9.3 General Senses

tactile receptors

rubbing the skin in the area of an injury stimulates the __________________, which send action potentials along the sensory axons to the spinal cord

pacinian corpuscles

RELAY information concerning DEEP PRESSURE, VIBRATION, and POSITION (proprioception)

general anesthesia

a treatment where chemical anesthetics that affect the reticular activating system are administered

2nd type of pain sensation

diffuse, burning, or aching pain resulting from action potentials that are propagated more slowly

skin; others are associated with deeper structures, such as tendons, ligaments, and muscles

general senses are associating with the

cold receptors

respond to DECREASING temperatures, stop responding at temp.'s below 12 Celcius

warm receptors

respond to INCREASING temp.'s but stop responding at temp.'s above 47 Celcius.

touch receptors

- more complex than free nerve endings - many are enclosed by capsules - types: merkel disks, hair follicle receptors, messier corpuscles, Ruffini corpuscles, pacinian corpuscles

referred pain

- perceived to originate in a region of the body that is NOT the SOURCE of the PAIN STIMULUS - we sense this pain when deeper structures, such as internal organs, are damaged or inflamed - the brain cannot distinguish between the two sources of pain stimuli, and the painful sensation - clinically useful in diagnosing the actual cause of the painful stimulus

free nerve endings

- respond to painful stimuli, some to temperature, some to itch, and some to movement - these are relatively unspecialized neuronal branches similar to dendrites

gate control theory

- the action potentials "CLOSE THE GATE" and inhibit action potentials carried to the brain by the spinothalamic tract - may explain the physiological basis for several techniques that have been used to reduce the intensity of pain - explains why the intensity of pain is decreased by diverting a person's attention

visceral pain stimuli

are normally perceived as diffuse pain

Meissner corpuscles

are very SPECIFIC in localizing TACTILE SENSATIONS; involved in fine, discriminative touch

hair follicle receptors

associated with HAIRS, are involved in detecting LIGHT TOUCH

pain

characterized by a group of unpleasant perceptual and emotional experiences

1st type of pain sensation

localized, sharp, pricking, or cutting pain resulting from rapidly conducted action potentials

Ruffini corpuscles

play and important role in detecting CONTINUOUS PRESSURE in skin

deep or visceral pain

sensations are not highly localized because of the absence of tactile receptors in the deeper structures

superficial pain

sensations in the skin are highly localized as a result of the simultaneous stimulation of pain receptors and tactile receptors

proprioception

sense of movement and position of the body and limbs

light touch receptors

sensitive, but not very discriminative; AKA the point being touched CANNOT be precisely LOCATED

Merkel disks

small, superficial nerve endings involved in detecting LIGHT TOUCH and SUPERFICIAL PRESSURE

local anesthesia

suppresses action potentials from pain receptors in LOCAL areas of the body through the INJECTION of chemical anesthetics near a sensory receptor or nerve

general senses include

touch, pressure, pain, temperature, vibration, itch, and proprioception