Sensory Flashcards
simple receptors are
nerve endings in tissues
simple receptors can be of two types
unencapsulated, encapsulated
unencapsulated receptors are
free nerve endings
encapsulated receptors are
tissue associated nerve endings
special senses are senses that
have a complex apparattus that support receptor cells
the special senses are (4)
olfactory, taste, labyrinth, (equilibrium/balance,/hearing), eyes
exteroreceptors tell you
what goes on outside the body.
what type of receptors are exteroreceptors
simple unencapsulated
encapsulated receptor types
pacinian corpuscles, meissners corpuscles
typed of unencapsulated receptors
mechanoreceptors, thermoreceptors, nociceptors
the most sensitve type of receptors are
free nerve endings
free nerve endings end in the
epidermis
type of receptors that wrap hair follicles
unencapsulated
unencapsulated receptors are located in the
skin, joints, viscera, oral cavity
area of the body with the most thermoreceptors
oral cavity
nociceptor threshold is
high
thermoreceptor threshold is
x
multimodal receptors
respond to all types; unencapsulated; chemo, thermo, noci
mechanoreceptor modality
stretch, displacement, pressure
thermoreceptor modality
hot > body p; cold < body temp
nociceptors modality
stronger stimuli required; can also be mixed modality;
meissners corpuscles innervate what tissue layer
dermal papillae in DERMIS; close to epidermis;
pacinian corpuscles innervate what tissues
deep dermis / hypodermis, viscera, joint capsules
sensory receptors tht wrap hair are also called
“associated” sensory receptors
encapsulated sensory receptors innervate what layer
dermis
pacinian corpuscles also called
lamellated
meissners corpuscles also called
tactile
lamellated corpuscles sense what
firm pressure; high freq vibration, tension, streth, NOT features; high threshold
lamellated corpuscles appearance
surrounded by schwann cells, large and white, squishy
tactile corpuscles respond to
low threshold; light pressure and vibration, ; light/discriminating touch,
tactile corpuscle appearance
branched to each receptor with single axon; multiple jumbled nuclei
two types of chemoreceptors
direct, distance
distance chemoreceptors
olfactory
direct chemoreceptors
taste
describe olfactory receptors
neurons with chemoreceptors on the dendrites in an aqueous layer
only chemicals that _ can be sesed by olfactory neurons
can be dissolved in aqueous layer
the aqueous layer is replaced rapidly so that
chemical stimuli is removed
describe the supporting epithelium of olfactory receptors
specialized respiratory; pseudostratified; NO goblet cells, NO cilia,
aqueous layer secreted by
glands in the lamina proprya
supporting olfactory tissues describe
columnar, assoc with basement membrane that replaces neurons
most olfactory epithelium is on what bone
nasal concha
difference between sharks/fish and terrestrial in olfaction
sharks do not have to generate fluids to wash away chemicals; thus are more sensitive to olfactory stimuli
describe shark olfaction
water flows into one sac and out of the other; water flows through water channels containing lamellae, nerves lead to olfactory bulbs
shark olfactory epithelium describe
like ours but arranged in layers; folded with water channels in between, containing lamellae. basal nuclei. nerves converge
hammerhead have _ sense of smell
stereo sense
primitive amphibian smell
have a nasal pit on the head; carris info from the mouth to nose.
terrestrial reptiles sense of smell
nose into air passages into skull into throat; rapid sniffs between major breaths
thing that most animals have but humans do not
vomeronasal organ
describe mammalian olfaction
high surface area, olf epithelium goes to olf bulb. large nasal cavities and high air flow
dog olfaction is x times more sensitive - why
100 thousand times; VNO, highly folded large surface area
the VNO is made of
olfactory epithelium
Taste receptors can pe found on
tongue, soft palate, oral cavity, epidermis
the 5 types of gustatory cells in taste buds
sweet, sour, salty, bitter, umami
taste buds are flushed by
saliva
saliva produced by
acini or salivary glands
acini are made of
simple cuboidal epithelium
three forms of acini
serous, mucoserous, mucous
taste receptor cells are called
gustatory cells
taste receptors are exposed to chemicals through
taste pores at peripheral end
types of taste buds
fungiform papillae, foliate, circumvillate
supporting cells in taste buds cqalled
sustentacular cells (supporting columnar epithelium)
average life of a taste bud
10 days
in fish, gustatory receptors are concentrated
anteriorly (towards head)
in elasmobranchs, tastebuds found in
only mouth and pharynx
olfactory epithelium is made up of x cells
pseudostratified squamous
three main cell types in olfactory epithelium
supporting cells, basal cells, brush cells/gustatory