Fight or Flight Response - Assignment Example

Within a split second he moved back and almost stumbled by the lack of balance. He started to gasp as if he was choked and breathing rate elevated. He ran in an unknown but opposite direction of that source of fear. In no time he was perspiring like a waterfall. But after few minutes of disorganization he returned to his normal state. This is a classical scenario of flight and fight response. Walter B. Cannon was a physiologist who first outlined fight and flight as a chain reaction of biological changes that prepares the body for combat in response to a dangerous stimulus (Davis et al 2000).

Our various body functions are controlled by biochemical mechanisms that regulate our biological system. The physiology of the response exhibited by Mr. Paul in the above scenario can be explained by changes that are bought up by our sympathetic system. Functionally, our nervous system can be divided into somatic and autonomic nervous system, not to confuse with central and peripheral nervous system that is a division based on anatomic location. Autonomic nervous system can further be classified into sympathetic and parasympathetic nervous system.

The parasympathetic nervous system is mostly involved in the process of reserving the body's energies. Whereas, sympathetic nervous system regulate biochemical processes that utilize body resources to quickly provide with the energy and changes required to combat an external dangerous stimuli. It’s important to take an in depth analysis of what are these changed how these changes are achieved by this system. The basic physiology: The sensory nervous system provides the cerebral cortex with the stimuli that is classified as dangerous.

This designation of any stimuli as harmful is based on previous experiences or presumptions made by brain based on the processed information throughout life (Hellriegel et al 1979). Not only the sensory stimuli but psychological stimuli can also trigger a fight and flight response. For example giving a speech in front of a vast audience may be able to be a psychological stimuli leading to stage fear (Plotnick et al 2002). Once cerebral cortex perceives any stimuli, sensory or psychological, to be dangerous or capable of inducing flight or fight response a signal is sent to the hypothalamus to activate the sympathetic system.

Sympathetic Response: On arrival of the signal, hypothalamus responds by two main mechanisms. Most of the biochemical changes are produced by these mechanisms. First it stimulates the pituitary gland to secrete a hormone called Adrenocorticotropic Hormone (ACTH). This hormone stimulates the release of corticoids that promote availability of glucose for metabolism throughout the body. Secondly, hypothalamus activates the sympathetic system. Sympathetic nervous system innervates most of the visceral organs of the body.

Alpha and beta receptors on most of the vital organs are stimulated by this system causing increase in the heart rate and respiratory efforts while reducing the gut motility. Therefore, during or after this response victim may experience gastric discomfort and constipation. Sympathetic nervous system also innervates the blood vessels. Therefore, vasoconstriction is an important change brought about by the sympathetic nervous system. It elevates blood pressure by increasing the total peripheral resistance of the body.

Sympathetic activation of nervous system also triggers an important organ, the adrenal glands. These glands are responsible for the secretion of epinephrine and