Animal Sensory Systems P.3 Flashcards
1
Q
Planarians have … eyes that are a bean shaped layer of … innervated by …
A
cup (ocelli) , photosensitive pigment cells, five photoreceptive neurons
2
Q
Bivalves have … in the frills of their … Some even have …
A
eye spots, mantles, compound eyes
3
Q
… have the most advanced camera eyes with or without lens and cornea
A
cephalopods
4
Q
Some clams and arthropods have … eyes
A
compound
5
Q
Spiders have camera eyes that lack a …
A
lense
6
Q
Humans have…
A
camera eyes
7
Q
Channel rodopsins
A
Found in flagellated unicellular protists
8
Q
Protists benefited from having their … which could light activate their flagellum to stroke faster
A
poster eyespot
9
Q
More multicellular animals have photoreceptor cell specialization mainly…
A
sensitive rods and color discerning cones
10
Q
Rods
A
Sensitive to dimmer light conditions than are cones, cones are color specific
11
Q
Vertebrates have ciliary type photoreceptors that have modified cilia in the outer segment to form
A
disks
12
Q
The disks in the photoreceptors of the vertebrae eye contain … otherwise known as … that molecularly change when struck by a …
A
photopigments (contain retinal), chromatophores, photon
13
Q
rhabdomeric
A
another type of photoreceptor cell found in other animals
14
Q
retinal
A
isomerizes from an 11-cis to a trans-conformation when it absorbs the energy from a photon. Made from a vitamin A precursor and obtained in the diet.
15
Q
How does retinal go back to its original form? (cis)
A
Requires an isomerase enzyme and chemical energy from ATP
16
Q
Trans retinal activates the … protein and also detaches it, which prevents … from activating again
A
opsin, GPCR
17
Q
Bleaching
A
Detachment of trans retinal from opsin. Refractory period until a cis retinal reunites with the opsin.
18
Q
Reverse isomerization (regeneration)
A
takes a small amount of time which can lead to optical illusion of the aftermath affect.
19
Q
Cones are densely concentrated in the … of retina
A
fovea
20
Q
True or False: frogs dont have cones
A
True
21
Q
Neighboring rods and cones are connected through … which is called …, and increases
A
electrical synapses, cell-cell coupling, light sensitivity
22
Q
Many interneurons of the … of the retina are also connected by electrical synapses
A
nuclear layers
23
Q
Insects and nonmammalian vertebrates have photo receptors in their …
A
pineal gland (epiphysis) which respond to light and see the biological clock
24
Q
In mammals, the pineal gland receives signals indirectly via the … stimulated by the …
A
thalamus, optic nerves
25
decrease in photons hitting the retina relays to the pineal gland, stimulating it to secrete
melatonin
26
Phototransduction
Conversion of light energy to electrical impulses
27
Rhodopsin
Merges with retinal when a photon hits it
28
Opsins
A class of GPCRs. A 7 membrane surface receptor that activates the cytosolic G-protein it associates with when retinal shifts
29
The conversion of retinal from cis- to trans- activates this ..., causing the G protein to disengage and continue the signal cascade.
GPCR
30
Rhabdomeric photoreceptor cells (rPRC)
cells that look like a comb (microvilli). Handle of comb is axon.
31
In invertebrate photocytes (rPRC), photons strike the retinal in the GPCR activating an ... which depolarizes the cell's membrane potential
excitatory G protein (Gq)
32
In invertebrate photocytes (rPRC), after cell membrane is depolarized the Gq leaves the GPCR to activate ... which hydrolyzes ...
phospholipase C (amplifier enzyme increases sensitivity) , PIP2, IP3, diacyl glycerol
33
In invertebrate photocytes (rPRC) DAG activates ... which open up... eventually ...
cation channels, to let sodium and calcium into the cell, depolarizing it
34
IP3
Stimulates the release of stored calcium in the cell
35
Glutamate (amino acid) and acetylcholine
Two neurotransmitters secreted after exposure to light. Transduced into action potentials that go to the ganglion/ brain for interpretation
36
In invertebrate photocytes (rPRC) ... binds to ... to turn the signal off
arrestin, rhodopsin
37
In vertebrate photoreceptors the G protein ... in an inhibitory protein which ... the cells membrane potential
transducin, hyperbolizes
38
In vertebrate photoreceptors ... begins to convert cyclic GMP to GMP in an amplified manner which inactivates sodium channels causing...
phosphodiesterase (PDE), hyperpolization
39
In vertebrate retinas, exposure to light makes the rod or cone cell secrete less ... which inhibits ...
neurotransmitters, action potentials
40
In vertebrates, when light hits the retina, graded signals called ... to the inner nuclear layer of ... and the outer nuclear layer of ...
receptor potentials, bipolar neurons, ganglion cells
41
In vertebrates, several rods form ... with the ... of a single bipolar neuron
synaptic connections, dendrites
42
In vertebrates, cones are each individually connected to one
bipolar cell
43
No vertebrate has ... receptors
rhabdomeric
44
... and ... cells modulate the synapses of the PRCs and can even reverse polarity of incoming signal
horizontal, amacrine
45
Besides most vertebrates, camera eyes independently evolved in...
cephalopods, gastropods, jellies, annelids, at least one copepod curstacean
46
Arachnids also have camera eyes but theyre ... and use a ... shaped .... to focus the light onto the photosensors
non-adjustable, dome-shaped, cornea
47
Ocelli
Little insect eyes on the top of their head that serve as a light meter by which they can entrain their circadian clock
48
Compound eyes
clusters of individual light-sensitive tubes that each have a lens. come in various subcategories, depending on the placement or position of the photoreceptors & the refraction caused by having a smooth versus a rough surface. Insect, crustaceans, some mollusks and annelids
49
Apposition compound eyes
found in most land arthropods.
50
Superposition compound eyes
have a gap between lenses and retina. allows more photons to scatter over a great photoreceptor surface. suited for dark environments
51
Refracting (rough surface) cornea
works well in dim light. nocturnal insects, shrimp
52
Reflecting (smooth surface) cornea
Decapod shrimps, lobsters
53
Parabolic
Mayflies
54
Superposition compound eyes
have a gap between lenses and retina. allows more photons to scatter over a great photoreceptor surface. suited for dark environments, moths
55
The insect compound eye consists of hundreds of
ommatidia. Each with a convex eye, cornea, crystalline cone, and ring of long, retinular cells surrounding a tube in which light passes from the conical lens
56
Retinular cells
microvilli extends from these cells, called rhabdomere. They increase the surface area for the opsin proteins that detect light that descends down the tube
57
Rhabdomere
scaffolds of actin support the developing microvilli. the microvilli face the light. The microvilli face the light aligning along the optical axis.
58
Compound eyes also have ..., which means they can focus on an object very near to it.
macro focus
59
Limpets
A mollusk. Have a flat epithelium of photosensitive cells attached to nerve endings
60
Abalone
A mollusk. Have eye cups which improve photoreception by sharpening the objects image. The light reflecting off of the object can be perceived from different angles when the light-sensitive cells are arranged in a curve. Analogous to planarian eye
61
Nautilus
A mollusk. Has a deeper cup containing more cells that is filled with a thick fluid. It sharpens the image even more
62
Gastropod (marine snails)
A mollusk. have a cornea and a simple lens
63
Squid and octopus (mollusks) have a thick ... and controllable ...
cornea, lens
64
Hagfish
eyes lack a lens. the retinal cup lies behind a translucent patch of skin. they may regress even further if they continue to dwell in the Midnight Zone
65
Lamprey
Have a simple lense behind transparent skin with a more developed retina. They lack a true cornea and ciliary muscles meaning they cannot focus the image by deforming the lens
66
Do difference in the retina between cephalopods and vertebrates is that
vertebrates have a reversed retina posing many flaws
67
Cephalopod eye and retina.
Have a single layer of photoreceptors + supporting cells. Lens shape is more circular for focusing light in water. Has a different refractive index than air. Signals are sent to a fat bulge called the optic ganglion.
68
Vertebrate eye and retina
vertebrates have completely backwards wiring with photoreceptors away from the light and buried under two layers of neurons and supporting glial cells and blood vessels. The blood vessels need to punch through the retina to reach the brain creating the optic disk (blind spot)
69
Interneurons of the retina include, ..., ...., and ...
bipolar, horizontal, and amacrine cells
70
Bipolar cells
pre process light information to retinal ganglia
71
Horizontal cells
integrate. lateral inhibit signal helps find center of strongest light stimulus
72
Amacrine cells
inhibit signals recieved by the ganglion cells
73
Eyeshine from the ... is an iridescent membrane behind the ... in many vertebrates in a lining called the ...
tapetum lucidum, retina pigment epithelium (RPE), choroid
74
The tapetum lucidum is a ... and is not present in any primates except for the ...
retroreflector, lemur
75
How does a camera eye focus on an image?
1. incoming light is refracted by the lens ( made of crystalline proteins) bent to a focal point on the retina
2. When the object can be squarely viewed, it hits the macula region which contains sharpest resolution
3. In macula a hollow called the fovea (containing cone receptors)
76
The lense is held in place by
suspensory ligaments
77
Seeing distant objects
relaxing the ciliary muscles dilates lense, flattening it. This reduces refraction.
78
Seeing closer objects
Light needs to be refracted more. Contracting the ciliary body shortens circular muscles which removes the tug of suspensory ligaments allowing the lens to return to default convex shape.
79
Focal accommodation is automated as a reflex controlled by
the optic and oculomotor cranial nerves
80
Myopia
Nearsightedness is increasing in prevalence.
81
Hemifield
the visual field of one eye
82
binocular zone
the overlap in visual field
83
Stereopsis
when information is processed by each eye from a slightly different perspective.
84
The retina of each eye can be divided into a ... and ... side
nasal (inside) , temporal (outside)
85
Optic chiasm
The X that forms from nerve axons bundled in the optic nerve
86
From the X, optic tracts continue to the ... and then back to the brains ...
lateral geniculate nucleus (LGN), occipital lobe
87
Contralateral nasal retinas
They innervate the LGN of opposite hemisphere
88
Ipsilateral temporal retinas
Only project in the same hemisphere
89
The dual processing of the object by multiple regions of the visual cortex enhances
depth perception
90
Visual feedback
improved motor function due to being able to see your limbs
91
Nasal retinas are larger in
prey
92
Predators (cheetah) have forward-facing eyes that increase
Binocular vision and depth perception
93
Prey (gazelle) have laterally-placed eyes that have
Wider range of vision
94
Gain of stereopsis leads to decrease in
lateral vision
95
Trichromatic
3 major cones express one of the following opsins. Some reptiles fish and birds are this but a lot of them are tetrachromatic etc. . Old World Primates including humans are this.
96
Dichromatic
Most other mammals are this due to the loss of a functional copy of the LWS opsin (Red)
97
Monochromatic
Nocturnal animals. Lost MWS and LWS (red and green) (paralogs on the X chromosome for gene duplication)
98
Relaxed selection
When a selective pressure is taken away
99
Simiiformes
Old World, and New World Monkeys
100
Cercopithecoidea
Old World Monkeys
101
New World primates are largely
dichromatic
102
The mantled howler monkey was dichromatic but a ... allowed it to eventually evolve into trichromacy because of the disadvantage of not being able to see red
tandem gene duplication
103
The entire exoskeleton of .... fluoresce blue/green when absorbing UV wavelengths
scorpians
104
Whole-body UV Photon Collector Hypothesis
UV excitation to blue-green light can be seen and felt by the scorpian in their eyes.
105
Chelicerata
a subphylum of arthropods that also includes horseshoe crabs and spiders
106
plesiomorphic trait
phenotypic trait that arose in the ancestral species in a clade
107
Coumarin
a poison that scorpions can eat that they can digest and break it down into UV-fluorescent compounds deposited in the exoskeleton
108
Which animal has the most advanced eyes?
mantis shrimp (stomatopods) (hexnocular vision)
109
Crabs, lobsters, and shrimp have...
compound eyes split into 3 parts. Top is dorsal, middle is midband (color is perceived) and last is ventral each of which have a black median stripe
110
In animals that can see polarized light, the light enters ... perpendicular to the ... of the ....
ommatidia, microvillie, rhabdomere
111
Depending on the orientation of the rhabdomeric photoreceptor, it could be excited and
depolarize action potentials
112
an offset UV receptor filters the incoming light so that only a ... or ... wave can pass through to the photoreceptors
horizontal oriented, vertically oriented
113
Monoplat, dipolat, tripolat
organism equipped with a one two or three-dimensional polarization system
