Term
| what makes up a specialized sensory receptor? how many types of stimuli can each detect? |
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Definition
very distinct population of cells with distinct features
can only detect 1 type of stimulus |
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Term
| what kind of photoreceptors are there? |
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Definition
| there is a huge variance - all the way from simple light detection to complex images |
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Term
| what are the parts of the photoreceptor in a planaria? |
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Definition
has a bent part called the eye cup
light strikes eye cup, hits and splits visual pigment, turns into an electrical impulse that produces the action potential |
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Term
| what is the most simple form of photoreception called? |
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Definition
photoataxis
the decision to go towards or away light
postitive photoataxis is towards, negative photoataxis is away |
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Term
| where are photoreceptors for actual vision found? |
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Definition
vertebrates, arthropoda, mollusca
NOT echinodermata |
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Term
| how did photoreceptors evolve? |
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Definition
| independently within each group |
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Term
| what animals have a compound eye? what exactly is it? |
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Definition
arthropods
many visual units creating the lens |
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Term
| what is the 4 step process for a compound eye? |
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Definition
1. lens bends the light
2. visual pigment in photoreceptor cell splits
3. sensory neuron sends message
4. processed in circumesophageal ganglion |
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Term
| what is the compound eye mostly used for? |
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Definition
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Term
| what are the lens components in a compound eye shaped like? |
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Definition
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Term
| how are the cephalopod eye and the vertebrate eye similar? |
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Definition
| both hace retina, cornea and lens |
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Term
| why do cephalopods (squid, octopi) have such advanced eyes? |
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Definition
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Term
| what part of the vertebrate/cephalopod eye is used for focusing? what do these look like? why? |
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Definition
lens and cornea
both very transparent and curved
bend light to pinpoint on the retina |
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Term
| what does the retina connect to? |
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Definition
| connects to neurons to go to the visual center of the brain through the optic nerve |
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Term
| what are the 2 visual structures in the eye and what does each do? |
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Definition
rods - detects colorless vision in dim light
cones - detect color (red, blue, green) |
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Term
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Definition
| light hits and splits the Rhodopsin pigment molecules into opsin and retinal, causing the action potential |
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Term
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Definition
3 populations of cells each absorb light of the corresponding color wavelength
pigment molecules differ in each type of cone, called photopsins |
|
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Term
| what are the pigment molecules in the eye? |
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Definition
in the rods Rhodopsin splits into opsin and retinal
in the cones photopsins split |
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Term
| what is the top layer of cells in the eye and what do they do? |
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Definition
Muller cells
act as fiber optics and channel light through the layers of cells covering the rods and cones |
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Term
| what dominates visual fields? why? |
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Definition
dominant hand
dominant side of body generally has more nerves than the other side |
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Term
| what is an afterimage? what does it determine? |
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Definition
the ability to see remnants of an image while no longer looking at it
shows high color sensitivity |
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Term
| what form do odors come in? |
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Definition
| mostly airborne, some in liquid |
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Term
| what animal is the most sensitive to odor? what do they look like? what odor are they so sensitive to and how do they react? |
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Definition
the male moth
has feathery antennae, each strand has even tinier feathers and pores to increase surface area
only takes one molecule of pheromone to initiate the action potential in the ganglion
travel upwind to the female to mate |
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Term
| what do the olfactory cells look like? why? |
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Definition
spidery and spread out
surface area |
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Term
| what is the oldest sense? how do we know? |
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Definition
olfactory
when the brain grew forward, olfactory bulbs were the first grown |
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Term
| what is the least understood sense? what do we know about it? |
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Definition
olfactory (smell)
probably receptor sites for different types of molecules, or different types of smells |
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Term
| what scent are male humans most sensitive to? |
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Definition
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Term
| what scent are female humans most sensitive to? |
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Definition
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Term
| what is the most sensitive vertebrate to smell? why do they do it? |
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Definition
salmon
swim upstream to lay eggs to their exact birthplace
even though they die, they were able to survive there so they think its safe |
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