In the Fight or Flight Response, we were either going to prepare to fight against these threats or dangers, or we were gonna prepare to run away from these threats or dangers. So the fight or flight response that Cannon was so interested in, revolves around the inner workings of the nervous system and the endocrine system. So on the nervous system side of things, We have the sympathetic nervous system. We have our brain and our spinal cord that make up the central part of our nervous system. Part of our nervous system that we don't always think about or aren't thinking about control is the autonomic nervous system.
A branch of that autonomic nervous system that's going on behind the scenes is the sympathetic nervous system. And this is the aspect of our nervous system that's gonna transition our body into the get out of danger mode. And so, with that, we'll see increased heart rate in order to pump blood with oxygen and nutrients all around our body. So we have an increased heart rate, increased respirations. So we have an increased respiratory rate. And that gives us the ability to get more oxygen into our blood and all the way to our tissues. And it gives us the ability to expel more carbon dioxide as a waste product from our muscle work. And then we're also gonna see increased peripheral vasoconstriction. So the blood vessels in our peripheral parts of our body, like our arms and our legs, are gonna clamp down and they're gonna tighten in order to push more blood to our core area. Because our arms and legs are important, we can live without them. It would be a lot harder to live without our brain or our vital organs, so we need a lot of our blood forced into those really crucial areas. And then lastly, we're gonna turn off less important things, like digestion and immune function and ovulation, because these things are great if we're just hanging out, but they're definitely less crucial in life-or-death situations. So teaming up with the sympathetic nervous system, we have the endocrine system.
And so the endocrine system is gonna supply some of the hormones. And the two biggest hormone players actually come out of the same organ, which sits on top of our kidneys, the same organs. And those are your adrenal glands. From the medulla, we get our catecholamine hormones. And our catecholamine hormones include epinephrine and norepinephrine. So sometimes those are more often called adrenaline and noradrenaline. But these are the hormones that are major communicators for increasing the heart rate and blood pressure and otherwise communicating that sympathetic response that we just talked about. So those are really supporting the sympathetic nervous system, these hormones coming out of the adrenal medulla. And then on the outside, this bolder part of our adrenal gland, that's called the cortex. And out of the cortex come some other major stress hormones. And the biggest one is a glucocorticoid called cortisol. But cortisol is a steroid hormone that contributes to the stress response by redistributing glucose energy in the body and suppressing the immune system. We have this fight-or-flight response to stressors. So we're preparing to either fight or run away. And that's being communicated by our sympathetic nervous system, which is assisted by the hormones of our endocrine system. And so we have this fight or flight response that Dr. Cannon coined the terminology of. But we also have another response called Tend and Befriend. We're calling this affiliative response the tend or befriend response. Because it turns out that sometimes a better response to stress is to huddle together and form support systems. And an important biological component of this response is the hormone oxytocin. And oxytocin is associated with things like pair bonding. And so it can moderate this stress response. And it's really interesting if you know much about oxytocin, it's majorly integrated with the hormone estrogen.
And so estrogen is a major sex hormone in women. And so what follows is kind of a naturally greater disposition to this tend and befriend response in women much more so than in men. And so we have these two major categories of response to stressors. We have this fight or flight response and this tends and befriend response. For General Adaptation Syndrome, it has three phases. The first phase is the alarm phase, in this alarm phase, that stress reaction kicks in. So your heart starts racing, and your resources are mobilizing. You're ready to fight or to run for your life. In the second phase, called the resistance phase, we're actually fighting or fleeing, or huddling together. Our temperature is elevated and our blood pressure and rate of breathing remain high. And we're also bathing our bodies in the stress hormones like cortisol. And so our body has reserves to react to those acute stressors in this resistance phase, but those reserves only go so far. And that brings us to the third phase of the G.A.S., and that's exhaustion. So if the resistance stage isn't followed by recovery, the body's stress resources get depleted and it leads to exhaustion. Our tissue and muscles become damaged and our dampened immunity can make us really susceptible to illness. All around exposure to stress can have some really damaging effects. Because like many animals, our body's pretty well equipped to handle short-term stress, but the problem is that when we apply those life-saving stress reactions to our daily commute and to our 9 to 5 jobs, and other psychosocial trivialities of life, we end up spending way too much time experiencing the negative consequences of stress, this exhaustion consequence. And it has some pretty nasty consequences.