Fight or Flight: Stress Response & Recovery -Nicolette V.

Main Stress Response Hormones

The 3 main hormones that respond to our stress are epinephrine (adrenaline), cortisol, and norepinephrine .

1. Epinephrine:

• The hormone epinephrine is also called adrenaline and prepares the body for a fight or flight response. It increases the heart rate, breathing rate, opens the airways for better air flow, dilates blood vessels in the skeletal muscles, and mobilizes energy stores.
• In a stressful situation your adrenal glands signal to produce adrenaline. For example, if you're changing car lanes and there is a car beside you. Your heart beat will rapidly increase, and you will breath faster. This is your adrenaline taking place.

2. Norepinephrine:

• Norepinephrine is very similar to adrenaline and this hormone causes you to become more awake and acts like a backup from adrenaline.
• This hormone has some of the same effects as epinephrine, but also increases blood pressure and affects the amygdala.
• Both epinephrine and norepinephrine influence the conversion of glycogen and glucose and also the conversion of fats to fatty acids, which increases the energy supply and prepares the muscles to be able to respond if they are needed.

3. Cortisol:

• This hormone promotes and pushes amino acids to convert into glucose and it influences fats to convert into fatty acids. The glucose increases our blood flow and the fatty acids increase our heart rate and speed up our breathing.
• Cortisol is a steroid hormone also produced by the adrenal gland, but instead of reacting immediately it takes a couple minutes. First your amygdala in your brain signals that there is a threat and brings this message to your hypothalamus which signals to produce an CRH hormone and this hormone signals to produce the ACTH hormone. After all these steps, the ACTH hormone signals to your adrenal gland to make cortisol.
• This stress hormone is also captured in the hair shaft and there is a link between the cortisol levels in hair and the risk of having a stress-related heart attack (Klein, 2013).

Some other stress hormones are:

• Glucagon: glucose is converted to glycogen to increase blood sugar
• Insulin: will decrease in production which will increase blood sugar level
• Antidiuretic hormone (ADH): retains water to increase blood pressure

Adrenaline and noradrenline are two separate but related hormones and neurotransmitters.They are produced in the medulla of the adrenal glands and in some neurons of the central nervous system. They are released into the bloodstream and serve as chemical mediators, and also convey the nerve impulses to various organs. Adrenaline has many different actions depending on the type of cells it is acting upon. However, the overall effect of adrenaline is to prepare the body for the ‘fight or flight’ response in times of stress, i.e. for vigorous and/or sudden action. Key actions of adrenaline include increasing the heart rate, increasing blood pressure, expanding the air passages of the lungs, enlarging the pupil in the eye (see photo), redistributing blood to the muscles and altering the body’s metabolism, so as to maximise blood glucose levels (primarily for the brain). A closely related hormone, noradrenaline, is released mainly from the nerve endings of the sympathetic nervous system (as well as in relatively small amounts from the adrenal medulla). There is a continuous low level of activity of the sympathetic nervous system resulting in release of noradrenaline into the circulation, but adrenaline release is only increased at times of acute stress