If someone is paralyzed from the neck down, why does their heart/lungs/ect still work?
In: Biology
The beating of the heart is controlled by nerves in the heart itself, originating from the sinoatrial node. This is why a heart transplant isn’t a problem. Indeed a heart can continue beating outside the body for hours, as long as it’s provided with a supply of oxygenated blood.
Breathing reflex is controlled by the brain stem via the spinal cord. Respiratory paralysis is a concern in a serious head or neck injury.
People who are quadriplegic generally need an artificial ventilator.
The heart can be *influenced* by the vagus nerve,(parasympathetic nervous system) and the cardiac nerve which originates from the sympathetic ganglia. Both of these are largely autonomous and aren’t necessarily affected by a neck injury.
The vagus nerve works to slow the heartbeat in certain situations by producing acetylcholine. The cardiac nerve works to increase heart rate and increases force of contraction. But again these don’t produce the heartbeat itself.
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