Adrenaline

Adrenaline.
Adrenaline (also referred to as epinephrine) is a hormone secreted by the adrenal glands which are located on top of the kidneys. These glands secrete adrenaline directly into the blood stream when someone experiences fear, excitement or high stress conditions and is most commonly known as a ‘fight and flight’ hormone.
There are many causes of adrenaline surges. These are:
  1. Addictions - The body has a natural chemical that gives a feeling of a natural high.
  2. Alcohol - The acetaldehyde which escapes to the blood can encourage the release of adrenaline and dopamine, but in general the level of concentration of acetaldehyde is too low for that.
  3. High Intensity Exercise - As exercise intensity increases, neural messages are sent to the adrenal glands which in response secrete adrenaline into the bloodstream
  4. Life-Endangering Situations – During the presence of a life-endangering situation adrenaline gets released (adrenaline may also be released during artificial life-endangering situations, such as by watching horror movies or computer games). Adrenaline prepares the body for defense in the case of an emergency.
  5. Stimulants – When somebody consumes caffeine, cocaine, and heroin their body closes blood vessels in the brain, so the brain and body cannot sleep. Therefore adrenaline is released.

To help the ‘fight and flight’ our heart rate is boosted and our rate of breathing increases. As your breathing rate increases it allows for more oxygen therefore more respiration, resulting in extra energy being stored ready to be used when needed. It also speeds up the conversion of glycogen to glucose in the liver because glucose is the substrate for respiration (producing energy). Your pupils dilate this is to help improve your vision. Adrenaline prepares you for emergency situations and so it directs most of the blood supply to the skeletal muscles that help us run or fight.