What part of the brain triggers the release of adrenaline?

In this article we will answer the question ‘’What part of the brain that triggers the release of adrenaline?’’ We will also talk about what happens to the body when adrenaline is released, how it controls it, things that could happen and what the adrenaline hormone is.

What part of the brain triggers the release of adrenaline?

The hypothalamus is the part of the brain that triggers the release of adrenaline.The hypothalamus stimulates the sympathetic nervous system by transmitting signals across the autonomic nerves to the adrenal glands after the amygdala sends out a fear signal. By pumping the hormone epinephrine into the bloodstream, these glands respond.

Adrenaline releases happen when the adrenal glands secrete an excessive amount of adrenaline into the body. These shocks usually happen in response to a spike in a great deal of stress or anxiety.

Epinephrine is a hormonal substance from the group of sympathomimetic amines (which stimulate the sympathetic nervous system). More specifically, adrenaline is a catecholamine.It is synthesized in the adrenal gland and when released into the blood it exerts its effect practically throughout the body.

Its synthesis and release are not controlled by the will. The organism does it autonomously. However, there are specific situations and stimuli that cause a sudden release. This is what we call “adrenaline rush.” 

When adrenaline surges occur, their effects appear with great intensity. These effects are usually unpleasant for those who suffer them and are similar to those of a panic attack.

What effects does adrenaline have on our body?

Epinephrine is present in the brain as an element of the metabolic chain of neurotransmitters. Neurotransmitters are substances that are stored in neurons and are removed from one to another to transmit stimuli. 

Adrenaline could act itself as a neurotransmitter and the truth is that the mechanisms by which adrenaline would be released in the nervous system are not yet well understood. Nor if they would be related to peripheral liberation.

Normally, the effects of adrenaline in our body are the following:

  1. It increases the rate of contraction of the heart and causes tachycardia.
  2. It has a dual effect on blood vessels. It first makes the skin pale and then makes it red. This occurs by dilating the blood vessels.
  3. Initially, it slows down breathing. Then, its effect is stimulating, increasing the respiratory rate.
  4. Dilate the pupils.
  5. It causes a sudden alteration of the metabolism of fats and carbohydrates. Circulating glucose in the blood increases, thereby increasing available energy.
  6. It relaxes the muscle fiber in the walls of the digestive tract, thereby reducing digestive activity.

Sudden adrenaline releases are accompanied by anguish, irritability, tension, and restlessness. This effect on the central nervous system appears to be secondary to peripheral cardiovascular effects. This is so because the body’s adrenaline does not cross the blood-brain barrier. That is, it does not reach the brain.

Adrenaline Rushes Don’t Happen

Adrenaline discharges occur in situations of tension and fear that either occurs abruptly or as in the case of stress, have a continuous nature. 

The basic phenomenon is the excitation of the sympathetic system, with an excessive release of adrenaline, which puts the organism in an emergency situation called “fight or flight”.

Along with adrenaline, the adrenal gland also releases corticosteroids and other catecholamines, such as norepinephrine. All of this sets in motion the body’s defensive and reserve system. In this way, it prepares you for any eventuality.

Thus, blood pressure rises, digestive activity decreases, and sweating and muscle tone increase. At first, it is useful to control movements; But if you go over a certain limit, you can alter coordination.

These adrenaline rushes occur associated with a feeling of threat. This threat can be both real and imagined. It can happen due to fright, the unexpected appearance of someone or simply a question from a teacher in class (not forgetting about stress).

Adrenaline Rushes Are Not Dangerous

Adrenaline releases are not a serious or abnormal situation, although they can scare those who suffer them. In the long run, if it is perpetuated, it does exert harmful effects, weakening the body and keeping it in a constant state of fatigue.

If you are prone to them, through the use of relaxation techniques or changes in your lifestyle you may be able to decrease the frequency and intensity of adrenaline surges. 

Physiological deactivation techniques, such as diaphragmatic breathing or progressive muscle relaxation training, usually give very good results

Effects of adrenaline in the body

The release of adrenaline has a positive effect on the body as long as it is not given in excess, which is why so many people deliberately seek it in their sports activities. The main actions that epinephrine produces on the body are the following:

Increase heart rate. This causes more oxygen to reach the muscles, making them better able to work and exert themselves more. 

Adrenaline increases the heart rate since, in a stressful situation, it is important to ensure that all the organs and tissues of the body receive enough blood, especially the muscles. 

When we are under its effects, this increase in heart rate is perfectly recognizable. Our hearts are racing.

Breaks down glycogen

It is the energy stored for when the body needs an extra effort that lasts more than a minute. When we are in a dangerous situation, adrenaline causes a dilation of the pupils to sharpen the sense of sight. 

This is a very primitive mechanism, as animals need this increased range of vision to escape predators. Similarly, this makes it easier for us to see in dark environments.

Increases the capacity of the respiratory system by instantly relaxing the bronchial tubes, allowing more air to enter

When we are in a stressful situation, breathing becomes uncontrolled. We inhale and expire at a much higher rate than normal. This is also a matter of adrenaline, which causes the lungs to work much faster to oxygenate the body to the maximum.

The breathing rate quickens

 In this way, the blood mobilizes more oxygen and releases more carbon dioxide.

Dilation of the pupils

It causes a greater reception of light, which momentarily enhances the visual capacity and helps to perceive the stimuli of the environment more quickly.

Expands blood vessels directly linked to vital organs to improve their performance in these situations.

At the same time, it widens the peripheral vessels that are thinner to prevent them from breaking. This causes blood pressure to go up.

Facilitates the movement of information between nerve cells as it is a neurotransmitter

It causes sensations derived from chemical reactions in the body similar to those of an orgasm

Helps fight depression, as the release of adrenaline stimulates the creation of dopamine that increases mental well-being. It generates states of euphoria.

Inhibit non-essential functions

When we are in a stressful situation, the body has to forget about all those bodily functions that are not going to contribute to our survival or that are even going to be a hindrance, since they involve allocating energy to something that, when there is a danger, is not essential. 

Therefore, adrenaline causes non-essential functions to be inhibited, such as digestion.

Increase energy

Adrenaline stimulates the mobilization of glycogen, that is, it encourages the body to “take hold” of the energy reserves in muscles and other organs of the body. Adrenaline allows this energy stored in the form of glycogen to be converted into glucose, which is already assimilated by cells and increases the energy we have.

In other words, adrenaline gives muscles and other organs a boost of energy that was reserved for emergency situations. In this way, the body ensures that we will always have the energy to flee (or defend ourselves) from the threat.

Sharpen the senses

When we are high on adrenaline, all our senses are heightened. This is thanks to the action of adrenaline, which directly influences the functioning of the nervous system so that the messages from the sensory organs (sight, touch, hearing, taste and smell) reach the brain in a more effective way.

Increase sweat production

In order to regulate body temperature and so that we can respond more efficiently to danger, adrenaline stimulates the production of sweat. In this way, we prevent our body temperature from rising too high to make our response difficult.

Stimulate memory

Recently it has been observed that adrenaline could play an important role in the central nervous system, in the sense that it stimulates the consolidation of long-term memories. 

This would explain that the stressful and dangerous situations that we have experienced never fall into oblivion, which could also be a survival mechanism to avoid everything that led us to be in danger.

Increase the arrival of blood to the muscles

Faced with danger, animals are programmed to do basically two things: flee or defend ourselves. Be that as it may, we need the muscles to be active. 

For this reason, whether to run or attack, adrenaline encourages the arrival of more blood than normal to the muscles, which increases their strength. 

Dangers of excess adrenaline

However, an excess of adrenaline has unpleasant consequences for the body. Some of them are hypertension, chronic stress, headaches, anxiety, nausea, dizziness, insomnia, temporary vision problems, irritability, heart problems if the level is kept high for a long time and an increase in glucose.

One of the main problems that adrenaline has is the risk of suffering an addiction to its highs, which can even lead to the so-called Pontius syndrome, which causes an alteration of the perception of danger that implies that they are seen as normal activities many high-risk situations, even for one’s life.

FAQS: What part of the brain triggers the release of adrenaline?

Which of the following brain areas is responsible for regulating thirst?

They found early on that the hypothalamus, a deep structure that also controls body temperature, sleep, and appetite, is the primary “thirst center” of the body in the brain. In the hypothalamus, special sensors continuously track the blood concentration of sodium and other substances.

Which part of the brain directs incoming sensory?

The Thalamus is the portion that guides incoming sensory signals to the brain. Explanation: Thalamus serves as the train hub for the vision, hearing and smell of incoming sensory messages. The thalamus receives feedback from the retina, which is transmitted to the brain.

Which of the following is sometimes referred to as the brain’s train hub?

Which of the above is often referred to as the train center of the brain, since it guides incoming sensory signals to their proper positions in the brain (with the exception of smell)? From thalamus.

Which of the following scanning technology measures glucose consumption as an indicator of brain activity?

The researchers concluded that fluorodeoxyglucose (FDG) PET, which tests the intake of glucose in the brain as a neural activity marker, is a better approach to measuring the development and severity of Alzheimer’s and mild cognitive impairment (MCI) compared to amyloid-revealing florbetapir-PET scans.

Which branch of the nervous system calms a person?

The autonomic nervous system consists of two components that function in contrast to each other: the sympathetic nervous system, responsible for the risk response of the body’s fight-or-flight, and the parasympathetic nervous system, which calms down the body.

In this article we answerED the question ‘’What part of the brain that triggers the release of adrenaline?’’ We also talked about what happens to the body when adrenaline is released, how it controls it, things that could happen and what the adrenaline hormone is.

If you have any questions or comments please let us know!


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Chaudhary, R. (2020) “Adrenaline”. Springer Nature Switzerland.

Valenzuela, C., Puglia, M., Zucca, S. (2011) “Focus On: Neurotransmitter Systems”. Alcohol research & health: the journal of the National Institute on Alcohol Abuse and Alcoholism.