Cardiovascular Regulation With an upper (thoracic vertebral level 6 and higher)
ID: 3515141 • Letter: C
Question
Cardiovascular Regulation
With an upper (thoracic vertebral level 6 and higher) spinal cord injury, it is possible for patients to develop autonomic dysreflexia. In this life-threatening syndrome, a strong sensory input (commonly full bladder) causes a surge of sympathetic response.
A- What would that do to the blood pressure and heart rate?
B- What would the baroreflex response be and what path would it take to accomplish its effect?
With the spinal injury, signals from the brain’s vascular control center can’t get through to the sympathetic system.
C- With the body’s attempt to compensate, what would happen with the blood pressure and heart rate?
If left untreated, autonomic dysreflexia can result in cerebral hemorrhage, pulmonary edema, myocardial infarction, and renal insufficiency -among other things.
D- What causes the damage if it continues?
Explanation / Answer
A).Normal systolic blood pressure for an individual with spinal cord injury above T6 is 90- 110mm Hg; blood pressure of 20-40 mm Hg above reference range for such patients may be a sign of autonomic dysreflexia.
Reflex spinal mechanism from noxious stimulus leading to sympathetic over activity below the lesion.
Imbalanced reflex sympathetic discharge leads to life threatening hypertension. There is an increased vascular alpha adrenoceptor responsiveness, and peripheral afferent stimulation in individual induces a marked noradrenaline spillover below the level of spinal lesion, these neurophysiological changes possibly contribute to the development of autonomic dysreflexia.
A slow pulse lower than 60 beats per minute, reflex bradycardia.N we've receptors in the heart and blood vessels detect this rise in bp and sends a message to the brain.The brain then sends a message to the heart , causing the heartbeat to slow down and the blood vessels above the level of injury to dilate.