Pain, Temp, Sleep, and Sensory Functions

sensory receptors

sensory nerve endings that respond to stimuli

afferent neurons

Nerve cells that carry impulses towards the CNS

phasic

rapidly adapting receptor

tonic

slowly adapting receptor

classes of sensory receptors

mechanoreceptors, thermoreceptors, photoreceptors, chemoreceptors, nociceptors

mechanoreceptors

respond to touch, pressure, vibration, and stretch

thermareceptors

respond to changes in temperature

photoreceptors

respond to light

chemoreceptors

respond to chemicals

nociceptors

pain receptors

lateral inhibition

The reduction of activity in one neuron by activity in neighboring neurons (can increase the brain's albility to localize a sensory input)

ascending neural pathway

Conducts sensory information upwards through a chain of 3 neurons connected by synapses

specific neural pathway

transmits sensory info on separate interneurons

interneuron

a neuron that carries nerve impulses from one neuron to another

nonspecific neural pathway

transmits sensory information on the same interneuron

Meissner's corpuscle

phasic mechanoreceptor to touch and pressure

merkel's corpuscle

tonic mechanoreceptor to touch and pressure

free neuron ending

tonic; includes nociceptors, itch receptors, thermoreceptors, and mechanoreceptors

pacinian corpuscle

phasic mechanoreceptor for vibrations and deep pressure

ruffini corpuscle

tonic mechanoreceptor for skin stretching

referred pain

sensation of pain experieced at sites besides the injured/diseased tissue

hyperalgesia

increased sensitivity to painful stimuli

pain pathway

pain stimulus, down afferent pain fiber, into CNS, released into synapse, thalamus, to somatosensory cortex

analgesia

a lessening of pain without loss of consciousness