Lecture 7 Flashcards
6 categories of human sensory receptors
chemosensor
mechanoreceptor
noiceptor
photoreceptor
thermoreceptor
phono-receptors
variation in human sensory capacity is due to …
genetics
maturation
circadian rhythm
experience / training
fatigue
injury / disease
etc
what is the first step in the process of sensation
reception - ability of receptor to absorb energy of a stimulus
what is the second step in the process of sensation
transduction - conversion of stimulus energy into a membrane potential, transfers it into a certain action potential
what is the third step in the process of sensation
Gets information out there into the body so it can be used APs->CNS
what is the fourth step in the process of sensation
Integration: our brains trying to process this information depends on the frequency of the signals coming to the brain
what is sensation coded as
frequency of neurons firing
a decrease in responsiveness by receptors due to continual stimulation usually means what has occurred
accomodation of a stimulus
a uniformly maintained stimulus of constant intensity is perceived as what over time (and an example)
perceived as progressively weaker with time
example = when you put your clothes on in the morning you can feel them, but this becomes dull
a variable intensity stimulus of shorter durations is perceived as what over time
perceived as progressively stronger over time
what is meant by sensation
detect the information
what is perception
understand it, to make sense of it
what are the two roles of the primary somatosensory cortex and how is it organised
integration of sensory information
provides meaning to our perceptions topographically
topographically organised
what occurs if there are lesions to the primary somatosensory cortex (3)
defective localisation
loss of proprioception
tactile agnosia
what is tactile agnosia
trouble to identify an object by touch alone
why cant we tickle ourselves
Our brain anticipates whats coming to us and turns down sensitivity threshold
what are the three main types of receptors
interoceptors
proprioceptors
exteroceptors
what are interoceptors
states our internal organs (not so relevant for motor control)
what are proprioceptors
information about our own movements
what are examples of proprioceptors
muscle receptors
joint receptors
cutaneous receptors
vestibular system
what are exteroceptors
information about the movement of objects in the environment
Vision and audition
what is proprioception
sensation and perception of the position and movement of limbs, head and trunk
what are muscle spindles parallel to
spindles are parallel to muscle fibres
when will a muscle spindle fire
when the muscle is stretched
what do muscle spindles send
signals via motor neurons to spine and up (afferent)
what are type II muscle spindles more sensitive to
length
what are type Ia muscle spindles more sensitive to
velocity
when will golgi tendon organs fire
when muscle contracts
where are golgi tendon organs found
within tendons
what do golgi tendon organs give feedback of
muscle tension
what are joint receptors
sensory endings in the joint
what do joint receptors tell us
provide information of the joint angle
what are cutaneous receptors
receptors in the skin
what do mechanoreceptors measure
deformation of skin
what is signals balance in the vestibular system
information about the position and movement of head
what is the location of the vestibular system
middle inner ear deep within the temporal bone
what are sensors of the vestibular system triggered by
linear and angular acceleration of the head
