Question

How do sympathetic and parasympathetic nervous systems act differently on
(i) pupil of the eye, and (ii) urinary bladder?

Answer 1

The Action of sympathetic and parasympathetic nervous systems in:

1. Pupil of the eye:

Narrowing of the pupil happens when the round muscle, constrained by the parasympathetic sensory system (PSNS) contract. Dilation of the same happens when the smooth cells of the outspread muscle, constrained by the sensory system (SNS) contract.

2. Urinary bladder:

The muscles controlling Micturition are constrained by the autonomic and physical sensory systems. During the capacity stage the inward urethral sphincter stays tense and the detrusor muscle loose by sympathetic nervous system.

During Micturition, parasympathetic incitement causes the detrusor muscle to contract and the interior urethral sphincter to unwind. The outer urethral is under substantial control and is intentionally loose during Micturition.