concept 50.1: sensory receptors transduce stimulus energy and transmit signals to the central nervous system

what does stimuli represent

forms of energy

what does a sensory receptor do

converts stimulus energy into a change in the membrane potential

what is the corpus collosum

a large bundle of axons/ nerves and allows the left and right side of the brain to interact

what are the four basic functions of sensory pathways

sensory reception

transduction

transmission

perception

what is the first step in a sensory pathway

sensory reception, or the detection of stimuli by sensory receptors

sensory receptors

sensory cells or organs that interact with stimuli in and outside of the body

what occurs in sensory transduction

the stimulus energy is converted to a change in membrane potential of a membrane receptor

receptor potential

the change in membrane potential that occurs following a sensory transduction, a graded potential

what does it mean to be a graded potential

the magnitude of the potential varies on the strength of the stimulus

that happens as the intensity of the stimulus increases

the size of the receptor potential increases

what are included with sensory receptors

some sensory receptors can be specialized neurons and others can be specialized cells that regulate neurons- These are NOT NEURONS

does the magnitude or frequency of action potentials vary

the magnitude does not vary but the frequency of the action potentials does based on stimulus intensity

what is the result of a larger receptor potential if the receptor is a neuron

there will be more frequent action potentials

what is the result of a larger receptor potential if the receptor is not a neuron

this will cause more neurotransmitters to be released from that specialized sensory cell

afferent/sensory neurons

approach CNS

efferent/motor neurons

exit the CNS

perception

brains construction of stimuli

how does stimuli from different sensory receptors travel

they travel as action potentials along dedicated neural pathways, and the brain distinguishes stimuli from different receptors based on the path by which the action potentials arrives

what do mechanoreceptors do

sense physical deformation caused by forms of mechanical energy- stimuli such as pressure, stretch, motion and sound

what do chemoreceptors do

transmit information about the total solute concentration of a solution, used for smell and taste

what do electromagnetic receptors do

detect electromagnetic energy such as light, electricity and magnetism

photoreceptors

electromagnetic receptors in our eyes that allow us to perceive light

what do thermoreceptors do

respond to heat or cold, help regulate body temperature by signaling both surface and body core temperature

capsaicin

in jalapeno and cayenne peppers that thermoreceptors respond to as a high temperature

pain receptors or nociceptors

detect stimuli that reflect harmful condition's and respond to extreme pressure, temperature or chemicals released from damaged or inflamed tissues

why do we not only use 10% of our brain

because a majority of out brain is doing things that we are not conscious about