Brain and Behavior

The optic nerve is formed from the axons of the ____ and passes through the optic canal into the ______.

As the optic nerve is an extension of the brain, it is surrounded by the ___ and is bathed in ____.

The four destinations of the fibers of an optic nerve are:

The retina is divided into a _____ hemiretina, medial to the fovea, and a ____ hemiretina, lateral to the fovea. .

Each of the four hemiretinas is further divided into a ___ and ____quadrant. Each quadrant is supplied by a corresponding branch of the ______ artery

The right half of the visual field projects on the ___ hemiretina of the right eye and the _____ hemiretina of the left eye.

The inferior half (or quadrant) of the visual field projects onto the ____ half (or quadrant) of the retina.

Damage to the inferior half of the retina causes a loss in the ____ half of the visual field. Damage to the nasal half of the retina causes a loss in the temporal visual field.

The optic nerves come together to form the _____ just anterior to the pituitary gland.

The nasal retinal fibers (of each eye) cross the midline in the ___ to reach the _____ optic tract

The nasal fibers carry the ____ visual field of the respective eyes.

The temporal retinal fibers do not cross in the chiasm and maintain a ___ position in the optic nerve, the optic chiasm, and the optic tract. The temporal retinal fibers carry the ___ visual field of the respective eyes.

Retinal fibers carrying left visual field information (of both eyes) end up in the ___ optic tract.

A pituitary tumor compressing the fibers crossing in the chiasm will produce a lesion of the fibers from the ___ portions of each retina, resulting in a loss of information of the ____ visual fields of both eyes; thus, ______

The optic tracts pass around the cerebral peduncles to reach the ___.

One could say that retinal fibers carrying left visual field information end up in the ___optic tract.

A lesion of an optic tract often results from a vascular accident involving the ____.

A lesion of the central visual pathways beyond the optic chiasm ALWAYS involves the __ visual field and ALWAYS involves the __ visual field of both eyes.

Most of the fibers of an optic tract terminate in ___. Some fibers pass around the lateral geniculate nucleus, enter the brachium of the ___ and terminate on neurons in the ____ or the ___. Some post-chiasmatic fibers terminate in the____.

The lateral geniculate nucleus (7) is a six layered nucleus, laminated so that layers 1,4, and 6 receive ___ retinal fibers from the ___ eye and layers 2,3, and 5 receive ___ retinal fibers from the ___ eye.

Each layer of the lateral geniculate nucleus contains a full representation of the viewed object and each part of the image is registered in the adjacent part of each layer. The visual image now has a ____ representation.

The horizontal image in the LGN results from axons from the __ part of the retina terminating on neurons in the __ part of the lateral geniculate nucleus.

A lesion of the lateral geniculate nucleus often results from a vascular accident involving the ___ or ____.

The visual field loss resulting from a lesion of the lateral geniculate nucleus would be __ and ____. (comparable to a lesion of the optic tract)

The neurons of the lateral geniculate nucleus project their axons to the ____ in the ___.

The optic radiations (geniculocalcarine tract) initially travel rostrally through the posterior limb of the ___. The fibers then bend posteriorly behind the ____and are there called the ____ part of the internal capsule.

The optic radiations divide into two bundles after they pass beyond the _____ part of the internal capsule. One bundle, ____, carrying one half of the fibers from the lateral geniculate
nucleus, loops forward into the temporal lobe.

The Loop of Meyer carries fibers corresponding to fibers in the _____ retinal quadrants-- which corresponds to the _____ visual field quadrants.

Fibers in the optic tract and lateral geniculate nucleus carry __ of each visual field; and now, in the optic radiations, the half fields are further divided into __ quadrants.

The upper portion of the optic radiations carrying a
___ visual field quadrant, takes a more direct route around the ___ to get to the primary visual cortex.

A typical lesion of the optic radiations involves only the upper or lower fibers of the optic radiations and results in a loss of _____ of the visual field; _____ .

A lesion of the optic radiations typically results from a vascular accident involving the cortical branches of the ____. As the two bundles of the optic radiations proceed posteriorly around the lateral ventricle, the visual image is ___ and ____.

The two bundles of optic radiations come closer together in the ____part of the ____and form a very thick, broad, heavily myelinated bundle which passes to the ___.

At the location where the two bundles of optic radiations are closest together, a single lesion can affect all of the optic radiation fibers and produce a ___,____ ______.

The optic radiations terminate in a narrow band of cortex above and below the ______ in
the ______ .

The upside-down image is registered in the primary visual cortex so that (for a human figure) from head to waist is registered in the ___ and from waist to feet in the _____. The narrow primary visual cortex is ____.

______ of optic radiations as they penetrate deeper into the cortex gives the primary visual cortex a striped appearance and it is therefore also called the ____.

The visible stripe where the myelin drops off in the primary visual cortex (layer IVb) is called ___.

The primary visual cortex is organized into functional columns in which all cells in a straight line
perpendicular to the ____ have similar properties.

All cells in a column which respond particularly to one eye instead of the other are called ___ columns.

The areas of the occipital lobe around the primary visual cortex are ___ and are heavily interconnected with area 17.

Areas __ and___ are secondary and tertiary visual association areas. Information about the visual image is conducted from area __ to areas __ and __ for further integration (color, 3-D, etc.)

Information from the cone cells of the macula of the retina are found __ placed and ___ represented in all structures in the central visual pathways.

The ____ image is often not involved in incomplete lesions because of its central location. sparing.

Macular sparing even in large lesions because:

A lesion of the primary visual cortex often affects the upper bank (___) or lower bank (_____) of the primary visual cortex and would therefore only affect ___ of the primary visual cortex on a side. Thus, such a lesion, often resulting from a vascular accident involving the calcarine artery (a branch of the posterior cerebral artery) would result in a ____ , upper or lower, homonymous, ______ anopsia with______.

Fibers from each occipital lobe pass through the ___ of the corpus callosum to the opposite occipital cortex. This bilateral representation is thought to aid in producing _____.

Fibers from each occipital lobe pass to the __ and ___ lobes and are believed to be involved in the interpretation of movement or color and form, respectively.

All areas of the cerebral cortex are interconnected by _____. Thus, all lobes receive some input from the occipital lobe.

Deficits in the visual system are usually referred to as ___.

Loss of a part of a visual field is an ___.

Total loss of vision in the one eye is called ___

Loss of vision in the temporal halves of the visual field of both eyes is called ___.

Loss of vision in the opposite half of the visual field of both eyes is called ___.

Loss of vision in the upper quadrant of the visual field of both eyes on the opposite side is called ___.

Partial loss of vision in the lower quadrant of the visual field of both eyes on the opposite side is called ____.

Partial loss of vision in the upper quadrant of the visual field of both eyes on the opposite side is called___.

Lesions in area 1 marked would cause what type of visual defect?

Lesions in area 2 would cause what type of visual defect?

Lesions in area 3 would cause what type of visual defect?

Lesions in area 4 would cause what type of visual defect?

Lesions in area 5 would cause what type of visual defect?