Is heart rate controlled by the brain?

The heart rate is not directly controlled by the brain. Instead, it is controlled by the sinoatrial node (SA node), which is a small group of cells located in the right atrium of the heart. The SA node is responsible for generating the electrical impulses that cause the heart to contract. However, the brain can indirectly influence the heart rate through the autonomic nervous system, which is responsible for controlling many of the body's involuntary functions, such as breathing and digestion. The autonomic nervous system has two branches: the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system speeds up the heart rate, while the parasympathetic nervous system slows it down. When the body is at rest, the parasympathetic nervous system is dominant and the heart rate is slow. When the body is under stress, the sympathetic nervous system is dominant and the heart rate speeds up.