How are involuntary actions controlled in our body, explain with a diagram?

 Involuntary actions are controlled by the autonomic nervous system, which is a network of nerves that regulates unconscious body processes such as heartbeat, blood flow, breathing and digestion. The autonomic system is part of the peripheral nervous system and is further divided into three branches: the sympathetic system, parasympathetic system and enteric nervous system .

The hindbrain and midbrain control involuntary actions like salivation and vomiting .The medulla of the hindbrain controls actions like blood pressure and salivation.