ch. 50 hearing Flashcards
stimuli =
energy
what does a sensory receptor convert stimulus energy into
a change in the membrane potential
4 basic functions of sensory pathways
- sensory reception
- transduction
- transmission
- perception
sensory reception
detection of stimuli by sensory receptors
what are sensory receptors
sensory cells or organs
neuronal receptors
receptor is the afferent neuron
non-neuronal receptors
receptor regulates afferent neuron
sensory transduction
conversion of stimulus energy into a change in the membrane potential of a sensory receptor
receptor potential
change in membrane potential
what are receptor potentials
graded potentials - magnitude varies with the strength of the stimulus
transmission
sensory information travels through the nervous system as action potentials
2 types of sensory receptors
- neuronal
- non-neuronal
what does the size of a receptor potential increase with
intensity of the stimulus
in sensory neurons that spontaneously generate action potentials at a low rate, a stimulus changes…
how often an action potential is produced
when can processing of sensory information occur
before, during, and after transmission of action potentials to the CNS
when does integration begin
as soon as the information is received
what does integration involve
processing of sensory information - brain receives sensory input and then forms response
perception
brain’s construction of stimuli
how does the brain distinguish stimuli from different receptors?
based on the path by which the action potentials arrive
amplification
strengthening of a sensory signal during transduction
sensory adaptation
decrease in responsiveness to continued stimulation
5 categories of sensory receptors
- mechanoreceptors
- chemoreceptors
- electromagnetic receptors
- thermoreceptors
- pain receptors
mechanoreceptors
sense physical deformation caused by forms of mechanical energy
what do mechanoreceptors typically consist of
ion channels linked to structures that end outside the cell
- like hair cells
what does the mammalian sense of touch rely on
mechanoreceptors that are dendrites of sensory neurons
what do mechanoreceptors open
mechanically gated channels
chemoreceptors
transmit information about the total solute concentration of a solution or respond to ind. kinds of molecules
what happens when a stimulus molecule binds to a chemoreceptor
chemoreceptor becomes more/less permeable to ions
what do the antennae of male silkworm moths have
very sensitive specific chemoreceptors
what do chemoreceptors open
chemically gated channels
electromagnetic receptors
detect electromagnetic energy (light, electricity, magnetism)
what type of receptors does the platypus have on its bill
electromagnetic rectors that detect electric field generated by prey
how do animals apparently migrate
using earth’s magnetic field to orient themselves
what do electromagnetic receptors open
electrically gated channels
thermoreceptors
detect heat and cold
what do certain snakes rely on thermoreceptors to do
detect infrared radiation emitted by warm prey
capsaicin
- in jalapeno and cayenne peppers
- receptors that respond to capsaicin respond to high temperatures also by opening a calcium channel
what do changes in temperature open
calcium channels
pain receptors/nociceptors
detect stimuli that reflect harmful conditions
what do pain receptors respond to
excess heat, pressure, or chemicals released from damaged/inflamed tissues
what do chemicals produced in an animal’s body sometimes enhance
perception of pain
how do most invertebrates maintain equilibrium
mechanoreceptors located in organs called statocysts
what do statocysts contain
mechanoreceptors that detect the movement of granules called statoliths
statoliths
provide information about the body position with respect to gravity
how do insects hear/respond to sound
- body hairs that vibrate in response to sound waves
- localized organs w/ tympanic membrane stretched over internal air chamber
how do crickets hear
- with legs
- detect changes in atmospheric pressure
- mechanically gated
where are sensory organs for hearing/equilibrium located in most terrestrial vertebrates
ear
pathway of hearing
- moving air reaches outer ear and vibrates tympanic membrane
- 3 bones of middle ear transmit vibrations to oval window
- pressure waves created in fluid of cochlea
- waves push down on cochlear duct and basilar membrane
- basilar membrane/attached hair cells vibrate up/down
- bending of hair cells depolarizes membranes of mechanoreceptors and sends action potentials to brain via auditory nerve
what do vibrating objects create
pressure waves in air
what does ear transduce pressure wave stimulus into
nerve impulses
what do we rely on to hear sounds
hair cells
hair cells
sensory cells with hairlike projections that detect motion
how do fluid waves dissipate
- when they strike round window at end of tympanic canal
- dampening of sound resets apparatus for next vibrations to arrive
what does the ear capture information about
volume and pitch
volume
amplitude of the sound wave
pitch
the frequency of the sound wave
how can the cochlea determine pitch
- basilar membrane not uniform along its length
- each region of basilar membrane is tuned to a particular vibration frequency
do lower or higher frequencies travel further
lower
what do several organs in the inner ear detect
body movement, position, and balance
what do the utricle and saccule contain
hair cells projecting into gelatinous material
what are embedded in the gel of the inner ear
granules called otoliths
otoliths
granules that allow us to perceive position relative to gravity or linear movement
semicircular canals
3 canals that contain fluid and can detect angular movement in any direction
where do fish have a pair of inner ears
near the brain
method of equilibrium maintenance in fish and aquatic amphibians
lateral line system along both sides of their body
lateral line system
contains mechanoreceptors with hair cells that detect and respond to water movement
