Hot water bottle relieves the pain of abdominal spasm by?
Stimulation of adrenergic fibers
Stimulation of cholinergic fibers
Inhibition of cold receptors
Inhibition of heat receptors
- Here the probable answer will be “A”.
- According to the Gate control theory, painful impulses must first pass through a ‘gate’ in the spinal cord before they can be interpreted as ‘pain’ in the brain.
- Non-painful stimuli such as touch and temperature activate other (larger) nerve fibers that block / close the gate to the painful stimuli and thereby inhibit the perception of pain.
- Visceral pain from the gastrointestinal tract is largely mediated by pain relaying ‘C’ fibers that run almost exclusively in the sympathetic (adrenergic) system.
- These incoming pain signals from gastrointestinal spasm can be inhibited/blocked from reaching the brain (perception of pain) by closing ‘the gate’ at the level of the spinal cord.
- Heat impulses from hot water bottles are transmitted through larger A fibers and C fibers and these may close/block ‘the gate’ to painful impulses transmitted through C fibers from the gastrointestinal viscera.
- Relief of pain with a hot water bottle involves modulation of sympathetic (adrenergic) pathways through stimulation of the ‘A’ and ‘C’ fibers thereby blocking the pain sensation carried by sympathetic (adrenergic) small ‘C’ fibers from gastrointestinal viscera.
- Thus, sympathetic (adrenergic) fibers are blocked (not stimulated) and therefore no option is correct.
- However, among the given options only adrenergic fibers are related to visceral abdominal pain.
- If the question is repeated as such, you can go ahead with option “A”.