Vineet’s day begins with a cup of piping hot coffee. Caffeine is a stimulant present in coffee which increases the circulation of Adrenaline in the body. Vineet feels refreshed, alert and focussed.
Which part of the autonomic nervous system increases the secretion of Adrenaline?
Topic: Sympathetic nervous system
Answer
The SYMPATHETIC NERVOUS SYSTEM.
The autonomic nervous system has two divisions that act in OPPOSITION to each other: SYMPATHETIC — the "fight or flight" system. It stimulates the adrenal medulla to pour out ADRENALINE, raising the heart rate and breathing rate, dilating the pupils and the bronchi, and diverting blood to the muscles. PARASYMPATHETIC — the "rest and digest" system. It slows the heart, constricts the pupils and stimulates digestion.
THE ONE TEST that answers every question on this topic: does the change prepare the body for sudden action? If yes, it is sympathetic.
Adrenaline is called the EMERGENCY HORMONE for exactly this reason, and caffeine produces a mild version of the same state — which is why coffee makes the heart beat a little faster.