September 9, 2023


If Anxiety Is In My Brain, Why Is My Heart Pounding? A Psychiatrist Explains The Neuroscience And Physiology Of Fear (Arash Javanbakht, 9/07/23, Discover)

If your brain decides that a fear response is justified in a particular situation, it activates a cascade of neuronal and hormonal pathways to prepare you for immediate action. Some of the fight-or-flight response - like heightened attention and threat detection - takes place in the brain. But the body is where most of the action happens.

Several pathways prepare different body systems for intense physical action. The motor cortex of the brain sends rapid signals to your muscles to prepare them for quick and forceful movements. These include muscles in the chest and stomach that help protect vital organs in those areas. That might contribute to a feeling of tightness in your chest and stomach in stressful conditions.

The sympathetic nervous system is the gas pedal that speeds up the systems involved in fight or flight. Sympathetic neurons are spread throughout the body and are especially dense in places like the heart, lungs and intestines. These neurons trigger the adrenal gland to release hormones like adrenaline that travel through the blood to reach those organs and increase the rate at which they undergo the fear response.

To assure sufficient blood supply to your muscles when they're in high demand, signals from the sympathetic nervous system increase the rate your heart beats and the force with which it contracts. You feel both increased heart rate and contraction force in your chest, which is why you may connect the feeling of intense emotions to your heart.

In your lungs, signals from the sympathetic nervous system dilate airways and often increase your breathing rate and depth. Sometimes this results in a feeling of shortness of breath.

As digestion is the last priority during a fight-or-flight situation, sympathetic activation slows down your gut and reduces blood flow to your stomach to save oxygen and nutrients for more vital organs like the heart and the brain. These changes to your gastrointestinal system can be perceived as the discomfort linked to fear and anxiety.

All bodily sensations, including those visceral feelings from your chest and stomach, are relayed back to the brain through the pathways via the spinal cord. Your already anxious and highly alert brain then processes these signals at both conscious and unconscious levels.

Posted by at September 9, 2023 12:00 AM