Physio - Optical properties of Eye & Vision Flashcards
Which layer of the retina contains the Cell bodies of rods & cones?
Outer Nuclear Layer (ONL)
Which layer of the retina contains the Nuclei of horizontal, bipolar and amacrine cells ?
Inner Nuclear Layer
What structures are found in the Outer Plexiform layer?
Rod and cone axons
Horizontal cell dendrites
Bipolar dendrites
Which layer of the retina axons of bipolars (and amacrines), dendrites of ganglion cells ?
Inner Plexiform Layer
Which structures are found in the Layer of the Ganglion cells?
Nuclei of the ganglion cells and displaced amacrine cells .
Fill in the blanks.” ___________________ connect receptor cells to other receptor cells in the outer plexiform layer. “
Horizontal cells
Fill in the blanks. “ ________________ connect ganglion cells to one another in the inner plexiform layer.”
Amacrine cells
Which region of the highest visual activity of the retina?
Fovea
True or False? The Fovea is the centre of the retina .
TRUE!!
Fill in the blanks. “ _______________ are black /white receptors.”
Rods
What is the functions of the Rods?
To detect motion, responsible for peripheral vision, low-light vision.
True or False? In the retina , Light BLOCKS cGMP binding.
TRUE!!
Fill in the blanks. “ _____________ need bright light for activation (photopic vision) while ___________ are inactive during the day ( Scotopic vision) .
CONES - need Bright light ( Photopic vision )
RODS- are inactive during the day ( Scotopic vision )
Fill in the blanks. “ Cones are found in the ___________ and concentrated in the __________.”
Cones are found in the Macula Lutea, concentrated in the Fovea Centralis.
True or False? There are more Cones than Rods in the eyes.
FALSE!! There are more Rods in the eyes than cones.
120 milli in eye ( rods)
6 milli in eye (cones)
’ Rods rules!!’
True or False? Photopic vision ( Cones) distinguishes shapes and colors while Scotopic vision ( Rods) distinguishes shapes but not colors.
TRUE!!
Which vision is used at night when the light intensity is LOW?
Scotopic vision
Which bipolar cells are Glutamate INHIBITORY to ?
On- Centre( H) bipolar cells
Which bipolar cells are Glutamate is EXCITATORY to?
Off- Centre ( D) bipolar cells
Where are midget bipolar cells concentrated?
In the Fovea
Fill in the blanks. “ Rods bipolar cells listen to _________.”
15-45 rods
Fill in the blanks. “ Cone bipolar cells listen to ________.”
5-20 adjacent cones
Which cells play a role in “ centre/sound detection”?
Horizontal cells
Fill in the blanks. “ ___________ release GABA continuously if NOT activated but when they become activated by receptors they cease GABA release preventing the cone and rod receptors from signaling light detection.”
Horizontal cells
What is the best stimulus for Horizontal cells?
Illumination of a large area of retina.
Fill in the blanks. “ Rod bipolar cells do not connect directly to ganglion cells, but rather indirectly via __________.”
Amacrine ( non-polar) cells
Which cells are the output of the retina and are known as the ‘on’& ‘off’ centre receptive cells?
Ganglion cells
True or False? M cells are Not colour sensitive and handle low contrast.
TRUE!!
What is the Visual pigment of Rods?
Rhodopsin (opsin + 11-cis retinal)
Fill in the blanks. “ 11-cis retinal + opsin regenerate __________.”
Rhodopsin
Which colour is Rhodopsin most sensitive to?
Blue-Green
Fill in the blanks. “ Ganglion cells of the retina project their axons towards the ___________ of the eye.”
Posterior pole
What layer numbers are Magnocellular layers?
Layers 1&2
What layer numbers are Parvocellular layers?
3,4,5& 6
Small visual field deficits are called?
Scotomas
Large visual field deficits are called?
Anopsias.
The amount of light entering the eye is controlled by the?
Iris
Iris muscles are controlled by ANS. Fill in the blanks ‘ PNS innervate ___________ while SNS innervate _____________ .’
PNS innervate circular muscle
SNS innervate radial muscle
Fill in the blanks. “ ______________ causes circular muscles of the eye to contract.”
Parasympathetic stimulation
Fill in the blanks. “ ________________ causes radial muscles to contract .”
Sympathetic stimulation
What is the name given to the pathology when a patient has loss of central vision?
Central Scotoma
