synapse and sensory system

All receptors respond to a specific quality of a stimulus

A touch receptor will generate a constant rate of discharge of its axon for as long as the receptor is stimulated.

The frequency of a train of action potentials in an afferent fibre reflects the intensity of the stimulus given to its receptor

The first step in sensory transduction is the generation of an action potential

phasic receptors

nocioreceptors

exteroceptors

tonic receptors

generator potential

excitatory postsynaptic potential

action potential

stimulus potential

increases , increases

.increases,decreases

decreases, increases

decreases,decreases

oxygen lack

alkalosis

acidosis

prolonged activity of synapse

is due to increased Ca ++ concentration in postsynaptic neurons

is due to increased Ca ++ influx into presynaptic neurons

results from slow prolonged stimulation of synapse

causes fatigue of the synapse

visceral pain

deep pain

cutaneous hyperalgesia

colicky pain

anethesia is found at the level of lesion ipsilaterally

hyperthesia nay present above the level of lesion on the same side due to irritation of dorsal root

spastic paralysis and exaggerated muscle reflex is found contralaterally below level of lesion

all of the above are true

perception of pain is completely abolished

perception of touch is completely abolished

there is loss of tactile localization but two point discrimination is spared

there is loss of tactile localization as well as two point discrimination

brain tumor

lumbar puncture

constipation and alcohol

otitis media