Visual cess
Introduction :
• Visual
process
in the series
of actions that take place during
perception
visual .
o
light spectrum in converted into Electrical Potentials by cells
chemical
og Retina through process
.
basis
. Thus visual sensation in
explained on the
of image
formation and neural ,
chemical & Electrical Phenomena .
Focal
°
length of cornea =
24mm ; lens -
44mm
Power
Refractory power
= 42 D
Refractory = 2313
. Retina has visual
Receptors / light sensitive / Photoreceptors .
°
Visual Receptors are Rods & cones .
°
There are about 6 Million Cones & 12 Million Rods .
structure
of Red cell :
• Rod cells are cylindrical structures with a
length of about
40 to
Gop and diameter of about
2T .
• Four structures :
(a) Outer
segment
( bi Inner
segment
c)
Cell
body
eds terminal
synaptic
outer
segment :
Rod
o
like appearance [ long slender ] &
• Outer
segment in
formed by modified cilia
and contains a
pile y freely floating
flat membranous
disks .
, • There are about tooo disks in each rod , and contain the
photosensitive pigment ,
the
Rhodopsin .
.
Newly formed disks are at lower
portion where
Rhodopsin is
synthesized .
New disks later the outer
push outer old and
•
ones ones are
phagocytosis ed by Pigment Epithelium layer cells .
• Rate y formation 7 New disks =3 -
4 / hour .
Inner
segment :
• Connected
segment by
to outer means
of modified cilium .
•
Inner
segment contains many types y Organelles with
large number
mitochondria
of
.
Cell Body :
In outer nuclear slender
layer enlarged portion of fibre
°
,
the a
forms cell
body / Rod granule that contains Nucleus .
Synaptic terminal :
•
Thick fibre arising from the cell body
to outer and
passes plexiform layer ends
and
in small
enlarged synaptic terminal
or
body .
•
Synaptic terminal of Rods synapses with
dendrites cells horizontal cells
og bipolar and .
•
Neurotransmitter =
Glutamate .
Structure 7 Cone
fell :
• Cone cells in the visual
receptor with
length og 35
µ to 40 te , diameter -
- 5
µ .
Introduction :
• Visual
process
in the series
of actions that take place during
perception
visual .
o
light spectrum in converted into Electrical Potentials by cells
chemical
og Retina through process
.
basis
. Thus visual sensation in
explained on the
of image
formation and neural ,
chemical & Electrical Phenomena .
Focal
°
length of cornea =
24mm ; lens -
44mm
Power
Refractory power
= 42 D
Refractory = 2313
. Retina has visual
Receptors / light sensitive / Photoreceptors .
°
Visual Receptors are Rods & cones .
°
There are about 6 Million Cones & 12 Million Rods .
structure
of Red cell :
• Rod cells are cylindrical structures with a
length of about
40 to
Gop and diameter of about
2T .
• Four structures :
(a) Outer
segment
( bi Inner
segment
c)
Cell
body
eds terminal
synaptic
outer
segment :
Rod
o
like appearance [ long slender ] &
• Outer
segment in
formed by modified cilia
and contains a
pile y freely floating
flat membranous
disks .
, • There are about tooo disks in each rod , and contain the
photosensitive pigment ,
the
Rhodopsin .
.
Newly formed disks are at lower
portion where
Rhodopsin is
synthesized .
New disks later the outer
push outer old and
•
ones ones are
phagocytosis ed by Pigment Epithelium layer cells .
• Rate y formation 7 New disks =3 -
4 / hour .
Inner
segment :
• Connected
segment by
to outer means
of modified cilium .
•
Inner
segment contains many types y Organelles with
large number
mitochondria
of
.
Cell Body :
In outer nuclear slender
layer enlarged portion of fibre
°
,
the a
forms cell
body / Rod granule that contains Nucleus .
Synaptic terminal :
•
Thick fibre arising from the cell body
to outer and
passes plexiform layer ends
and
in small
enlarged synaptic terminal
or
body .
•
Synaptic terminal of Rods synapses with
dendrites cells horizontal cells
og bipolar and .
•
Neurotransmitter =
Glutamate .
Structure 7 Cone
fell :
• Cone cells in the visual
receptor with
length og 35
µ to 40 te , diameter -
- 5
µ .
