sensory receptors

sensory receptors

specialized cells or cell processes that alert CNS about conditions in/out of your body

general senses

temperature, pain, touch, pressure, vibration, proprioception; receptors distributed thru out the body

sensory pathways

begin at peripheral receptors, end w/i CNS

sensation

info carried by sensory pathway

perception

conscious awareness of a sensation

receptive field

area monitored by a single receptor cell. larger the receptor field, less able to localize stimulus

free nerve endings

tips of branching dendrites of sensory neurons. simplest receptors, respond to many different stimuli

nociceptors

pain receptors. free nerve endings w/ large receptive fields and broad sensitivity

two axon types carry pain info

myelinated type a fibers - fast, unmyelinated type c fibers - slow

thermoreceptors

temperature receptors. free nerve endings in dermis, skeletal muscles, liver, hypothalamus. cold receptors more numerus.

chemoreceptors

respond to water soluble and lipid soluble substances dissolved in body fluids

mechanoreceptors

respond to physical distortion of their plasma membranes. membranes have mechanically gated ion channels that open/close in response to stretching, compression

proprioceptors

monitor position of joints/muscles

baroreceptors

detect pressure changes in blood vessels and in digestive, respiratory, and urinary tracts

tactile receptors

provide sensations of touch, pressure, and vibration

fine touch and pressure receptors

give detailed info; very sensitive

crude touch and pressure receptors

give little info, poor localization

types of tactile receptors

free nerve endings, root hair plexuses, tactile discs, tactile corpuscles, lamellar corpuscles, bulbous corpuscles