sensory receptors and sensory transduction Flashcards
sensory receptors
cells that detect stimuli and produce receptor potentials
interoceptors
monitoring within the body
proprioceptors
respond to changes in position of the body or its part
-helps with coordination
-we need to know where everything is
exteroceptors
respond to stimuli that arise outside the body
mechanoreceptors
mechanical displacement
-inner hair cells are this type
thermoreceptors
temperature change
nociceptors
pain, tissue damage
chemoreceptors
chemicals
photoreceptors
light
adequate stimulus
the type of stimulus to which a receptor is most sensitive
-multiple receptor types can react to a single stimulus
receptive field
area in the periphery where application of an adequate stimulus will cause a receptor to respond
cutaneous receptors
encapsulated (with layers or a think capsule) and non-encapsulated (free nerve endings or accessories structures) receptors
what are the 3 encapsulated receptors
pacinian corpsucle, meissner corpuslce, ruffini ending
what are the 3 non-encapsulated receptors
hair receptors, merkel endings, free nerve endings
pacinian corpsucle
good for acceleration
-looks like a little onion in image
meissner corpuslce
touch velocity
-bulge on it that will be deformed when skin is moved or compressed
ruffini ending
detects the skin stretching and warmth
hair receptors
hair being moved
-near bottom of the hair follicle
-will move or stretch as hair follicle is moved
merkel endings
as the skin moves, these endings will be altered
-within the skin
free nerve endings
picking up pain
-no capsule or bulge around it
main job of receptors in muscles and joints
measuring proprioception
muscle spindles
detects muscle length
-encapsulated
-within muscles
golgi tendon organ (GTO)
detect muscle tension
-encapsulated
-attaches to tendons
joint receptors
responds to joint positions and movement
-within the joints
-free nerve endings and other similar to those within the skin
visceral receptors
internal organs with a variety of receptors
-mostly free nerve endings
sensory transduction
converting stimulus into energy spikes (AP)
-receptors in PNS need to pick up stimuli
sensory receptor
cells that detect types of stimuli and generate receptor potentials
potential
electrical difference/change/firing
if a _______ is reached, then an action potential will be generated to travel along the axon
threshold of change
if opposite charges are physically separated…
energy is expended and work is performed to keep separate
-separated charge is potential electrical energy
resting potential
non uniform distribution of an differential permeability to sodium and potassium and impermeable anions
-about -70 mV in neurons when compared to the outside
ions of cellular millieu
potassium, sodium, chloride, calcium and other anions
receptor potential
stimulation of cells
-ion channels open (mechanically gated)
-cutaneous receptors can be deformed by pressure of touch or IHC sterocilia sheared
sequence of events at receptor with stimulation
graded potential changes local membrane potential, opening during pressure which lets sodium rush in that are, depolarization occurs with the sodium influx, sensory information gets encoded, which causes an action potential
what is the order of potentials
resting, receptor, AP, synapse, EPSP
how does the action potential travel along the axon
travel along neuron, communication across synapse, carried to a destination fro action or processing, and receptor returns to resting potential after this occurs
what gets encoded
type of stimulus, location, strength/intensity, duration, frequency and rate
resting potential is _________ modulated
amplitude
action potential is __________ modulated
frequency
how is they type of stimulus encoded
each receptor has a modality of what it is picking up and its a line labeled pathway to an area of the brain
-picking up the type of receptor for what occured
how is location encoded
because of mapping
