A QLD Government website
QSCIS
Queensland Spinal Cord Injuries Service

Sequence of events with dysreflexia

1
Noxious stimuli below injury

2
Message goes up and stimulates SNS causing vasoconstriction

3
Brain detects hypertension crisis through baroreceptors results in decreased HR (bradycardia)

4
Message goes down cord but only as far as injury level resulting in vasodilation above injury

A diagram showing the autonomic nervous system