Full Answer
A number of regions in the brain are involved in sensing and responding to stimuli that result in the fear response. The main portion of the brain involved in the fear response is thought to be the amygdala. This small region of the brain is part of the limbic system, processing emotions and unconsciously perceiving fearful stimuli.
The fear response is a complex cascade of chemical and electrical signaling triggered by the autonomic nervous system, the involuntary part of the central nervous system.
The hypothalamus is involved in the fight or flight response. Central projections from the amygdala interact with the hypothalamus, as well as the brain stem, to stimulate the behavioral and physiological reactions of fear, including those of the cardiovascular system. The interaction appears to be mediated by oxytocin.
Memory plays a role in fear because it gives the stimulus context, and the hippocampus is involved in fear learning and conditioning. Lesions in this region of the brain can result in inappropriate fearful responses.
AmygdalaAmygdala. The amygdala helps coordinate responses to things in your environment, especially those that trigger an emotional response. This structure plays an important role in fear and anger.
The amygdala (B) Amygdala connectivity with other brain structures, emphasizing its participation in multiple networks that process fear, and its central location in mediating between parts of the prefrontal cortex and nuclei in the hypothalamus and brainstem.
Fear is experienced in your mind, but it triggers a strong physical reaction in your body. As soon as you recognize fear, your amygdala (small organ in the middle of your brain) goes to work. It alerts your nervous system, which sets your body's fear response into motion.
Fear starts in the part of the brain called the amygdala. According to Smithsonian Magazine, “A threat stimulus, such as the sight of a predator, triggers a fear response in the amygdala, which activates areas involved in preparation for motor functions involved in fight or flight.
As one of the two main parts of the central nervous system, the brain is responsible for controlling all of the body's actions. Everything from walking around the neighborhood to typing a term paper to solving a complex calculus equation depends upon the brain. It also allows one to speak and also to remember.
The brain is divided into four main regions —cerebrum, brain stem, diencephalon, and cerebellum—and has many functions, including receiving and processing information from the internal and external environment, controlling motor function, thinking, decision-making, language, and memory.