Anger is a complex emotion that involves several systems in the body. When someone experiences anger, there are both psychological and physiological changes that occur. Anger arises in the brain, but the feelings and physical sensations of anger are created by the interaction of the brain with different parts of the body. Scientific research has shown that anger engages multiple areas of the brain and leads to activation in the nervous system and endocrine (hormonal) system. Read on to learn more about the body systems involved in the anger response.
The Brain’s Role in Anger
The brain plays a central role in the generation and experience of anger. There are several parts of the brain involved:
Amygdala
The amygdala is an almond-shaped structure deep in the temporal lobes. It is part of the limbic system and is important for processing emotions, emotional memories, and responding to threats. The amygdala helps determine if a stimulus should elicit anger or fear. It also controls aggression and drives the physiological changes that occur with anger.
Hypothalamus
The hypothalamus is next to the amygdala and is also part of the limbic system. When you experience anger, the hypothalamus activates the sympathetic nervous system and triggers the release of stress hormones. This leads to increased heart rate, blood pressure, and energy production.
Prefrontal Cortex
The prefrontal cortex is the part of the brain responsible for complex cognitive behaviors like planning, decision-making, and moderating social behavior. When the prefrontal cortex is less engaged, people are more likely to act aggressively and have more difficulty controlling anger.
The Nervous System’s Response
The nervous system has an important role in creating the physical feelings of anger. Here’s how it responds:
Sympathetic Nervous System
The sympathetic nervous system controls the fight-or-flight response. When you feel threatened, the hypothalamus activates the sympathetic nervous system. This causes widespread effects including:
- Increased heart rate and blood pressure
- Redirecting blood flow to large muscle groups
- Increased breathing rate
- Increased sweating
These physical changes prepare you to take action and defend yourself aggressively if needed.
Facial Expressions
The facial muscles are controlled by the facial nerve, part of the peripheral nervous system. When you experience anger, the facial nerve causes facial muscles to contract, creating an angry facial expression with lowered brows, pressed lips, and flared nostrils.
The Endocrine System and Hormones
The endocrine system uses hormones to control mood, growth, metabolism, and tissue function. Several hormones play a role in anger:
Adrenaline
The adrenal glands release adrenaline (epinephrine) and noradrenaline (norepinephrine) when the sympathetic nervous system is activated. This leads to increased heart rate and blood pressure.
Cortisol
The adrenal glands also release cortisol during stress. Cortisol helps restore stability after the fight-or-flight response by suppressing the immune system, regulating blood sugar, and counteracting inflammation.
Testosterone
Testosterone is a male sex hormone released by the testes. Studies show that higher levels of testosterone are associated with aggression in both men and women.
The Cardiovascular System
The cardiovascular system has a vital role in the anger response:
Increased Heart Rate
Under stress, the sympathetic nervous system signals the heart to beat faster and pump more blood around the body. This provides extra energy and oxygen to the muscles, preparing for fight or flight.
Increased Blood Pressure
The surging adrenaline, cortisol, and norepinephrine increase blood pressure. Narrowing of blood vessels forces blood through the body with greater force and speed.
Increased Risk of Heart Attack and Stroke
Severe anger and risk of cardiovascular disease are closely linked. Frequent anger may damage arteries and heart muscle over time. The acute surge in blood pressure can trigger ruptures in arterial walls or blood clot formation – increasing the risk of heart attacks and strokes.
The Respiratory System
Here’s how breathing changes with anger:
- Blood chemistry changes lead to faster, deeper breathing.
- Breathing rate increases to facilitate the transportation of oxygen to the activated muscles.
- Exhaling forcefully helps expel air – similar to hyperventilating.
This rapid, forceful breathing is characteristic of the anger response.
The Musculoskeletal System
The muscles and skeleton ready the body for physical action:
- Muscle tension increases throughout the body.
- Shoulders hunch and square up to appear larger and more threatening.
- Fists and jaw may clench.
- Balance shifts as the body readies to lunge forward.
This muscular tension powers the potential for physical violence and aggression.
The Immune System
Anger and chronic stress weaken the immune system, making people more susceptible to illness and infection.
Specifically, anger and stress:
- Reduce numbers and activity of immune cells.
- Decrease antibodies.
- Lessen cancer cell destruction by immune cells.
- Increase susceptibility to colds and flu.
Conclusion
In summary, anger involves the activation of multiple systems throughout the body. The brain, especially the amygdala and hypothalamus, control and coordinate anger responses. Anger leads to sympathetic nervous system arousal, altering hormone levels, heart rate, breathing, and muscle tension. Though anger centers in the brain, its ripple effects impact the entire body. Learning to manage anger can lead to better emotional and physical health.