Exam 2: Senses Flashcards
sensory receptors are specialized cells that…
- monitor external and internal conditions
- cover a specific area (sensory field)
- detect stimuli or changes
- send information to the CNS
all receptors function in _____ but no all are involved in _____
sensation
perception
perception
the conscious awareness of the sensation
ex: dorsal column tract
2 classifications of sensory receptors
general sense or special senses
general senses
-found in many places throughout the body
-simple in structure
T sensation, pressure, stretch receptor
special senses
- localized in one area
- complex in structure (eye - so many layers)
4 types of general sense receptors
- mechanoreceptors
- thermoreceptors
- nociceptors
- chemoreceptors
mechanoreceptors
respond to pressure, vibration, physical distortion
- monitors a cell or tissue fiber looks to see if compressed or stressed
- tactile receptor with CT around it, if pressure it gets compressed and sends signals
-hearing is special sense but uses mechanoreceptors - tympanic membrane and when hair cells distorted
thermoreceptors
respond to changes in T
-heat exchange - not giving the actual T but if it gets colder or hotter
nociceptors
respond to tissue damage as a pain sensation
- when cells destructed - tearing, chemical burn
- some fast, some slow
chemoreceptors
respond to dissolved chemicals
-taste, smell, pH
adaptive ability of receptors : fast adaptors
phasic
respond to change
only triggers when there is a change
adaptive ability of receptors: slow adaptors
tonic
send continual info to CNS
example of adaptive ability when putting a shirt on
phasic is stronger when putting shirt on and then tonic after it has been on you may not recognize you are wearing a shirt
3 types of mechanoreceptors
baroreceptors
proprioceptors
tactile receptors
baroreceptors
free nerve endings
found embedded in walls of distensible organs: digestive system, lungs, colon, bladder
- monitor changes in elastic tissue
baroreceptors - nerve endings - blood vessels
carotid and aortic sinus
- both chemo and baroreceptors
- monitors blood pressure
- vagus nerve will send this signal, some glossopharyngeal to see if P needs to inc or dec
baroreceptors - digestive system
locally - stretch receptors
when stomach emoties into SI it sends signals to get secretions from oancrease and gallbladder, does not happen without stretch receptor signaling
baroreceptors - lungs
need to have feedback to know it is working
stretch responders only respond when stretched- when you inhale you could see how long the signal is
baroreceptors and age - rigidity in walls of blood vessels - isolated systolic hypertension
high BP pushing blood into same vessel but it is resistant to expanding now
reduces recoil ability-diastolic P may dec
- not enough blood, fainting, fall risk
proprioceptors
-nerve endings wrapped around muscle or collagen fibers and then encapsulated by connective tissue (spindles and tendon organs)
tendon organs
tendons do not stretch, they have tension on them
gives idea both unconscious and conscious of what tension is on ligaments and tendons
what the muscle tone and tension is
-respond to patellar reflex
joint receptors
branched nerve endings encapsulated by connective tissue and embedded in joint capsule
where are proprioceptors located
embedded in muscle, tendons, ligaments, joint capsules
tactile receptors and what are the 2 types
touch receptors
in the integument - skin
encapsulated by connective tissue
- superficial and deep
superficial tactile receptors
boundary of epidermis and dermis
merkels discs and meissners
merkels discs
tonic
fine touch and pressure
interact with special epithelial cell
if lean on table, the entire time your arms are there there is P compressing the discs and you constantly get signals sent - constantly aware you are leaning on it
Meissner Corpuscles
highly phasic
fine touch and pressure
only these will respond when you put a piece of paper on your arm - feel at first butu then it goes away
different sensitivity
deep tactile receptors
more into dermis near subcutaneous
ruffini, pacinian corpuscles, krause
ruffini deep tactile receptors
tonic
deep pressure
ct wrapped around so if compressed it keeps sending signals like Merkel’s discs, BUT instead of a separate cell, one wraps around it
thermoreception***
Pacinian corpuscles - deep tactile receptor
phasic
deep pressure
- like an onion ring - nerve fibers stuck inside
- as P is put on the ring it slides down from the P - once you stop sliding the rings, the signals stop being sent
connective tissue concentric rings
Krause end bulbs - deep tactile receptor
tonic
deep pressure
specific regions: conjunctiva, oral mucosa, genitalia, epineurium
thermoreception**
thermoreceptors
free nerve endings
located in dermis, skeletal muscle, AND hypothalamus, AND liver (largest organ in core)
phasic
“cold” receptors: 10-35C (50-95F)
“warm” receptors: 30-43C (85-110F)
- utside this range is detected by nociceptors and encapsulated deep receptors
fast pain
myelinated type A fibers
large diameter-like big highway
sharp, acute pain
mechanical or thermal
slow pain
unmyelinated type C fibers
mechanical, thermal, metabolic-visceral pain
dull, long lasting pain
interacts with cells for inflammation
what do chemoreceptors respond to
either water soluble (mostly) or lipid soluble chemicals
carotid and aortic bodies
carotid and aortic bodies
chemoreceptors
monitor pH, CO2 and O2 in blood
(more critical to monitor CO2 than O2)
carotid body - CN 9 glossopharyngeal
aortic body - CN 10 vague
olfaction
smell
where are olfactory cells located and what type of receptor are they?
located in superior region of nasal cavity
chemoreceptors
odorant to receptor identification
one receptor will respond to one stimulus but one odorant can stimulate many receptors
how do you interpret a smell
a combination of the receptor stimulation
olfactory receptors send information to glomeruli which…
compile the stimuli pattern and send the info to the mitral celsl
mitral cells
get info from glomeruli and increase the intensity of the stimulus and direct the impulse to the temporal lobe for identification and response
ACE2 receptor
smell
angiotensin converting enzyme
when alter and keep in more water and salt you activate this enzyme
in sustenacular membrane - does not destroy olfactry receptors but when the supporting cells are damages it then effects the olfactory cells
gustation
taste
series of receptors with supporting cells
chemoreceptors
tastants dissolved in saliva
pits of taste buds
where the saliva is carrying tastants to the pore where we have receptors and support cells
circumvallate
folate
fungiform
circumvalllate: back of tongue
folate: side of tongue
fungiform: on surface of tongue
where are gustatory receptors located
tongue, pharynx, larynx
sweet
sugar - glucose, fructose, sucrose
fructose gives strongest response
artificial sweeteners have one epitope that will make you think it is sugar
sour
responds to acidity (hydrogen ion concentration)
vinagrettes, sour patch kids
salty
responds to Na+ and K+
some people need a salt substitute and cannot have NaCl so they give KCl (nothing artificial about the salt substitute)
potassium does not make you retain water
bitter
responds to alkaloids (quinine)
most diverse category!
some people more sensitive than others - cilantro
umami
responds to amino acids
protein
are taste buds localized to specific regions
no
when do taste buds turnover
constantly - approx 7 days to fully express it again if burn roof of mouth
flavor
combination of taste and smell
bitter receptors in bronchi
do not detect taste
they stimulate bronchodilation response to clear respiratory tract
what does the pharynx have receptors for
water
yes water has taste
if a person had an upper respiratory infection that blocked nasal passages, what about their taste?
blocked nasal passages so not getting to recepotrs
will have basic taste but will not enjoy flavors
a phenylthiourea taster vs a non taster for common flavors like saccharin and caffeine
less thrilled about drinking coffee - bitter
trigeminal nerve involved in taste and T sensation. Explain variations in liking spicy food - not necessarily to taste buds
if grew up eating spicy foods all the tme - tolerance
makes you sweat
patients blood pressure medication leads to dry mouth - taste?
lacking saliva needed for enzymes to keep healthy mouth
will not taste good
functions of outer ear (3)
- collects sound waves
- directs sound to tympanic membrane
- converts compressed air pressure to vibration
middle ear functions (3)
- mechanical vibrations transmitted to ossicles
- mitigation of loud noises
- eustachian tube equalizes pressure on tympanic membrane
inner ear functions (3)
- receptors for hearing and equilibrium in cochlea
- fluid vibrations stimulate specific hearing receptors in cochlea
- fluid movement in semicircular canals and vestibular trigger responses in equilibrium receptors
malleus (hammer)
attaches to tympanic membrane
incus (anvil)
intermediate ossicle
stapes (stirrup)
communicates with inner ear
pharyngotympanic tube
- beginning of it is composed of bone
- lower part is cartilage
- bony part remains open but artilage closed - open when swalloing,yawing, chewing
- mucosa of tube is ciliated columnar epithelium containing goblet cells
divisions of inner ear
semicircular canals
vestibule
cochlea
semicircular canals
anterior, posterior, lateral
houses angular motion receptors
vestibule
utricle and saccule
houses linear movement and acceleration receptors
cochlea
snail shell
houses hearing receptors
oval window
allows communication with the stapes
transmitting vibrations to internal fluid
round window
relieves pressure as the fluid is non-compressible
what is the bony labyrinth filled with
perilymph
perilymph
- produced by vasculature of periosteum - consistency of CSF or ECF without proteins
- it surrounds the inner membranous labyrinth
what does the membranous labyrinth contain?
endolymph
produced by vasculature in cochlea and drained through endolymph sac into venous sinus system
what ion has high levels in endolymph
K+ - consistency closer to intracellular fluid without proteins
where is the organ of corti
central cochlear duct and it contains endolymph
the scala tympani and scala vestibuli contain what?
perilymph
does the tectorial membrane bounce?
no
damage to inner hair cells
lose ability to hear the certain frequency
damage to outer hair cells
can still distinguish frequency but lose amplification ability
stapes vibrations travel through _____ distorting the cochlear duct
scala vestibule
distortion of the cochlear duct sets up vibrations in the _____
basilar membrane
basilar membrane
thick membrane that supports organ of corti
movement stimulates hearing receptors
vibrations of the endolymph distortion are transmitted to the ____ causing distortion of the ______
scala tympani
round window
what is the rigid, collagen rich membrane located immediately above the hair cells
tectorial membrane
stereocilia
- in a single row of IHC they are short
- trigger the nerve when distorted in bouncing against the tectorial membrane
OHC and stereocilia
longer, curved stereocilia
longest cilia embedded in tectorial membrane
when stimulated OHC contract pulling the organ of corti closer amplifying effect on the IHC
damage to IHC results in
sensorineural deafness
- lose ability to hear at a specific frequency
damge to OHC results in
inability to discriminate sounds
nerve deafness of a patient with a cochlear implant, what is damaged
hair cells
crista ampullaris
receptors at base of semicircular canals
- covered in endolymph - how the endolymph moves and distorts the cupulla
one big kinocillium - bends towards it it depolarizes, bends away - hyperpolarization
angular motion
equilibrium is associated with what system
vestibular system - works on eye movements unconscious ocular saccades - nystagmus present
how does alcohol effect endolymph
chanegs the consistency - they can no longer unconsciously control balance so you see then consciously trying to balance when unconscious is shot
2 regions in the vestibule with macula
utricle and saccule
otoconia
calcium bicarbonate crystals embedded in gelatinous layer with hair cells
- has cilia kinocilium and stereocilium
as you move you put drag on these crystals which distorts the cilia - people may get vertigo
both the utricle and saccule have midlines known as
striola
kinocilium in utricle
point towards the striola
kinocilium in saccule point
away from striola
utricle is what you depend on when you are in what position
upright
saccule is what you depend on when you are in which position
laying down
functions of vestibular system
- monitors position of body
- sends info on body orientation and movement to areas of brain like cerebellum and cerebrum
- allows for compensation, adjustment, planning of motor movements
cristae ampullaris functions
- works in pairs
- each receptor has its own kinocilium
- bending of hairs towards kinocilium - depolarization, away-hyperpolarization
- angular movement causes depolarization of one pair and hyperpolarization of others
