Visual System

Question 1

Perception takes place in

Answer 1

Retina

Question 2

Retina

Answer 2

Inner most layer of the eye, covered by CT, in contact with vitreous humor

Question 3

How many layers of cells has the reina

Answer 3

3

Question 4

Cells within the layers of the reina

Answer 4

Photoreceptors
Bipolar cells
Ganglion cells

Question 5

Retinal layers

Answer 5

Pigment epithelium
Outer and inner segment layer (cons and rods)
Outer nuclear layer (nucleus of photoreceptors)
Outer plexiform layer (synapsis PR w/ next cell layer)
Inner nuclear layer (bipolar cells)
Inner plexiform layer (synapse bipolar with ganglion cells)
Ganglion cell layer
Nerve fiber layer (axons of the ganglion cell layer)

Question 6

Part where we don’t find photoreceptors

Answer 6

Optic nerve

Question 7

Vision is

Answer 7

A cognitive process performed by comparison

Question 8

Cons perceive

Answer 8

Color - allows to see shapes

Question 9

Rods perceive

Answer 9

Shades of light (intensity) - allows to see movements

Question 10

Fovea

Answer 10

Middle part of the macula

Area of the retina that defines what we see

Question 11

Retinal pigmented epithelium

Answer 11

Tightly bound pigmented cuboidal cells. Unstable

Suplies the retina with glucose and ions. Phagocitosis

Melanin processes elongate to protect from light

Question 12

Outer segment of the photoreceptors

Answer 12

Stacking membranous discs

Molecules of Rhodopsin (finite reactions to light). Coneopsins

10% phagocitized every morning (by retinal pigment epithelium)

Question 13

Retinal changes in photoreception

Answer 13

Retina changes its conformation when it interacts with photons

Question 14

Photoreceptors components

Answer 14

Cilium (microtubules)
Inner segment: mitochondrias
Nucleus
Synapse (feet): rods (spherule), cones (pedicles) and synaptic ribbons

Question 15

Macula

Answer 15

Central area of the posterior retina that starts lacking retinal layers (there’s only photoreceptors)

Question 16

Photostimulation

Answer 16

Photon-ops in reaction hyperpolarizes the photoreceptor

Question 17

In resting conditions, photoreceptors are

Answer 17

Depolarized
Constantly releasing glutamate

Question 18

Hyperpolarization causes

Answer 18

Reduction of glutamate liberation

Question 19

Depolarization vs hyperpolarization

Answer 19

Electrons moving towards the neutral point

Electrons moving away from neutral point

Question 20

Gradient potential

Answer 20

Hyperpolarizes photoreceptors

Question 21

Bipolar cells

Answer 21

(After hyperpolarization)

On: activated when glutamate is no longer in the synapse (light)

Off: deactivated in light conditions, activate in relax conditions when glutamate get to postsynaptic terminal

Question 22

Horizontal cells

Answer 22

Inhibits photoreceptors in a center-surround manner

Question 23

Receptive fields

Answer 23

Created by horizontal cells, which inhibit the peripheral part and activate the center

Question 24

Colors perceived by retina

Answer 24

Blue (S wavelength), green (M wavelength), red (L wavelength)

Question 25

Colour theory by which the retina works

Answer 25

Substractive synthesis

Question 26

Which receptive fields are compared in between?

Answer 26

Green and red

Question 27

Types of cells

Question 28

Parallel transmission and processing

Question 29

Types of ganglion cells

Answer 29

M/Y/alfa —> ON center, OFF center P/X/beta —> ON center W/K —> melanopsin

Question 30

W/K cells relevance

Question 31

Visual pathway

Answer 31

Each of the eye has a temporal field (to the nasal retina) and nasal field (to the temporal retina) The cortex controls same hemifields from both eyes (right hemifield form right and left eye, left hemifield from right and left eye) —> some of the fiber has to cross to the other side in the optic quiasm Optic tract: fibers from the same field Sinapsis: late geniculate body Projection: optic radiation

Question 32

Projections to the visual cortex

Answer 32

Visual hemifields are divided in superior and inferior quadrants. They are caught by the opposite retinal quadrant and reach different banks of the calcarine sulcus

Question 33

Optic radiation

Question 34

Visual cortex

Answer 34

Has the largest layer 4

Question 35

Visual areas are classificated in

Answer 35

Cytoarquitectonic Functional

Question 36

Discrepancy of the eye

Answer 36

3D, depth perception

Question 37

Depth perception

Answer 37

Only with 2 eyes

Question 38

V1

Answer 38

Blobs

Question 39

V2

Answer 39

Thick stripes magno Thin stripes parvo

Question 40

Cytochrome function

Answer 40

Oxidase blobs and stripes

Question 41

Complex cells respond to

Answer 41

A line moving

Answer 42

Color Dominance bands Direction of lines

Question 43

Parvo celular pathway

Answer 43

What I am seeing

Question 44

Magno celular pathway

Answer 44

Where are the things I am seeing

Question 45

Thick stripes

Answer 45

Motion

Question 46

Thin stripes

Answer 46

Colours

Question 47

Interstripes

Answer 47

Depth

Question 48

V1/V2