Ch. 18 Flashcards
sensation is sensory info arriving at
CNS
two types of senses
general and special
general senses includes
temp, pain, touch, pressure, vibration, and proprioception
general senses are found
throughout the body
general senses generally utilize tracts that are
ascending
special senses include
olfaction, gustation, balance, hearing, vision
specializer senses use tracts of
not ascending
special senses located
specific parts of body
for perception you need to be
conscious
to be able to detect stimulus you need
sensory receptor that are specialized for that area
free nerve endings are basically
dendrites
area monitered by recepter is the
receptive fields
sensitive receptive areas the fields are
small
tonic receptors are always
active
phasic receptors only become activated when
change occurs in conditions being monitered
strong stimulus look at
frequency of action potentials
ex. of tonic receptors
pain
adaption is a reduction in
sensitivitiy in the presence of a constant stimulus
peripheral adaptions is when
receptors or sensory neurons alter levels of activity
central adaption is when neurons remain active but
nuclei along the sensory pathway are inhibited
we can overcome the adaption of
central
classify receptors by
exteroceptors
interoceptors
proprioceptors
receptor classification according to stimulus type
chemicals, photons, sound waves, pain, temp, physical distortion
nociceptors are aka
pain receptors
nociceptors classified
free nerve endings with large receptive fields
nocicpeotrs respond to
extreme temp
physical damange
chemicalsw
nociceptors are common in
superficial skin, joint capsules, vessel walls
nociceptors are uncommon in
deeper tissues and viscera
referred pain is
visceral pain felt in areas far removed from site of damage bc primary sensory neurons converge on single tract
thermoreceptors structured as
free nerve endings
thermoreceptors are found in
dermis, skeletal muscles, liver, and hypothalamus
cold receptors are _x
3x more numerus than warm receptors
thermoreceptors utilize
lateral spinothalamic tracts
mechanoreceptors respond to
physical forces
3 calles of mechanoreceptors
tactile receptors
baroreceptors
proprioceptors
tactile receptors provide sensations of
fine/crude touch, pressure, and vibe
baroreceptors respond to
stretch and pressure in the hollow organs
proprioceptors monitor
position of joints and muscles
tactile receptors invole
sense of touch
3 types of tactile receptors
free nerve endings
root hair plexus
tactile merkels disc
freeve nerve endings for tactile receptors are in the
dermis
root hair plexus moniters
displacement of hairs
tactile discs are expanded
nerve terminals
tactile disc commumicates with
merkel cell in epidermis
tactile disc sense
fine touch and pressure
tactile disc description
tonically active with narrow receptive field
3 types of encapsulated tactile receptors
tactile meissner’s corpuscles
bulbous ruffini corpuscles
lamellar pacinian corpuscles
tactile meissner’s corpuscles detect
light, movement, and vibration
bulbous ruffini corpuscles detect
pressure and distortion of skin
lamellar pacinian corpuscles detect
deep pressure, pulsation, vibration
prop;rioceptors monitor
position of joints, tension in tendons/ligaments, and state of muscualr contraction
two types of proprioceptors
muscle spindles
golgi tendon organs
chemoreceptors detect
small changes in the concentration of specific chemicals/compounds
chemoreceptors respond to
substance dissolved in surrounding fluid
chemorecepotors in the
carotid and aoritc bodies detect changes ph,co2, o2
olfaction involes
detection of airborne chemicals dissolved in fluids that coat nasal membranes
olfactory epithelium contains
olfactory sensory neurons
supporting cells
basal epithelial cells
lamina properia contains
olf bowman’s glands
blood vessels
nerve
loose ct
olfactory sensory neurons possess up to
20 cilia
lamina propria does the
actively secrete mucus
olfactor recepotrs are VERY
specific
humans have the amount of smell genes
400
each olfaction receptor can bind to
1+ odorants
humans can distinguish
10,000 diff odors
gustation detects
tastants dissolved in saliva
taste buds found throughout
oral cavity on lingual papille
gustatory cells are actually
epithelial cells
taste buds contain
gustatory epithelial cells
basal epithelial cells
gustatory epithelial cells have multiple
types within each taste bud
gustatory epithelial cells project
microvilli into taste pore
perception of taste involves
sensory data regarding the texture and temp of food from CNV
taste bud CN order
CNVII facial nerve
CNIX glossopharyngeal
CNX vagus
80% of taste is
smell
gustatory discriminates
sweet
sour
salty
bitter
umami
water
sweet gustation is by
sugars, alcohols, AA and lead salts
Sour gustation is by
acids
salty gustation is by
metal ions
bitter gustation is by
alkaloiods, quinine, nicotine, caffeine, and morphine
unami gustation by
glutatmate and aspartate
savory
water gustation by
no flavor but present in pharynx
on tongue there are how many more receptors for acids than sweets
1,000x
10x more receptives for
bitter than for acids
taste is not regionalized on the
tongue
gustatory receptors also fiound on the
BODY
cells that line trachea can detect toxins with
bitter receptors
