Ch 50 Flashcards
sensory receptors
-transduce stimulus energy and transmit signals to CNS
-involved converting energy into a change in membrane potential
-stimuli from diff. receptors travel as action potential along dedicated neural pathways
-brain distinguishes stimuli from diff. receptors based on areas of brain where action potential arrive
sensory pathways have 4 functions in common
-sensory reception
-transduction
-transmission
-integration
perception
brains contruction of stimuli
-sensory experience of the world
amplification
strengthening of stimulus energy of cells in sensory pathways
-brain may increase or decrease input based on what other sounds are around and what is more important
sensory adaptation
decrease responsiveness to continued stimulation
5 categories of sensory receptors
-mechanorecptors
-chemoreceptors
-electromagnetic receptors
-thermoreceptors
-pain receptors
mechanoreceptors
-sense physical deformation cause by stimuli (pressure, stretch, motion and sound)
-ex. knee jerk response (stretch receptor)
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chemoreceptors
-transmit info. about total solute [ ] of a solution
-detect changes in the chemical composition of the blood and send information to the brain to regulate cardiovascular and respiratory functions.
electromagnetic receptors
detect electromagnetic energy (light, electricity and magnetism)
-many animals move using the Earths magnetic field
theromoreceptor
-respond to temp.
-help regulate body temp. by signaling both surface and core temp/
-mammals have a # of kinds of thermorecptors ( each for a particular temp. range)
pain receptors
-nociceptors
-naked dendrites in epidermis
-respond to excess heat, pressure, or chemicals released from damaged or inflamed tissues
statocysts
organs that most invertebrates use to maintain equilibrium using mechanoreceptors
-help in sensing gravity and sound
statoliths
-mechanoreceptors that detect movement of granules in statocysts
hearing
-sound causes tympanic membrane to vibrate
-3 bones in middle ear transmit vibrations to oval widow on cochlea
-vibrtaions create pressure wave sin fluid in cochlea that travel to vestibular canal
-pressure waves in canal cause the basilar membrane to vibrate (bending hair cells)
-bending depolarizes membranes of mechanoreceptors and sends action potentials to brain via auditory nerve
-fluid waves dissipate when they strike round window of tympanic canal
equilibrium
several organs in inner ear detect body movement, position, and balance
-utricle and saccule
utricle and saccule
-contain granules called otoliths that allow us to perceive position relative to gravity or linear movement
3 semicircular canals
contain fluid
-detect angular movement in any direction
-responsible for balance
lateral line system
-most fishes and aquatic amphibians
-contains mechanoreceptors with hair cells that detect and respond to water movement
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photoreceptors
-light detectors
-cells that contain light absorbing pigment molecules
-simplest light detecting organs are in planarians (allows to move away from light and seek shaded locations) (Ocelli)
compound eyes
-consist of up to several thousand light detectors called ommatidia
-insects and crustaceans
-very effective at detecting movement
single lens eyes
-some jellies, polychaetes, spiders, and many mollucs
-iris changes diameter of the pupil to control how much light enters
-all vertebrates (eye detects light/color, the brain processes info and perceives image)