Physiology and Pathophysiology
Core concepts
Understand autonomic balance, the HPA axis, inflammatory mediators, lymphatic return, and pain physiology including peripheral and central sensitization. Know how somatic dysfunction can alter afferent input, muscle tone, and local circulation, and how these changes feed back into symptoms. Respiratory mechanics, venous and lymphatic return, and tissue perfusion are frequent exam themes.
Pathophysiology links
Chronic pain involves sensitization: lowered thresholds, expanded receptive fields, and non-noxious stimuli becoming painful. This explains why a patient may report pain remote from the original restriction. Sympathetic overactivity can produce vasoconstriction, diaphoresis, and trophic changes. Inflammation follows a predictable sequence, and anything that improves drainage and perfusion supports resolution.
Traps
- Equating somatic dysfunction with a diagnosis; it is a finding, not a disease.
- Claiming OMT "cures" visceral disease rather than supporting function.
- Confusing sympathetic and parasympathetic effects on a given organ.
- Ignoring that central sensitization may limit response to purely mechanical treatment.
Rule of thumb
Trace any mechanism in three steps: input (afferent or mechanical), processing (autonomic or central), and output (perfusion, tone, symptoms).
Worked example
A patient with a chronic rib restriction reports vague arm aching without nerve tension signs. The explanation is sensitization with referred pain from sustained afferent bombardment, not a new radiculopathy - so the plan addresses the restriction and reassures rather than escalating imaging.