So we will conclude this lecture by discussing two disorders that affect the blood vessels
due to a malfunction of the autonomic nervous system.
The first of those disorders is autonomic dysreflexia.
In this life-threatening disorder, there is a sudden onset of excessively high blood pressure
due to an injury to the spinal cord at T6 or above.
A second disorder which is less life-threatening
and can be controlled just with mitigating circumstances is Raynaud phenomenon,
also known as Raynaud's syndrome.
In this syndrome, spasms or vasoconstriction of the arteries
lead to a decrease in the blood flow to the extremities such as the fingers and the toes,
and sometimes even the lips.
This decrease in blood flow causes the fingers and toes to feel numb or very cold.
This is usually triggered by either a change in temperature or extreme stress.