Flashcards in Lecture 1: Eye pgs 1-12 Deck (83):
What is the transition from neural to non-neural retina called?
What is the site where axons exit the eye and enter the optic nerve?
What is the depressed area within the pigmented macula lutea?
What is the area of greatest visual acuity?
What takes of the aqueous humor and helps to maintain aqueous humor amount?
Canal of schlem
An outpocketing of the ________________ (optic vesicle and cup) gives rise to the retina and optic nerve.
The ____________, like the rest of the CNS, is myelinated by oligodendrocytes and can NOT regenerate
The lens ______ becomes the lens vesicle.
What is a Coloboma?
Incomplete closure of optic fissure. This is also known as "Cats eye" or "keyhole". This looks like the pupil has melted into the iris so there is a black line of the pupil, instead of just a circle in the middle of the eye.
What does the outer layer of the optic cup form?
Retinal pigment epithelium
What does the inner layer of the optic cup form?
What does the optic stalk form?
What is the optic fissure?
It is a fissure formed by the folding of the stalk upon itself. If this fissure doesn't close properly it will cause coloboma.
Where is the blind spot in the eye?
The conversion of light into neuronal excitation is called the basic __________________.
Basic retinal circuitry
What is the main circuit?
Photoreceptors -> bipolar cells -> ganglion cells
What is the order that the path of light goes through?
Optic nerve fiber layer -> Ganglion cell layer -> inner plexiform layer -> Inner nuclear layer (bipolar cells) -> outer plexiform layer -> outer nuclear layer (photoreceptors cell bodies) -> layer of rods and cones -> Retinal pigment epithelium -) choroid
What are the contents of the retinal pigment epithelium?
Simple cuboidal epithelium
What are the contents of the layer of rods and cones?
Light sensitive potions of the photoreceptors
What are the photoreceptors and what do they deal with?
Rods - black and white
Cones - color
What are the contents of the outer nuclear layer?
Nuclei of the photoreceptors
What are the contents of the outer plexiform layer?
Synapses between photoreceptors and bipolar cells
What are the contents of the inner nuclear layer?
Nuclei of bipolar cells (amacrine, horizontal and muller cells too)
What are muller cells and where do they extend to and from?
They are the glial cells of the eye and they extend from the basement membrane near vitreous chamber to the retinal pigment epithelium
What are the contents of the inner plexiform layer?
Synapses between bipolar and ganglion cells
What are the contents of the ganglion cell layer?
Cell bodies of ganglion cels
What are the contents of the optic nerve fiber layer?
Ganglion cell axons (axons=fibers) that go to optic disc and nerve
The ___________________ is a shallow depression within the pigmented macula lutea.
The fovea is filled with tightly packed _______ photoreceptors.
T/F - All other retinal cells other than cone photoreceptors are displaced laterally at fovea.
The site where ganglion cell axons converge and pierce a weakened area of the sclera, the lamina cribrosa, and enters into the optic nerve is called what?
The optic disk lacks ___________.
The optic nerve contains axons of the ______________________ cells.
Retinal ganglion cells
The fibers are unmyelinated in the retina, but become myelinated after they enter the _________.
What is it called when there is a swollen optic disc due to increased intracranial pressure (tumor,edema, or hemorrhage) transmitted along the subarachnoid space of the optic nerve?
What happens during a detached edema?
Trauma, vitreous shrinkage (with age), etc can result in separation of the retinal pigment epithelium from the neural retina (at the layer of the rods and cones). This detachment represents a reopening of the intraretinal space in the embryonic eye (between the outer and inner layers of the optic cup).
Retinal detachment separates the photoreceptors from their blood supply in the ____________.
The optic nerve fiber layer and ______________ cell layer are supplied by their own blood supply in the optic nerve fiber layer and inner plexiform layer
Ganglion cell layer
What portion of the membrane is known for pupillary constriction?
The superior colliculus is known for what?
Generation of the eye movements and orientation
What is the hypothalamus known for?
A ____________ map is a point to point map of the image falling on each retina.
The _________________ is defined as the area of the environment seen by each eye when the other eye is closed.
The visual fields can be divided into nasal and temporal halves, or superior and inferior halves.
The lens projects the visual fields upside down and ____________ onto the retina.
The temporal visual fields projects onto what?
The nasal visual fields projects onto what?
The inferior hemiretina is projected from which visual field?
The superior hemiretina is projected from which visual field?
All the ganglion cell axons from the retina combine to make the ____________.
The optic nerve is myelinated by ________________.
The optic chiasm is a crossing of ________ retinal fibers to contralateral optic tract.
nasal retinal fibers
The fibers from the ipsilateral temporal retina and contralateral nasal retina make up the __________________.
Where does the optic tract terminate into?
Lateral geniculate nucleus of the thalamus
Where do the axons of the cell bodies that reside in the LGN terminate?
Axons from the LGN first travel in the ___________________, then split with half of the fibers traveling through the parietal lobe and the other half through the temporal lobe.
Where is the primary visual cortex located?
What are the other names for the primary visual cortex?
Striate cortex or Brodmann's area 17
The primary visual cortex surrounds the ___________ fissure on the medial side of the occipital lobe, including the lingual gyrus and cuneus.
Give the pathway for superior vision.
Superior visual field -> inferior retina -> LGN -> temporal lobe visual radiations (meyer's loop) -> lingual gyrus (occipital lobe - inferior to calcarine fissure)
Give the pathway for inferior vision.
Inferior visual field -> superior retina -> LGN -> parietal lobe visual radiations -> cuneus (occipital lobe - superior to calcarine fissure)
The _________ gyrus corresponds to superior or upper vision.
Lingual gyrus (inferior to calcarine fissure)
___________ corresponds to inferior or lower vision.
What is anopia or anopsia?
Lack or defect of vision
What is hemianopia?
Defect of vision of a half of the eye's visual field
What is quadrantanopia?
Defect in vision of a quarter of an eye's visual field
What is homonymous?
Defect in same portion of the visual fields of both eyes
Where is there a vision loss in nasal hemianopia of the left eye?
Visual loss is in the nasal visual field of the left eye
Where is there a vision loss in right homonymous hemianopia?
Visual loss in the right half of the visual fields of both eyes
Where is there a vision loss in left superior homonymous quadrantanopia?
Visual loss in the left superior quarter of the visual fields of both eyes.
Lesions in the eye, retina, or optic nerve can cause impaired vision in the visual field of __________.
Lesions in the optic chiasm, optic tract, or further along the pathway can cause impaired vision in the visual fields of _____________.
An optic nerve lesion of the right eye is called _______________,________.
monocular blindness, right eye
An _____________________ lesion will lead to loss of afferent limb of pupillary light reflex (direct response).
optic nerve lesion
What would be the lesion site that is common with pituitary adenomas?
Optic chiasm in the midline
What would be the term associated with a lesion at the optic chiasm at the midline?
If there is a lesion at the lateral margin of the optic chiasm what occurs? (damage to right side)
Nasal hemianopia, right eye
What can cause a lateral margin of the optic chiasm lesion?
Aneurysms or calcification of the internal carotid artery
What can cause left homonymous hemianopia? (damage to right side)
A lesion at the optic tract, LGN, all visual radiations, internal capsule, or all primary visual cortex on one side.
What can cause left superior homonymous quadrantanopia? (damage to right side)
Lesions of the visual radiation fibers in the white matter of temporal lobe (Meyer's loop) or lesions of the lingual gyrus of the primary visual cortex.
When you have a lesion to the visual radiation fibers in the white matter of the parietal lobe or lesions of cuneusin the primary visual cortex can cause what defect? (damage to right side)
Left inferior homonymous quadranopia
Trauma or tumor to the primary visual cortex will result in what? (damage to right side)
Left homonymous hemianopia
Trauma to the primary visual cortex or occlusion of the posterior cerebral artery will lead to what? (damage to right side)
Left homonymous hemianopia with macular sparing