Sensory adaptations Flashcards
what are some sensory adaptations
-auditory (hearing)
-vision (sight)
-gustation (taste)
-traction (touch)
how does the neuron transmit info
-receives stimulus and gets amplified
-moves down the dendrite
-makes electrical signal
-travels up the axon to the next neuron
what is the auditory ability of dogs
-dogs can hear at higher frequencies than humans
-40,000 cycles/seconds in dogs (20,000 in humans)
-structure of a dogs ears enable sounds to be heard 4x further than human
auditory pathway of dogs ears
external auditory meatus–> tympanic membrane–> malleus incus staples–> oval window membrane–> vestibular canal–> cochlea–> auditory nerve–> brain
auditory testing in dogs
-brainstem auditory evoked response (BAER) testing detects unilateral or bilateral deafness
-congenital deafness and adult-onset deafness
hearing range in cats
-hearing in an important sense for locating prey and their young when they go astray
-cats can detect sounds up to 80,000hz and as low as 20khz (wider range than dogs)
hearing adaptations in the cat ear
-the pinna aids in the detection of sound
-it can rotate up to 180 and they can also move independently
-at a distance of 1 meter a cat can distinguish between two sounds 3 cm apart
vision of dogs
-more rods than humans
-3x more sensitive to low light
-movement and shape
different photoreceptors
-rods (low intensity, night vision)
-cones (bright light, high intensity light, colour resolution)
how is vision processed
-light stimulus
-bounces in back of the eye
-goes to visual cortex of brain
tapetum lucidum
-layer of reflective cells behind the retina in cats, dogs, and other animals
-helps capture additional light for night vision
-disadvantage: scatters of light makes it more difficult to resolve details of images
cones in humans vs dogs vs cats
-humans have 3 kinds
-dogs have 2 types of cones they dont see red and orange spectrum
-cats have 3 cones but the red + orange in weak
canine field of vision
-head shape affects field of vision
-brachycephalic breed- 200
-dolichocephalic breed- 270
depth perception
-affected by degree of binocular overlap which is greater in flat-faced dogs
-average binocular vision is dogs is 30-60 degrees
-humans 140 degrees
-wider=less depth perception
vision in cats
-cats eyes are large for their size
-set forward to provide a wide field of binocular vision (120)
nictitating membrane
-third eyelid
-sits in the corner of their eyes and clears out dust
olfactory neurons
-olfactory epithelium (olfactory receptor-first order neurons)
-olfactory bulb (mitral cell- second-order neurons)
what olfactory organ is an extension of the brain
olfactory bulb (mitral cells)
olfaction neuron quantity of dogs vs cats vs humans
220 M-2billion, 200M, 12-40M
length of olfactory epithelium lining nasal passage way of dogs vs cats vs humans
150cm2, 20cm2, 3-4cm2
sniffing
-disrupts normal breathing pattern to allow inhaled molecs to remain in the nasal passage longer
-series of rapid and short inhalations and exhalations
olfactory adaptations that dogs have
-moist nose
-more independently moving nose (stereoscope)
-slits in the nose to not disrupt air going in when breathing out, new air isn’t diluted
-they know which side nostril the scent is coming from
-shelf of epithelium in nasal cavity
vomeronasal organ
-composed of a pair of fluid-filled sacs with receptor cells
-present in both dogs and cats
-detects pheromones
-chemoreceptor organ
-first processing stage of the olfactory system
-neural receptors are different than in the main olfactory system
-impulse sent to the brain
cat olfactory
-olfactory receptors in the olfactory epithelium are up to 5x more than humans
-have vomeronasal organ
-can have flehmen response
-30-50% exhibit plant-induced olfactory behaviour (cat nip)
what does catnip contain
nepetalactone which causes agitation, head shaking, salivation
what are the 5 things possible to taste
-sweet
-sour
-salty
-bitter
-umami
taste in dogs
-dogs have ~1700 taste buds on the tongue; ~9000 in humans
-most abundant taste buds are sugar sensitive
-second most in acid
taste bud mutations in dogs
-NSDTR have disrupted genes for bitter
-pug have disrupted genes for sweet
taste in cats
-fewer tastebuds ~470
-they use smell and taste in selecting food
-can detect salty, bitter, and acidic flavours
-limited ability to taste sweet
what does the cats filiform papillae help with
rasping the meat from the bone
how do dogs drink
-curl their tongue and scoop water into their mouth
-throwing water into their mouth and catching it
how do cats drink
-curl tongue
-tongue doesn’t dip below the surface
-the tongue touches the surface and creates a column of liquid
cat drinking “lapping” cycle
-tongue is lifted drawing liquid up
-liquid is trapped in the ruggae (ridges) of the palate
-tongue helps trap the liquid
-swallowing occurs every 3 to 17 cycles
touching in cats
vibrissae (whiskers) are important sensory organ
vibrissae in cats
-found on muzzle, above eyes and on the back of the front wrist
-movable
-provide sensory information about position of prey in dim light
-upper and lower rows
-3x deeper
-used for air movements aswell
cats and balance
-vestibular apparatus (ie. semicircular canals) in the inner ear more developed in cats
-can walk across fence rails, etc
cats falling
-due to great balance
-they land feet down almost always
-start gaining the skill around 6-7 weeks old
