Ch 50 A Flashcards
Stimuli =
energy
When may a motor response be generated?
When a stimulus is received and processed by the nervous system
What are the 4 basic function of the sensory pathway?
1) Sensory reception
2) Transduction
3) Transmission
4) Perception
What is Sensory reception?
Detecting of stimulus by sensory receptors
What is Transduction?
Conversion of stimulus energy into a change in membrane potential of a sensory receptor
What is Transmission?
Sensory info travels through the nervous system as action potentials
Where does a sensory pathway begin?
Sensory reception
Detection of stimuli by sensory receptors
What are Sensory receptors?
Sensory cells or organs
What are the 2 types of sensory receptions?
1) neuronal: receptor is the afferent neuron
2) non-neuronal: receptor regulates afferent neuron
What is transduction?
Conversion of stimulus into a change in membrane potential
Receptor potentials are what kind of potential?
why?
Graded potentials
Magnitude varies with strength of stimulus
What is transmission?
Sensory info travels through the nervous system as action potentials
How does sensory information travel through nervous system?
As action potential
What changes how often action potentials are produced
Stimulus
What is integration?
When our brain combines info from different sources
When can the processing of sensory information occur?
Before, during, and after transmission of action potentials to the CNS
When does integration begin?
As soon as information is received
What is perception?
The brain’s construction of stimuli
How the brain interprets incoming info
How does brain distinguish stimuli from different receptors ?
Based on the path by which the action potential arrive
What is sensory adaptation?
The decrease in responsiveness to continued stimulation
What is amplification?
the strenthening of a sensory signal during transduction
5 sensory receptors
1) Mechanoreceptors
2) Chemoreceptors
3) Electromagnetic receptors
4) Thermoreceptors
5) Pain receptors
How do Mechanoreceptors work? (2)
1) Sense physical deformation caused by mechanical energy
2) Uses ion channels linked to structures outside the cell
What does mammalian sense of touch relies on?
Mechanoreceptors that are dendrites of sensory neurons
What are the 2 touch organ receptors?
1) free nerve ending
2) meissner corpuscle
What do mechanoreceptors open?
mechanically gated channels
How do Chemoreceptors work? (2)
1) Some transmit info about the total solute concentration of a solution (ex. blood)
2) Others respond to individual kinds of molecules (ex. taste cells, olfactory rececption cells)
What happens when a stimulus molecule binds to a chemoreceptor?
Chemoreceptor becomes more or less permeable to ions
What do chemoreceptors open?
chemically gated channels
How do Electromagnetic receptors work?
Detect electromagnetic energy such as light, electricity, magnetism
What do electromagnetic receptors open?
electrically gated channels
How do Thermoreceptors work?
1) Detect heat and cold
2) changes in temp open Ca+ channels
What is special about jalepeno and cayenne peppers regarding thermoreceptors?
Receptors respond to capsaicin by opening a calcium channel
What is a special trait about mammalian thermoreceptors?
they have thermoreceptors for each particular temperature range
How do Pain receptors work?
AKA Nociceptors- detect stimuli that reflect harmful conditions
What do pain receptors respond to
Excess heat, pressure, or chemicals from damaged or inflamed tissues
Invertebrates maintain equilibrium using mechanoreceptors located in organs called
statocysts
Statocysts detect movements of granules called
statoliths
What do statoliths do?
Provide info about the body position with respect to gravity
What kind of channels detect changes in atmospheric pressure
Mechanically gated
How do we hear
The ear transduces pressure waves (stimulus) into nerve impulses
What do we use to hear inside the ear?
Hair cells
Hearing process
1) vibrating objects create pressure waves in air
2) Air reaches the outer ear and vibrates the tympanic membrane
3) three bones of the middle ear transmit the vibrations to the oval window
4) The stapes vibrates against the oval window which creates pressure waves in the fluid inside the cochlea
5) pressure waves push down the cochlear duct and basilar membrane causing hair cells to vibrate up and down
6) depolarizes membranes of mechanoreceptors and sends action potential via the auditory nerve
When do fluid waves dissipate?
When they strike the round window at the end of the tympanic canal
What resets the apparatus for the next vibrations
The damping of sound at the round window
What is volume?
the amplitude of the sound wave
What is pitch?
the frequency of the sound wave
What is special about the basilar membrane and frequency?
each region is tuned for a particular vibration frequency
what organs contain hair cells projecting into a gelatinous material?
Utricle and Saccule
What helps us perceive position relative to gravity or linear movement
Otoliths
What contains fluid and can detect angular movement in any direction
Semicircular canals (3)
What do fish have for hearing?
Pair of inner ears near the brain
Lateral line system
Contains mechanorecptors with hair cells that detect and respond to water movement
