Exam 2: Senses Flashcards
(106 cards)
sensory receptors are specialized cells that…
- monitor external and internal conditions
- cover a specific area (sensory field)
- detect stimuli or changes
- send information to the CNS
all receptors function in _____ but no all are involved in _____
sensation
perception
perception
the conscious awareness of the sensation
ex: dorsal column tract
2 classifications of sensory receptors
general sense or special senses
general senses
-found in many places throughout the body
-simple in structure
T sensation, pressure, stretch receptor
special senses
- localized in one area
- complex in structure (eye - so many layers)
4 types of general sense receptors
- mechanoreceptors
- thermoreceptors
- nociceptors
- chemoreceptors
mechanoreceptors
respond to pressure, vibration, physical distortion
- monitors a cell or tissue fiber looks to see if compressed or stressed
- tactile receptor with CT around it, if pressure it gets compressed and sends signals
-hearing is special sense but uses mechanoreceptors - tympanic membrane and when hair cells distorted
thermoreceptors
respond to changes in T
-heat exchange - not giving the actual T but if it gets colder or hotter
nociceptors
respond to tissue damage as a pain sensation
- when cells destructed - tearing, chemical burn
- some fast, some slow
chemoreceptors
respond to dissolved chemicals
-taste, smell, pH
adaptive ability of receptors : fast adaptors
phasic
respond to change
only triggers when there is a change
adaptive ability of receptors: slow adaptors
tonic
send continual info to CNS
example of adaptive ability when putting a shirt on
phasic is stronger when putting shirt on and then tonic after it has been on you may not recognize you are wearing a shirt
3 types of mechanoreceptors
baroreceptors
proprioceptors
tactile receptors
baroreceptors
free nerve endings
found embedded in walls of distensible organs: digestive system, lungs, colon, bladder
- monitor changes in elastic tissue
baroreceptors - nerve endings - blood vessels
carotid and aortic sinus
- both chemo and baroreceptors
- monitors blood pressure
- vagus nerve will send this signal, some glossopharyngeal to see if P needs to inc or dec
baroreceptors - digestive system
locally - stretch receptors
when stomach emoties into SI it sends signals to get secretions from oancrease and gallbladder, does not happen without stretch receptor signaling
baroreceptors - lungs
need to have feedback to know it is working
stretch responders only respond when stretched- when you inhale you could see how long the signal is
baroreceptors and age - rigidity in walls of blood vessels - isolated systolic hypertension
high BP pushing blood into same vessel but it is resistant to expanding now
reduces recoil ability-diastolic P may dec
- not enough blood, fainting, fall risk
proprioceptors
-nerve endings wrapped around muscle or collagen fibers and then encapsulated by connective tissue (spindles and tendon organs)
tendon organs
tendons do not stretch, they have tension on them
gives idea both unconscious and conscious of what tension is on ligaments and tendons
what the muscle tone and tension is
-respond to patellar reflex
joint receptors
branched nerve endings encapsulated by connective tissue and embedded in joint capsule
where are proprioceptors located
embedded in muscle, tendons, ligaments, joint capsules