BIO 111 Study Guide - Final Guide: Olfactory Bulb, Sensillum, Binocular Vision
30 Apr 2018
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Department
Course
Professor
Lecture 4/9/18
Acquired vs innate immunity
Defensive role of the gut microbiota - 3rd wave of immune defense
Behavioral immunity- individual organisms to detect the potential presence of
disease, causing parasites in their immediate environment, and to engage in
behaviors that prevent contact
Sense
Everything in nervous system is electrical
●Signals are converted into action potential
●Proton gradients
●A lot of filtering is done before the brain
●One way we keep stuff separated is to have different parts of the brain
specialize in different things
Vision
Vertebrates:
Melatonin- picks up signals through eye
●Pineal gland- as light gets darker, shoots melatonin so you get sleepy
●Very sensitive to light
Visual system-
●Humans- light energy goes through from of the eye and flips
●Don't want optic nerve where the light is strongest
●Certain waves of light we’re sensitive to
Retina-
●Eye’s are a bad design, light comes in a filters through different layers to
get to rods (night vision) and cones(color) (light sensitive cells in the retina)
(lot more rods)
○As you get closer to the fovea cones increase
●Color sensitivity
○Wavelengths overlap in sensitivity
●Ganglion cell- only cell that generates an action potential, take information
and may or may not send info to brain
●Amacrine cells (motion) and horizontal cells - filter inputs and send to
ganglion cells
Distribution of Photopigments
●Mainly reds (64%) & very few blues (4%)
●Insensitive to short wavelengths→ high sensitivity to long wavelengths
(yellow and orange)
●Center of retina (high acuity) has no blue cones
Theories of color vision
●Trichromatic theory- only have 3 color cones
○Cannot explain all aspects of color vision
○People with normal vision cannot see color combos
○Doesn’t explain after images
Dichromats- lost one of their cones
Monochromat- don't see any color only light and dark
●Opponent-process theory
○Three pairs of color receptors
○Explains after images
Color vision in other metazoans
●Other species see colors differently than humans
●Most other mammals are dichromats
Opsin- photosensitive pigment
Lecture 4/13
Insect vision
Ocelli: simple eyes that detect horizons and changes in light intensity (important
for diapause induction), no image resolution
Compound eye
●Mosaic vision: visual acuity greater when eye is small
Distance perception:
●Binocular vision is required
●Human eyes can converge on points in the distance
Tactile sense insects
●Sensilla (hair): mechanoreceptor that responds during deformation with a
charge from the nerve cell to the brain. For tactile senses, there usually only
one cell receptor per sensilla
Cockroaches have a big nerve cord for rapid transmission of nerve impulses->
extremely rapid movement
Insect taste
Chemoreceptors: respond to chemicals occuring on solid or in aqueous substrates
●Vertebrates: gustation
Insect smell (olfaction)
●Many species have acute ability to smell
●Olfactory chemoreceptors usually occur on the antennae
●Male moths move up towards the source of pheromones
In humans, approx 1000 types of olfactory receptors
Pheromones
●Used by animals as a form of communication
●Provides information identity, sexual receptivity
●Stimulate the vomeronasal organ
○Info from the VNO is sent to a special part of the olfactory bulb used
for pheromonal communication
Document Summary
Defensive role of the gut microbiota - 3rd wave of immune defense. Behavioral immunity- individual organisms to detect the potential presence of disease, causing parasites in their immediate environment, and to engage in behaviors that prevent contact. A lot of filtering is done before the brain. One way we keep stuff separated is to have different parts of the brain specialize in different things. Pineal gland- as light gets darker, shoots melatonin so you get sleepy. Humans- light energy goes through from of the eye and flips. Don"t want optic nerve where the light is strongest. Certain waves of light we"re sensitive to. Eye"s are a bad design, light comes in a filters through different layers to get to rods (night vision) and cones(color) (light sensitive cells in the retina) (lot more rods) As you get closer to the fovea cones increase.
