ANBI 360.3 Lecture Notes - Lecture 17: Depth Perception, Retina, Nepetalactone
20 Jun 2018
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LECTURE 17!
Care and Grooming for health!
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Sensory Adaptations!
Hearing!
BAER testing ( hearing testing) detects unilateral or bilateral deafness!◦
congenital deafness and adult onset deafness!◦
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hearing in cats!
hearing is an important sense for locating prey!•
cats can detects sounds up to 80,000 hz and as low as 20hz ( wider range than dogs)!•
the pinna (outer ear flap) of the ear aids in sound collection!•
pinna can rotate up to 180 degrees!•
at a distance of 1 meter a cat can distinguish between two sounds 3cm apart !•
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dogs can hear at much higher frequencies than people!•
40,000 cycles/ second in dogs- 20,000 in humans!•
structures of a dogs ears enable sounds to be heard 4X further than humans!•
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Vision in dogs and cats!
more rods than humans ( able to see in dim light)!•
3X more sensitive to low light!•
movement and shape!•
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tapetum luicidum is a layer of reflective cells behind the retina in cats , dogs, and several other •
animals!
helps capture additional light for night vision!•
disadvantage: scatter of light make it more difficult to resolve detail of images !•
creates more scatter!◦
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field of vision!
head shape affects field of vision!•
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depth perception!
affected by degree of binocular overlap which is greater in flat faced dogs!•
average binocular vision is 30-60 degrees!•
humans are at 140 degrees!•
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cats eyes are large for their size!•
set forward to provide a wide field of binocular vision (120 degrees)!•
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much lower density of cones than humans!•
dogs can see colour in the blue to green range but no orange to red!•
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Olfactory adaptations!
can smell further!•
detect more!•
wider range of smells!•
on handout!•
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