Physiology - Sensory

Highly educated sensation

Mixed sensation

needs previous experience and intact sensory association cortex

intact in case of lesion in sensory cortex

Axosomatic

Axoaxonic

Axodendritic

Slowly adapting

carried by Ab aferent

Transmit through anterolateral system

Poorly localized sensation perceived at the thalamus

blocking the response of pain receptors to painful stimuli

Slowing down transmission of pain impulses through synapses in the pain Pathway

Inhibiting the response of the cerebral cortical somatic sensory area to pain Signals

Blocking Ca ++ channels in the central terminals of pain sensory fibers

being of shorter duration

being unable to summate spatially

Moving the membrane potential away from threshold

Depending upon opening of voltage Na + channels

Fast pain

Visceral pain

Deep pain

Cutaneous hyperalgesia

Colicky pain

indicates inability to localize the site of touch on the body surface

Results from lesions of the secondary somatic sensory area

Somatic Association area malfunction

Results from loss of crude touch sensation

Augmented realease of neurotransmitter from presynaptic terminal

Continued depolarization of presynaptic terminals

GABA receptors in presynaptic terminals

Opening of voltage-gated Ca ++ channels in presynaptic terminals

decreased synthesis of neurotransmitters

Inability to release neurotransmitters by exocytosis

Failure of action potentials to open voltage-gated Ca ++ channels in Presynaptic terminal

Imbalance in between rates of synthesis and release of neurotransmitters

increased heart rate

Depression

Withdrawal reflexes

Stoppage of impulse discharge from nociceptors in chronic painful conditions