Lecture 6: nervous system and perception

Question 1

Stigma eye

Answer 1

• protozoan
• small opaque area in front of light-sensitive pigments
• provide animals with directional information
• compare light coming from 2 or more directions

Question 2

pinhole eye

Answer 2

• eye cup with tiny opening
• receive precise but INVERTED image

DISADV. : small amount of light enter, bending of light reduce quality.

Question 3

lens eye

Answer 3

• Lens in dense
• bends and focus the light more than pinhole eye
• rods: active at night
• cones: active daytime

DISADV: alter lens and change focal point, defects can occur (far-sighted or astigmatism)

Question 4

compound eye

Answer 4

• typical for insects (fly)
• many eye cups, each with a lens

ADV: low weight and volume for bees,flies, etc.
flicker fusion rate

Question 5

flicker fusion rate

Answer 5

can distinguish 2 separate images closely spaced in time.

Question 6

color discrimination

Answer 6

bees can see UV light, blue, yellow-green

humans: blue, yellow-green and yellow-orange

Question 7

lateral inhibition

Answer 7

interaction between receptors in retina, causes inhibition in certain receptors to emphasize contrast

Question 8

feature detectors

Answer 8

wired to sort out specific stimuli and exaggerate their differences

Question 9

sound

Answer 9

vibration of molecules

Animal hearing, 0.1- 100,000 Hz

Question 10

particle-detector ear

(invertebrates)

Answer 10

antennal hairs
lateral-line organs
body hairs
subgenual organ

Question 11

1st limitations to particle-detector ear?

Answer 11

limited resonance frequency, deaf to most sounds

Question 12

overcome resonance frequency by?

Answer 12

using different detectors of diff. resonance

Question 13

2nd limitation

Answer 13

cannot distinguish quiet sound or loud sound close to peak resonance

Question 14

3rd limitation

Answer 14

deaf to sounds where detector is pointed, sensitive to sound from the side.

Question 15

pressure gradient ear

Answer 15

membrane respond to difference in pressure b/w 2 openings of cavity

ADV: more sensitive and broader frequency, ideal for smaller animals

Question 16

pressure difference ear

Answer 16

membrane thin, low mass, stretched across a high-mass cavity

Question 17

low or high frequency travel

Answer 17

low travel faster due to longer wavelengths

Question 18

doppler effect

Answer 18

movement of sound toward or away from listener

Question 19

echolocation

Answer 19

performed by bats, marine mammals

3 classes of bat cries:

Question 20

echolocation

Answer 20

performed by bats, marine mammals
3 classes of bat cries: 
- frequency modulated
- constant frequency
- measure doppler effect of CF echo of it's cry, to determine their speed. 
-

Question 21

taste

Answer 21

salt
sweet
sour
bitter

Question 22

5th taste receptor

Answer 22

umami MSG

Question 23

taste receptors for insect

Answer 23

same four taste receptors on each hair of feet

they find food by stepping on it

Question 24

olfaction

Answer 24

butyl mercaptan –> skunk like odor
humans have 5 millions, dogs have 100-300 millions receptors
animals use odors to synchronize ovulation in females

Question 25

Thermal location

Answer 25

“see” infrared light/ heat with detector

rattle snake strike anterior of mice

Question 26

electrolocation

Answer 26

detect electric field

innervated bulbs in some fishes

Question 27

magnetic location

Answer 27

pigeons sense earth’s magnetic field

Question 28

circadian rhythm

Answer 28

• crickets know when to sing, independent to environmental cues
• visual signals need to entrain cycle
• biological clock occur in optic lobe