Pupil fails to dilate by giving cocaine in :
Ans. is 'd' peripheral sympathetic paralysis In periphery cocaine blocks the uptake of Adrenaline and Noradrenaline in Adrenergic Nerve ending* resulting in higher concentration of sympathetic neurotransmitters (Sympathomimetic effect):The peripheral sympathomimetic action of cocaine produces following effect:1. Mydriasis2. Rise in B.P.3. Local vasoconstriction4. TachycardiaTherefore if the peripheral sympathetic system is paralysed it will lead to reverse of the above mentioned actions.
Central sympathetic paralysis
Central parasympathetic paralysis
Peripheral parasympathetic paralysis
Peripheral sympathetic paralysis.
Adrenergic System