral geniculate?
A. The superior half of the visual field of both eyes.
B. The inferior half of the visual field of both eyes.
C. The right half of the visual field of one eye.
D. The right half of the visual field of both eyes.
E. The left half of the visual field of both eyes
The right half of the visual field of both eyes
This artery is a branch of the
A. Basilar artery.
B. Middle cerebral artery.
C. Anterior cerebral artery.
D. Anterior choroidal artery.
Basilar artery.
The posterior cerebral artery is usually a branch of the basilar artery. It supplies the occipital lobe. Occlusion of this vessel or the middle cerebral artery or the choroidal artery produce a similar visual field defect
What part of the ventricular system is closest to the optic radiations?
A. Aqueduct.
B. Posterior horn of the lateral ventricle.
C. Fourth ventricle.
D. Third ventricle.
E. Frontal horn.
Posterior horn of the lateral ventricle
This line of of myelinated axons in layer IV of visual cortex represents the axons of cells in the
A. Superior colliculus.
B. Lateral geniculate.
C. Retina.
D. Medial geniculate.
E. Oculomotor nucleus.
Lateral geniculate
95% of the retinal ganglion cells project to the lateral geniculate. In primates this is the dominant visual pathway. There are so many that they can be seen as a white line (Gennari) with the naked eye
The structure indicated in this horizontal section
A. Is located above the tectum.
B. Has its embryological origin in the diencephalon.
C. Is near the posterior border of the third ventricle.
D. When enlarged can cause compression of the cerebral aqueduct.
E. All of the above.
All of the above
A specific sensory nucleus of the thalamus can be defined as:
A. On the direct relay path between the receptors and the specific sensory cortex.
B. Projecting to primary sensory cortex.
C. Topographically organized.
D. A relay (synaptic) station important in processing sensory information.
E. All of the above.
All of the above
This is a horizontal section through the thalamus with the rostral end up. This is the way radiologists look at horizontal sections.
What fibers compose this tract?
A. Bipolar cell axons.
B. Ganglion cell axons.
C. Photoreceptor axons.
Ganglion cell axons
What is the difference between the optic nerve and tract?
A. One has oligodendrocytes and the other Schwann cells.
B. One has third order axons and one has second order axons.
C. One has only ipsilateral axons and the other has both ipsilateral and contralateral axons.
D. One is central nervous system tissue and the other is peripheral nervous system tissue.
One has only ipsilateral axons and the other has both ipsilateral and contralateral axons.
At he arrow points to:
A. The falx cerebri.
B. The falx cerebelli.
C. The tentorium.
D. The tentorial notch.
The tentorium
