Quiz
Visual System I
This quiz has question types that open in the usual player.
Questions in this quiz (43)
1Perception:
-conscious [blank_start]awareness[blank_end] and [blank_start]interpretation[blank_end] of sensation
-related to the [blank_start]particular sensory pathway[blank_end] in the [blank_start]nervous system[blank_end] that processes information from a [blank_start]receptor[blank_end]
-influenced by [blank_start]top down processes[blank_end]: cognition, attention, experience- Aawareness
- Binterpretation
- Cparticular sensory pathway
- Dnervous system
- Ereceptor
- Ftop down processes
2sensation [blank_start]does not equal[blank_end] perception
- Adoes not equal
3Light can be thought of in two different ways:
- [blank_start]particles of energy[blank_end] ([blank_start]photons[blank_end])
- [blank_start]waves[blank_end]- Aparticles of energy
- Bphotons
- Cwaves
4Visible light (for humans) is waves of electromagnetic energy between [blank_start]380-760 nm[blank_end]
- A380-760 nm
5Wavelength: [blank_start]color[blank_end]
Intensity: [blank_start]brightness[blank_end]- Acolor
- Bbrightness
6Light is changes by objects it encounters in its path: [blank_start]reflected[blank_end], [blank_start]refracted[blank_end] (bent), [blank_start]diffracted[blank_end], and [blank_start]absorbed[blank_end]
- Areflected
- Brefracted
- Cdiffracted
- Dabsorbed
7Refraction is [blank_start]wavelength[blank_end] dependent: for a given lens, [blank_start]short wavelengths[blank_end] (blue) are bent more than [blank_start]long[blank_end] (red) wavelengths
- Awavelength
- Bshort wavelengths
- Clong
8There is [blank_start]one-to-one correspondence[blank_end] between a point in space and a place on the receptor surface ([blank_start]retina[blank_end]) ([blank_start]an explicit map of space[blank_end])
- Aone-to-one correspondence
- Bretina
- Can explicit map of space
9Accessory structures ([blank_start]cornea[blank_end], [blank_start]lens[blank_end]) : [blank_start]shape[blank_end] the input to the receptor
- Acornea
- Blens
- Cshape
10[blank_start]Cornea[blank_end]: primary refractive element
- ACornea
11[blank_start]Iris[blank_end]: donut-shaped band of [blank_start]contractile[blank_end] tissue that gives the eye its color and regulates the amount of [blank_start]light[blank_end] entering eye via the size of the pupil
- AIris
- Bcontractile
- Clight
12[blank_start]lens[blank_end]: secondary refractive element (for near-vision: "accommodation")
- Alens
13[blank_start]Retina[blank_end]: epithelial tissue upon which image is projected, containing [blank_start]photoreceptors[blank_end] and associated [blank_start]neuronal circuitry[blank_end]
- ARetina
- Bphotoreceptors
- Cneuronal circuitry
14[blank_start]Extra-ocular muscles[blank_end] (horizontal, vertical, and oblique pairs) control eye movements:
- voluntary: [blank_start]saccadic and smooth pursuit[blank_end]
- reflexive: [blank_start]image stabilization[blank_end] ie head movements- AExtra-ocular muscles
- Bsaccadic and smooth pursuit
- Cimage stabilization
15[blank_start]Lens[blank_end]: focuses light on the retina
- ALens
16[blank_start]ciliary muscles[blank_end] alter the shape of the lens as needed
- Aciliary muscles
17[blank_start]Accommodation[blank_end]: the process of adjusting the lens
- AAccommodation
18The lens adjusts so that [blank_start]longer wavelengths of light[blank_end] (red and green) are in focus on the [blank_start]retina[blank_end]
- Alonger wavelengths of light
- Bretina
19The retina converts [blank_start]light[blank_end] to [blank_start]neural signals[blank_end]
- Alight
- Bneural signals
205 Layers of the retina from front to back
- [blank_start]retinal ganglion cells[blank_end]
-[blank_start]amacrine cells[blank_end]
-[blank_start]bipolar cells[blank_end]
- [blank_start]horizontal cells[blank_end]
- [blank_start]photoreceptors[blank_end]- Aretinal ganglion cells
- Bamacrine cells
- Cbipolar cells
- Dhorizontal cells
- Ephotoreceptors
21Inside-out:
Light passes through [blank_start]many cell layers[blank_end] before reaching its receptors. The [blank_start]pigmented epithelium[blank_end] absorbs any light that passes through the retina, and also provides [blank_start]metabolic support.[blank_end]- Amany cell layers
- Bpigmented epithelium
- Cmetabolic support.
22The retina exhibits two special regions:
- the [blank_start]fovea[blank_end]
- [blank_start]optic disk[blank_end]- Afovea
- Boptic disk
23Fovea: region of the [blank_start]macula[blank_end] (thicker area with an absence of blood vessels) where the layers of the retina above the photoreceptors are [blank_start]displaced laterally[blank_end] so that light can [blank_start]impinge more directly[blank_end] on the photoreceptors
- Amacula
- Bdisplaced laterally
- Cimpinge more directly
24optic disk: "[blank_start]blind spot[blank_end]", exit point for [blank_start]optic nerve[blank_end] ([blank_start]axons of retinal ganglion cells[blank_end])
- Ablind spot
- Boptic nerve
- Caxons of retinal ganglion cells
25Fovea:
- [blank_start]high acuity area[blank_end] at the [blank_start]center of the retina[blank_end]
- processes visual information from [blank_start]central 1 degree[blank_end] of visual space- Ahigh acuity area
- Bcenter of the retina
- Ccentral 1 degree
26Highest density of [blank_start]receptors[blank_end], [blank_start]bipolar[blank_end], and [blank_start]ganglion cells[blank_end] in retina; however, [blank_start]bipolar and ganglion cell bodies[blank_end] are displaced, creating a pt that [blank_start]minimizes light scattering[blank_end] between the lens and the photoreceptors
- Areceptors
- Bbipolar
- Cganglion cells
- Dbipolar and ganglion cell bodies
- Eminimizes light scattering
27Optic disk: region of retina with no [blank_start]receptors[blank_end] where [blank_start]retinal ganglion cell axons[blank_end] exit the eye (optic nerve)
The visual system "fills in" the blind spot based on information from [blank_start]the other eye[blank_end] or [blank_start]surrounding detail[blank_end] (called [blank_start]completion[blank_end])- Areceptors
- Bretinal ganglion cell axons
- Cthe other eye
- Dsurrounding detail
- Ecompletion
28Two main types of photosensitive cells, [blank_start]rods[blank_end] and [blank_start]cones[blank_end], which differ in a number of anatomical and physiological ways. Anatomical differences include [blank_start]size, shape, number, and location[blank_end] on the retina.
- Arods
- Bcones
- Csize, shape, number, and location
29There are no [blank_start]rods[blank_end] in the fovea, only [blank_start]cones[blank_end]. [blank_start]Rods[blank_end] predominate outside of the fovea.
- Arods
- Bcones
- CRods
30[blank_start]Duplex theory of vision[blank_end]: rods and cones mediate different kinds of vision
- ADuplex theory of vision
31Rods ([blank_start]scotopic[blank_end] vision):
- [blank_start]high[blank_end] sensitivity (nighttime)
- [blank_start]low[blank_end] acuity (high convergence)
- [blank_start]no color[blank_end]- Ascotopic
- Bhigh
- Clow
- Dno color
32Cones ([blank_start]photopic[blank_end] vision):
- [blank_start]low[blank_end] sensitivity (daytime)
- [blank_start]high[blank_end] acuity (low convergence)
- [blank_start]color[blank_end]- Aphotopic
- Blow
- Chigh
- Dcolor
33Scotopic vs Photopic vision
- [blank_start]rods[blank_end] do not supply information concerning color, but they are most sensitive to shorter wavelengths of light
- [blank_start]cones[blank_end] are sensitive to longer wavelengths- Arods
- Bcones
34Three types of cones in the retina:
- [blank_start]red[blank_end]: most sensitive to long wavelengths (L)
- [blank_start]green[blank_end]: sensitive to the mid-range of wavelengths (M)
- [blank_start]blue[blank_end]: sensitive to short wavelengths (S)- Ared
- Bgreen
- Cblue
35In the human retina, most cones are [blank_start]red and green[blank_end] type (but the relative ratio can vary widely) and few are [blank_start]blue[blank_end] because the lens focus longer wavelengths of light onto the retina
- Ared and green
- Bblue
36[blank_start]Component[blank_end] (trichromatic) theory: color is encoded (initially) by the ratio of activity in the three kinds of receptors
- AComponent
37Photoreceptors are modified epithelial cells or so called short receptors:
- [blank_start]no axonal process[blank_end]
- [blank_start]synaptic-mimetic[blank_end]: functionally and morphologically similar to presynaptic nerve endings; [blank_start]transduction currents[blank_end] modulate release of neurotransmitter- Ano axonal process
- Bsynaptic-mimetic
- Ctransduction currents
38Outer segment: [blank_start]transduction[blank_end]
- [blank_start]modified cilium, densely folded[blank_end]
- [blank_start]photopigments[blank_end] respond to light and [blank_start]alter membrane currents[blank_end]
- replaced [blank_start]daily[blank_end]- Atransduction
- Bmodified cilium, densely folded
- Cphotopigments
- Dalter membrane currents
- Edaily
39Inner segment: [blank_start]transmission[blank_end]
- synapses with [blank_start]bipolar and horizontal cells[blank_end]
- transduction currents modulate release of [blank_start]glutamate[blank_end]- Atransmission
- Bbipolar and horizontal cells
- Cglutamate
40The outer segments of photoreceptors contain [blank_start]disk-bound photoreceptor proteins[blank_end], specifically [blank_start]rhodopsin[blank_end] (rods) and [blank_start]photopsins[blank_end] (cones). Photopigments consist of two components: [blank_start]retinal[blank_end], a small molecule derived from vitamin A that changes shape as it absorbs light; and [blank_start]opsin[blank_end], a protein which determines the spectrum of photons captured.
- Adisk-bound photoreceptor proteins
- Brhodopsin
- Cphotopsins
- Dretinal
- Eopsin
41Photoreceptors are [blank_start]depolarized[blank_end] in the dark, and [blank_start]hyperpolarize[blank_end] in response to light
- Adepolarized
- Bhyperpolarize
42In the dark (ie unstimulated):
- [blank_start]cGMP-gated Na+ channels[blank_end] are open, leading to inward ([blank_start]depolarizing[blank_end]) NA+ current (so called dark current)
- Vrest ~ [blank_start]-40mV[blank_end]
- [blank_start]glutamate[blank_end] released- AcGMP-gated Na+ channels
- Bdepolarizing
- C-40mV
- Dglutamate
43In response to light (stimulated):
- [blank_start]retinal[blank_end] changes shape
- [blank_start]opsin[blank_end] dissociates and activates a unique G-protein ([blank_start]transducin[blank_end])
- [blank_start]transducin[blank_end] activates the enzyme phosphodiesterase (PDE) which breaks down cGMP
- [blank_start]cGMP-Na+ channels[blank_end] close
- membrane [blank_start]hyperpolarizes[blank_end] (~ -70mV)
- [blank_start]reduced[blank_end] release of glutamate- Aretinal
- Bopsin
- Ctransducin
- Dtransducin
- EcGMP-Na+ channels
- Fhyperpolarizes
- Greduced
Information
- Description
- Quiz on Visual System I, created by Hannah Miller on 10/11/2019.
- Author
- Hannah Miller
- Language
- English
- Views
- 4
- Rating
- No ratings yet Rate this quiz