Sensory Physiology Flashcards
Define Sensation
- state of internal/external awareness
- stimulation
- receptor
- nerve impule to brane (afferent)
Define receptor and its functin
- dendrites
- generates potentials-take the sensory stimulus and turn it into an electrical signal (nerve impulse) that can travel along the neuron
Describe generator potential
-Since the receptor generates a change in the membrane potential, the receptor makes a generator potential - which is the term for its depolarization.
Define Projection
- (phantom pain-usually with chronic pain)
- senses are interpreted in brain and sent back to site of sensation (feel in our finger not brain)
Define adaptation
- unchanging stimulus causes message to stop sending
- except pain
Define afterimages
- Vision- responding to stimulates after it has eneded
- looking into a light, seeing it after eyes are closed
Define modality as they pertain to sensatins
-can discern one sensation from another
Classify receptors according to the location of the stimulus
- exteroceptors- in skin
- enteroceptors- visceroceptors (ate too much)
- proprioceptors-Joints- muscle sensation (for balance)
Classify receptors according to type of stimulus
- Mechoreceptors-physical change
- thermoreceptors- heat stimulus
- chemoreceptors- chemical change
- photoreceptors- eye light
- nociceptors- pain receptors (any other receptor overdone)
Describe 2 point discrimination and lateral inhibition
- the ability to tell 2 closely spaced points as distinct and separate points. The denser the receptors, the better your 2 point discrimination.
- Lateral inhibition is sharpening of the sensation. If receptors in the center are strongly stimulated and ones toward the periphery are weakly stimulated, the stronger pathway inhibits the weaker pathway.
Define receptor field
- area in skin whose stimulation result in nerve impulse
- lips sensitive(small field), thigh not as much (big field)
- 2 point discrimination, lateral inhibition
List the location, name and function of the receptors for tactile sensation
- Touch-Meissner’s or Touch corpuscles. They are located near the surface of the skin and respond to light touch.
- pressure-The Pacinian or Lamellated corpuscles are deeper and respond to pressure.
- vibration- Repeated stimulation of tactile receptors leads to vibration.
- thermoreceptive sensation-are free nerve endings (not encapsulated) and so are pain receptors.
- pain- over stimulate any receptor you can get a pain sensation (e.g. extreme cold).
Define referred pain
- we are less able to pinpoint in viscera
- left shoulder=heart attack
- because pathways run close together
Identify the proprioceptive receptors and indicate their functions
- kinesthetic sense (posture and balance)
- muscle spindles-inside skeletal muscle monitoring (causes patellar reflex) streach-
- Tendon organs-golgi tendon organs- contraction receptor
- These two receptors work together to provide your brain with “muscle sense” or proprioception.
