If someone breaks their neck and has complete paralysis of their arms and legs, why can their heart muscle still continue to contract? Explain.

Answer: Heart innervation

Explanation:

When the neck breaks, the spinal cord gets severely damaged. However, in some cases, the heart may continue to function. This is because the heart has a nerve (vagal innervation) that although split off from the brain, is not so close to the spinal cord but higher, and that way it is possible that the heart continues to function because it is not affected by physical trauma.

The answer is:

it isn't effected by most spinal cord injuries because it doesn't have the same source of innervation (supply)

Explanation:

Paralysis of the voluntary muscles below the neck due to this type of trauma would be a result of a severed spinal cord.

The heart gets innervation from the Vagus nerve (cranial nerve 10)

which doesn't come out of the spinal cord but rather the brain stem, which

is still protected in the skull where it branches off.

The diaphragm on the other hand receives innervation from

the Phrenic nerve, this originates at the cervical (the vertebra in your neck)