Lecture 20 - senses II Flashcards Preview

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Flashcards in Lecture 20 - senses II Deck (30)
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1
Q

can most invertebrates hear?

A

no

2
Q

What do some insects use to detect sound?

A

Tympanic organs

3
Q

how does a Moth’s detection of bat ultrasound work?

A

A1 & A2 receptors: different sensitivity
A2 signals ‘too loud’
(bat too close -> moth drops)

4
Q

What are the key structures in Vertebrate hearing?

A
Pinna
Tympanic membrane
Middle ear bones
- Malleus
- Incus
- Stapes
Inner ear
Oval window
Cochlea
- Tectorial membrane
- Hair cells
5
Q

how does the inner ear detect sounds?

A

Fluid moves hair cells of Organ of Corti (in cochlea), causing the Basilar membrane & hair cells to
oscillate.

6
Q

The location of Resonance of basilar membrane allows the ear to determine?

A

frequency

7
Q

what are the different Hair cells of Organ of Corti?

A

Outer hair cells: attached to tectorial, mainly amplify

Inner hair cells: free in fluid, mainly detect

8
Q

What frequency range can most mammals hear in?

A

<20 kHz

9
Q

How do owls detect vertical angles?

A

Asymmetrical “ear flaps” and placement of ear canals

10
Q

How do males and females differ in hearing loss?

A

females lose lower freq,

males lose higher freq

11
Q

What are Bats hearing adaptations for echolocation?

A

high pitch for high temporal
resolution
modified larynx

12
Q

What is Photoreception

A

sight/light detection

13
Q

What makes soft-furred tree mice unique?

A

convergent evolution: tree mice use Ultrasonic sounds to navigate environment

14
Q

How does Photoreception work?

A

There are Light-sensitive pigments (rhodopsins = retinal + opsin). Light causes photochemical reaction with retinal (carotenoid derivative of vitamin A)

15
Q

What is the signal pathway of Photoreception?

A

Isomerisation of retinal -> opsin protein ->

excitatory cascade -> nerve signal

16
Q

What are lights key traits?

A

Direction
Colour (wavelengths)
Polarity

17
Q

What is the structure of compound eyes?

A

Many sensilla with lens and receptor cells

ommatidia

18
Q

Apposition eyes

A

each ommatidium (with lens and photoreceptor) acts
independently.
Good for bright conditions

19
Q

Superposition eyes

A

transparent zone below lens where light from several
ommatidia reach same photoreceptor.
Good for dark conditions
Prevent damage in bright conditions using pigment to block side of ommatidium

20
Q

Neural superposition

A

Apposition eye with lenses and nerves that results in

seven times stronger signal

21
Q

What causes the blindspot in vertebrate eyes?

A

Optic nerve passes through retina

22
Q

How do Vertebrate eyes work?

A

light is refracted by the cornea and lens. Light then passes through neurons and photoreceptors.

23
Q

What are the two types of photoreceptor cells?

A

Rods and cones

24
Q

what is the Fovea?

A

The area with the highest density of cones

25
Q

What are the rods in the eye for?

A

Low light levels

26
Q

What are the cones in the eye for?

A

Bright light, high resolution

27
Q

What is the tapetum lucidum?

A

The structure that reflects the light back into the receptors allows for increased vision in low light.

28
Q

What is Binocular vision an adaptation for?

A

hunting

climbing

29
Q

What advantage does having Binocular vision?

A

Gives an increased perception of depth?

30
Q

How does Binocular vision work?

A

Visual cortex compares two images