Physio Exam 3 Chapter 10 Part 1 Flashcards
Perceptions of the world are created by the brain from _____ sent from ______ receptors
AP and sensory receptors
Receptors transduce different forms of ______ to nerve impulses that are conducted to ____.
sensation, CNS
dendritic endings of sensory neurons: Pain/temperature-- Pressure/touch-- rods and cones---- modified epithelial cells--
free, encapsulated, sight, taste
grouped together according to the type of stimulus energy they transduce:
chemical stimuli in the environment or blood–
rods and cones–
temperature—
touch and pressure–
pain—-
body position—-
chemoreceptors, photoreceptors, thermoreceptors, mechanoreceptors, nociceptors, proprioceptors
Categorized according to the type of sensory information delivered to the brain:
Touch, pressure, temperature, pain—
Sight, hearing, equilibrium—
cutaneous receptors, special senses
Produce constant rate of firing as long as stimulus is applied, as in pain
tonic receptors
burst of activity but quickly reduce firing rate if stimulus is maintained
phasic receptor
requires least amount of energy to activate a receptor
adequate stimulus
regardless of how a sensory neuron is stimulated, only ______ sensory modality will be perceived, this allows the brain to perceive the stimulus accurately under normal conditions
one
In response to stimulus, sensory nerve endings produce a ______ change in membrane potential.
local graded
Potential changes are called ________ potential.
Analogous to EPSPs
receptor or generated
Generator potential increases with increased stimulus, then as stimulus continues, generator potential size diminishes, this is called the what response?
phasic response
generator potential proportional to intensity of stimulus is what kind of response?
Tonic response
cutaneous sensations: free nerve endings: Receptors for cold located in ____regions of dermis
Warm receptors are located _____in the dermis
More receptors respond to _____ than ______
upper, deeper, cold, warm
Hot temperature produces sensation of pain through a _______receptor? This allows ion channels for Ca and Na to diffuse into the neuron.
capsaicin
Nociceptors use ______or gultamate as NT? This allows Ca and _____ to enter though depolarizing channel, depolarizing the cell
substance P, Na
touch and pressure receptors, they adapt quickly
encapsulated
Ruffini endings and Merkel’s discs are responsible for what? are they quick adapting or slow adapting?
sensation of touch, slow
sensory information from proprioceptors and cutaneous receptors are carried by large _______ nerve fibers that synapse in the medulla
myelinated
(Lateral or Anterior Spinothalamic tracts)
heat, cold and pain—
Touch and pressure—
lateral, anterior
Area of skin whose stimulation results in changes in the firing rate of the neuron is called what?
receptor fields
Area of each receptor field varies _____ with the density of the receptors in the regions
inversely
back and legs have fewer sensory receptors thus they have a ______receptive field
larger
fingertips have a large number of cutaneous receptors so their receptive field is _______?
small
What is the minimum distance at which 2 points of touch can be perceived? this measures the distance between the receptive fields
Two-Point Touch Threshold
If distance between 2 points is less than minimum distance, only 1 point will be felt, this is an indication of……
tactile acuity
When a blunt object touches the skin, sensory neurons in the center areas are stimulated more than _____ fields.
neighboring
In lateral inhibition, without a clear, sharp boundary stimulation will gradually_____ from the point of greatest contact
diminish
Gustation is the sensation of…..
taste
each taste bud contains how many specialized epithelial cells?
50-100
Are taste cells neurons?
no, but they depolarize upon stimulation, if they reach a threshold they release a NT that stimulates sensory neurons
Each taste bud contains taste cells responsive to each of the different taste categories.
A given sensory neuron may be stimulated by_____ than ___taste cell in # of different taste buds.
more, 1
One sensory fiber may not transmit information ________ category of taste.
specific for 1
In regards to taste, the brain interprets the pattern of stimulation with the sense of smell; so that we perceive the ________
complex tastes
This taste involves Na passing through channels, activating specific receptors cells causing depolarization and a release of a NT
salty
This taste is involved with the presence of H+ passing through channels
sour
This taste is mediated by receptors coupled to G-protein gustducin
sweet and bitter
Olfactory apparatus consists of receptor cells, supporting cells and basal (stem) cells.
Basal cells generate new receptor cells every_____
1-2 months
In regards to olfaction, supporting cells contain _______ that oxidize hydrophobic volatile odorants.
enzymes
Neuronal glomerulus receives input from how many types of olfactory receptor(s)?
1 type
Bipolar sensory neurons located within olfactory epithelium are?
pseudostratified
Axon project directly up into olfactory bulb of ______. The olfactory bulb then projects to the olfactory cortex, hippocampus and amygdaloid nuclei, where it synapses with what order neuron?
cerebrum, 2nd order
Up to how many G proteins may be associated with a single receptor protein in regards to olfaction?
50
Odorant molecules bind to receptors and act through _____proteins to increase _____
G, cAMP
Dissociation of olfactory G-proteins releases G-subunits, thus doing what to the response?
amplifying it
Sensory structures of the vestibular apparatus is located within the membranous labyrinth. They are filled with what?
endolymph
Equilibrium is due to (with respect to gravity of course)…
vestibular apparatus
What are the otolith organs?
utricle and saccule
Utricle and saccule:
Provide information about _____acceleration
linear
Stereocilla and kinocilium are what type of receptors?
hair cell
When stereocilia bend ______kinocilium; membrane depolarizes, and releases NT that stimulates dendrites of VIII.
When bend _____from kinocilium, hyperpolarization occurs.
towards, away
In regards to the utricle and saccule, hair cells project into ______, where hair cells are embedded in gelatinous ________membrane
endolymph and otolithic
Utricle is more sensitive to _______acceleration and the saccule is more sensitive to ________acceleration
horizontal and vertical
Semicircular canals provide information about rotational acceleration and they project into how many different planes?
3
Each semicircular canal contains a semicircular duct, true or false?
true
In the semicircular canals hair cell processes are embedded in the…..
capula
Endolymph provides inertia so that the sensory processes will bend in direction ______ to the angular acceleration
opposite
Stimulation of hair cells in vestibular apparatus activates sensory neurons of cranial nerve…
VIII
Sensory fibers transmit impulses to cerebellum and _____ of medulla
vestibular nuclei
Movements of the head, neck and limbs are stimulated from neurons located where?
spinal cord
Sounds waves are characterized by ______ and ________?
Frequency (measured in hertz, with pitch related to frequency) and Intensity (directly related to amplitude of sound waves and measured in decibles)
External auditory meatus channels sound waves to the ______.
Increases sound wave intensity
tympanic membrane
Vibrations of the tympanic membrane are transmitted to the…
malleus, incus and stapes
This bone of the middle ear is attached to the oval window and vibrates in response to vibrations in the tympanic membrane
stapes
