Question

Which of the following is not an effect produced by parasympathetic stimulation?
(a) Dilation of the pupil
(b) Increased saliva production
(c) Increased stomach activity
(d) Construction of the bronchi

Answer 1

Hint: Parasympathetic nervous system is responsible for the body's rest and digestion. The sympathetic nervous system is responsible for the reflex adjustment of cardiovascular diseases. It activates when the body is in the rest position.

Complete solution:
The parasympathetic system is responsible for the stimulation of "rest-and-digest" or "feed and breed" activities as it is a part of the autonomic nervous system that controls the internal organs. The parasympathetic nervous system works when the body is at rest, especially after eating, including sexual arousal, salivation, lacrimation (tears), urination, digestion, and defecation.
The parasympathetic nervous system helps to decrease the respiration and heart rate when the body is at rest position. Stimulation of the parasympathetic nervous systems results in the constriction of pupils, a decrease in the heart rate and blood pressure.
1. The parasympathetic nervous system is one of the two divisions, the other being sympathetic, that together are called the autonomic nervous system, which is a division of another system called the peripheral nervous system.
2. The enteric nervous system is now thought to separate from the autonomic nervous system due to its independent reflex activity.
3. The autonomic nervous system is responsible for regulating the body's unconscious actions.
4. The action of the parasympathetic nervous system is described by the sympathetic nervous system as both are complementary to each other, which leads to the stimulation of activities associated with the fight-or-flight response.
5. When the parasympathetic nervous system is in an active state, it produces a calm and relaxed response in the body.

So, the correct option is 'Dilation of pupil'.

Note:
The parasympathetic nervous system is also known as craniosacral outflow as it is found between the sacral position of the spinal cord and brain.
The enteric nervous system is now thought to separate from the autonomic nervous system due to its independent reflex activity.