senses Flashcards
define sensory transduction
the conversion of energy in a stimulus to action potentials in a nerve
what are sensory receptors
cells that transmit signals to sensory neurons
what is receptor potential
an initial response of a receptor cell to a stimulus, consisting of a change in voltage across the receptor membrane
what is a sensation
when sensory receptors and nervous system receive and represent stimulus energies from the environment
what is perception
the process of organizing and interpreting sensory information. allows us to recognize meaningful objects and events
what are the two main types of receptor cells in senses
those that are separate cells vs those that are free nerve endings on an afferent neuron
what is the difference between a receptor cell and a cell surface receptor
receptor cells are found in the cytoplasm or on surface that receive signals
cell surface receptors are embedded in the plasma membrane and receive signals
classification of sensory receptors and their stimulus that they detect
chemoreceptors detect chemicals
mechanoreceptors detect touch, stretch, etc
photoreceptors detect light
thermoreceptors detect temperature
nociceptors detect pain
define modality
specific type of sensation felt (light, touch, sound)
define quality of sense
distinct characteristics within a modality (pitch of noise, soft or hard touch)
what are the main types of information that needs to be sent to the brain about a stimulus
type of stimulus, location, magnitude, and duration
what is the labeled line theory
that the CNS determines the type of stimulus based on receiving input from all sensory cells activated by that stimulus
how does the sensory system encode stimulus intensity
frequency of action potentials, number of receptors activated a stimulus
define receptive field (location of stimulus)
a specific region of sensory space in which an appropriate stimulus can drive an electrical response in a sensory neuron
define sensory projection
any areas of the cerebral cortex to which information is transmitted by the afferent fibers from sensory receptors
define projection pathways
connect the cerebral cortex to the thalamus, brainstem, cerebellum, and spinal cord
what is phantom pain
pain experienced in the area of a body part that has been surgically removed
what does the frog experiment tell us about sensory projection
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define phasic receptor (duration)
rapidly adapting receptors. they respond quickly to stimuli but stop responding upon continuous stimulation.
define tonic receptors (duration)
they are slow adapting. they will respond to the stimulus as long as it persists and produce a continuous frequency of action potentials
what info does tonic receptor provide
they convey stimulus duration and intensity
what info do phasic receptors provide
convey information about the changes to the stimulus such as intensity
define adaptation
the change in sensation intensity with a continued stimulus, due to adjustments of the receptors sensitivity
define interoreceptor
sensory receptor which receives stimuli from within the body
define exteroreceptor
sensory reception which receives external stimuli
define special senses
smell, taste, vision, hearing, equillibrium
somaesthetic senses (general senses)
body senses including touch, temperature, pain
what is the difference between general senses and special senses
general senses have receptors widely distributed throughout the body and skin
speical senses have more specialized receptors and are confined to structures in the head (like eyes/ears)
what are cutaneous receptors
receptors in the dermis that make the skin sensitive to touch, pressure, pain, and temperature
what are proprioceptors
detect body position in space and movement
- include muscle spindles, golgi tendon and organs
what are the two types of receptors for general senses
cutaneous and proprioceptors
name the different types of cutaneous receptors
touch: tactile disc, hair receptor, ruffini corpuscle
pressure: tactile corpuscle and lamellated corpuscle
temp and pain: free nerve endings
what is pain
unpleasant sensory and emotional experience associated with actual or potential tissue damage
what is the purpose of pain
to indicate tissue injury
what role does reticular formation play in pain
causes arousal
what role does the somatosensory area play in response to pain
gives sensation
what role does the hypothalamus play in response to pain
gives physiologal responses
what role does the limbic system play in response to to pain
gives emotional response
what is referred pain
pain felt in a part of the body other than the actual source
what is the clinical significance of referred pain
if you are having referred pain, you should know to go to a doctor and report the pain
define analgesic
drug that relieves pain, not good for chronic pain, derived from synthetics or opium poppy, very dangerous (opioids)
what is spinal gating
stops pain at the dorsal horn
whar are endogenous opiates
chemicals produced in the brain that block the perception of pain and increase feeling of wellbeing (produced in pituitary gland)
describe the danger of opiate painkillers
very addictive, depress breathing centers which results in death, fatal overdose potential, fentanyl is deadly, most dangerous when mixed with alcohol
how are opiate painkillers related to enkephalins
enkephalins possess all the properties of morphine opiates, but are made in the brain naturally.
how do opiates cause death
respiratory depression
why is medical marijuance of interest in pain management
more effective for chronic pain, no depression of breathing, no fatal overdose, no liver damage
what are NSAIDS
non steroidal anti inflammatory drugs
can NSAIDS cause overdose or harm to body
yes, overdose and liver damage and stomach damage
define the modalities of chemical senses
gustation (taste) and olfaction (smell)
taste (gustation)
detects dissolved chemicals on the tongue
what is the anatomy associated with taste receptors
papillae (bumps), taste buds, taste pores, taste hairs, and supporting cells
what are the five taste sensations
sweet, sour, salty, bitter, umami
olfactory
sense of smell
anatomy of olfactory system
look at powerpoint
anatomy of the ear
outer, inner, middle ear
be able to label ear structure
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what are the functions of the different regions of the inner ear
vestibule: to perceive movement and acceleration to maintain equillibrium
semicircular canals: help keep balance with the liquid inside
cochlea: sense of hearing and sound waves
what is sound
disturbance that travels through a. medium as a longitudinal wave
what produces sound
vibrations
define amplitude of sound
intensity of sound energy (loudness)
define frequency of sound
pitch of the wave (high or low)
how are amplitude and frequency coded by the cochlea
assistance of hair cells
define decibel
unit of measurement for intensity of sound
how does the sound intensity that causes ear damage relate to the intensity that causes pain
hearing becomes uncomfortable above 110 decibel and becomes pain after 130 decibels
know the anatomy of the inner ear
picture
define endolymph
fluid within the membranous labyrinth
define perilymph
fluid within the bony labrynth
function of macula utriculi in ear
detects linear accelerations
function of macula sacculi
detect vertical acceleration
function of otoliths in ears
sense rotational head movements, linear and vertical acceleration and gravity
function of ampullae
sense of spatial orientation
function of cupula
also a sense of spatial orientation and head movements
what are hair cells
sensory receptors for sound
structure of hair cells
picture
what senses do hair cells provide
hearing and balance
how do hair cell structures allow such different functions
they convert mechanical energy into electrical energy that is transmitted to the nervous system to decide if it is hearing or balance
what are sterocilia
short hair cells in the cupula
how are K+ channels gated by the sterocilia
bending of the sterocilia toward the kinocilium opens the ion channels
how does sound cause bending of the sterocilia
the sound waves bend it depending on the amplitude and frequency
what is the role of tectorial membranes
determining the sensitivity and frequency of hearing
what is the role of basiiar membranes in hearing
supports hair cells, allows brain to interpret sound
define auricle
outer ear
function of auricle
collect sound waves
function of auditory canal
serves as a passageway for sound to reach the eardrum
function of tympanum
received sound vibrations and transmits those vibrations to the middle ear
function of ossicles
transmit and amplify vibrations from the eardrum to the inner ear
function of oval windows
carry sound from middle ear to inner ear
function of round windows
equalizes pressure as sound is going through the ear
function of organ of corti
contains hearing receptors
function of scala tympani
conducts sound vibrations to the cochlear duct
function of scala media
receptor organ for hearing
how do loud sounds damage the ear
overworks the hair cells which makes them die
differentiate between sensorineural and conductive hearing loss
sensorineural: abnormal development or damage to the hair cells
conductive: interference in transmission of sound from external auditory canal to inner ear
what is tinnitus
ringing in the ears
what are some causes of tinnitus
loud sounds, extreme stress or trauma, degeneration of hair cells, some medications
define cochlear tuning
measures how large an input is required to give out an output level
purpose of tympanic reflex
protect inner ear from overstimulation from loud sound
define static equillibrium
sense of which direction is pulling on the body
define linear acceleration
moving of the body in a straight line
define angular acceleration
not in a straight line (head rotation)
which part of the ear detects angular acceleration
semicircular ducts
which part of the eat detects linear acceleration
vestibular apparatus and semicircular ducts
which part of the ear detects static equillibrium
vestibular apparatus
what is the electromagnetic spectrum
the range of all types of radiation
(radiation is energy that travels and spreads out as it goes)
what wavelengths form visible light
380 nm to 750 nm
which end of the light spectrium senses blue
the lower number (380)
which end of the light spectrium senses red
the higher number (700)
which end of the spectrum has higher energy
the lower numbers
what is UV light
invisible light that lies beyond violet, has higher energy and shorter wavelengths than visible lught does
define infrared light
invisible light that lies beyond violets has higher energy and shorter wavelengths
know the anatomy of the eye
picture
function of extrinsic eye muscles
responsible for movement of the eye along the horizontal movement (abduction or adduction), vertical (elevation or depression), and torsional (toward or away from nose)
functions of intrinsic eye muscles
control the movements of the lens and pupil and vision
functions of tunics in eye
protects the eyeball and maintains its shape
functions of ciliary body in eyes
produces the aqueous humor
functions of pupils in eyes
lets light into the eye as the muscles of the iris change shape
function of iris
regulates the amount of light that enters into the eye
function of suspensory ligaments
maintain and support the position of the eye in a normal upward and forward position within the orbit.
function of lens
transmit and focus the lught onto the retina in order to create a clear image of images in the distance
function of anterior and posterior chambers in eye
both are filled with aqueous humor (watery fluid) that provides nourishment to interior eye and helps keep eye inflated
function of vitreous body
maintains the round shape of the eye
function of retina
captures the light that enters the eye and helps translate it into the images you see
function of optic disk
transfer signals from photoreceptors of the eye to the optic nerve, allowing us to see
function of macula lutea
responsible for the sharp, detailed central vision
function of fovea centralis
allows for high visual activity
role of ANS is controlling pupils and lens
- pupil size, lens accomodation, ocular circulation
what is the photopupillary reflex
reflex that controls the diameter of the pupil
list optical vs neural components of the eye
neural: retina and optic nerve
optical: cornea and lens, iris, retina
define refraction and why it is important in the eyes
bending of light to produce a focused image on the retina, it makes it possible for us to have lenses and magnifying glasses and rainbows
where does the greatest amount of refraction occur in the eye
the cornea
what is the role of the lens and how does it adjust to different focal distances
transmits light and focuses it on the retina, it changes the shape of the eye lens to change the focal length of the lens to see distances
define emmetropia
refractive state in a healthy eye where there is perfect vision
define near response
constriction of pupil in response to looking at a near object
define convergence in the eye
the way your eyes move together to point inward when you look at nearby object
define accomodation in the eye
process in which the eyes see objects at different distances and can maintain clear images
define pigment epithelium
single layer of post mitosis cells that are a selective barrier and regulator of the photoreceptor layer
define photoreceptor cells
specialized cell found in the retina that cause visual photo transduction
define bipolar cells
interneurons in the retina that transfer visual information from photoreceptors (rods and cones) to amacrine
what is the differnce between rods and cones
rods: vision at low light (black and white)
cones: vision at high light (colors)
how does the distribution of rods and cones differ in the retina
there are more rods, located in the periphery of the eye and are good for detecting light in general.
cones are concentrated near the fovea, responsible for color vision and adapt easy to light
what are the functional consequences of the distribution of rods and cones in the retina
rods require less light to function, making night vision easier.
define rhodopsin
pigment in the retina, light sensitive inner lining of the back of the eye
define retinal
relating to the retina
which part of the photopigment is a protein and which part is a vitamin a derivative
the opsin is the protein, and the chromophore is the vitamin a derivative
where are the opsins located in the rod and cone
they are located in the photoreceptors of the retina
what happens to photopigment when the light hits
it transfers the energy to pigment
what are the three types of cones
blue, green, red
define bleaching of the eye
when the rod photopigment are exposed to light, they undergo bleaching.
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how do you get perception of differnt colors
cones
what causes red/green color blindness
it is a mutation from parents. all X chromosomes must carry the red/green color vision deficiency
where do the sensory information from rods and cones and ganglion cells travel in the brain
these go to the primary visual cortex in the back of the brain
where is the primary visual cortex
posterior of the occipital lobe
what is the role of the optic chiasm
formed when the optic nerves come together in order to allow for the crossing of fibers from the nasal retina to the optic tract on the other side
where does the info from the medial and lateral portions of the eye travel
the info from the right side goes to the left side (vice versa)
describe scoptic systems
associated with nighttime vision, vision under low light conditions
define photoptic systems
associated with daytime vision
does scoptic involve rods or cones
rods
does photoptic involve rods or cones
cones
what is visual acuity
sharpeness of vision
define myopia
nearsightedness, can see close but not far
define hyperopia
farsightedness, can see far but not close
how is hyperopia corrected
with convex lens
how is myopia corrects
concave lenses
what holds the retina in place
vitreous body
what happens to a detached retina
you lose vision due to no blood supply to the eye
what happens to your vision with detached retina
it goes away
what is macular degeneration
deterioration of the retina, loss of central vision
what is glaucoma
condition characterized by increased intraocular pressure and vision loss
