Lecture 19 Flashcards
Proprioception
Sense of body position- is based on the ability to perceive the position of the joints.-also includes vestibular sensations (sense of balance)
Kinesthesia
Perception of movements- does not include balance- substantially the same receptors as proprioception
Tactile Perception
Perception of objects that come into contact with the skin- exteroceptive sense: perception of the external world (such as vision or hearing)
Thermoalgesia
Temperature and pain- interoception: perception of the internal state of the body (such as hunger, thirst, or the urge to urinate)
A-Alpha
-Nerve
-Large (insulated)
-Proprioception (muscle sense- for example, refelxes)
A-Beta
-Nerve
-Medium (insulated)
-(non-painful touch, pressure)
A-Delta
-Nerve
-Small (insulated)
-Fast tissue damage (for example, pin pricks or intense heat)
C
-Nerve
-Small (uninsulated)
-Slow tissue damage (muscle or ligament tear), itch & burns
SA I (Merkel)
Texture perception + pattern/form perception
-Small receptive field –> more precise
-Slow adapting –> will continue to fire as long as there is something under it
-E.g. feeling shape of your key
SA II (Ruffini)
Finger Position
-Large receptive field
-Slow adapting
-E.g. shaping your fingers to grasp key
FA I (Meissner)
Low-frequency vibration detection
Stable grasp
-Small receptive field
-Fast adapting
-Holding grip onto object
-E.g. grip strength to insert key into lock
FA II (Pacini)
High-frequency vibration detection
Fine texture perception
-Large receptive field
-Fast adapting
-E.g. tells you when key as reached the end of the keyhole
Dermatoma
All touch fibers eventually group together into a nerve that enters the spinal cord between each spinal disc. Each area of the skin innervated by a specific nerve is called a…
Two-Point Discrimination Threshold
The threshold distance between two cutaneous stimuli at which individuals misperceive the separate stimuli as one
Pain
An unpleasant sensory and emotional experience associated with, or ressembling that associated with, actual or potential tissue damage
Nociception
The neural process of encoding nociceptive stimuli
Nociceptive Stimulus
An actual or potentially tissue-damaging event transduced and encoded by nociceptors
Pain Intensity Theory
-No specific neural system
-High intensity stimulus = perceive pain
Pain Specifity Theory
-Specific neuron perceives pain
Nociceptors
Sensory receptors that transmit information about harmful stimulation that may cause damage to the skin or lead to a risk of damage
-A-Delta fibers (sharp, rapid pain) + C fibers (throbbing sensation)
Local Anesthetics
Inhibiting excitation of nerve endings or by blocking conduction in peripheral nerves. This is achieved by anesthetics reversibly binding to and inactivating sodium channels.
