system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:If you are paralyzed from the neck down, why do your organs still work?

shouldn't your heart, lungs, intestines etc... stop receiving signals from your brain?
gpt
Even though your lungs are organs the way they work is a little different as they require help. The process of breathing uses skeletal muscle (The diaphragm) and thus has no "Automatic" control. There are 2 nerves arise from up in the neck at C3-5 ( C3, C4 and C5 keep the diaphragm alive), there is one on either side called the phrenic nerves. If lets say a tumor on one side compresses the nerve this is reflected in one side of the diaphragm becoming paralysed. 

Someone mentioned the heart. The nerves that supply the heart are NOT all directly from the spinal cord they come partially from spinal cord but also from two cords that run parallel called the sympathetic trunk. The heart is a weird one. If you removed all the nerves from the heart it would beat at around 100 bpm. So it takes nerves (these ones from the spinal cord) to slow it down. This is called a parasympathetic tone and comes from the longest nerve in our body called the wonderer (Vagus X).

Intestines are really weird. They are tricky to learn about and even harder to explain. Basically remember i mentioned the sympathetic trunk well that and the top and bottom of the spinal cord (Called the parasympathetic outflow) both help regulate a third nerve system called the enteric nervous system (ENS). The ENS is the one that regulates the movements of the intestines along with a few hormones e.g. motalin

Interesting bonus points: Stomach acid can be released via a few mechanisms but one way is by the same nerve that slows the heart. Years ago when people had stomach ulcers one of the treatments used to be to remove the nervous supply to the stomach and thus reduce acid secretions.

As for the Kidneys, Liver and Spleen the nervous supply is primarily to do with blood flow rather than function.