Why Zebras Don't Get Ulcers summary

Remember the last time someone scared you silly by jumping out from behind a door? In that moment, you were suddenly wide awake, focused and felt every fiber in your body. But what exactly causes us to feel that way?

This reaction is caused by the autonomic nervous system, which ensures that our bodies function without our conscious control. It automatically directs all our involuntary actions, such as blushing, breathing, getting goosebumps or having orgasms.

Imagine an exciting vacation is just days away, but you have a stressful few days at work and you get sick. Bummer! As it turns out, this rain on your parade is characteristic of how the human body handles stress. But to figure out how, we’ll need a lesson in biology.

For all mammals, stress is about maximizing the energy that muscles have available to them.

If you’ve ever turned on the water in your garden without holding onto the hose, then you probably noticed how stiff the hose gets as the water flows through at high speed. When stressed, something similar happens inside your body that can be quite dangerous over time.

When you’re under stress, the muscles around the walls of your veins tighten, pushing the blood through at a higher speed. Once the blood reaches the heart, it slams into the walls of the heart, which, like a rubber band, snaps back, causing the heart rate to increase.

In the previous blink, we talked about the vital role that the cardiovascular system plays in distributing much-needed energy to your muscles during times of stress. But where does that energy come from?

After a meal, you have more nutrients in your body than you need at that moment. So, the body breaks down the food into its smallest components – amino acids, glucose and fatty acids – which are then stored in various places, like your liver and fat cells.

Most people know someone who suffers from depression. In fact, studies estimate that somewhere between five and 20 percent of all people will suffer through a major depression at one point or another. But what effect does depression have on the body?

Depression, the loss of an ability to feel pleasure accompanied by incapacitating grief and guilt, is a profoundly destructive condition that can have huge consequences for an individual's life. Indeed, studies project that depression will be the second-leading cause of medical disability globally by 2020.

If you know anything about marketing, then you know that “sex sells.” Unfortunately, with all the media coverage, half-truths and titillating stories about how great it can be, sex is one of our greatest sources of stress, and is itself profoundly influenced by stress.

For men, stress leads to premature ejaculation and difficulty achieving an erection. The process of getting an erection is managed by the parasympathetic autonomic nervous system, which, as you recall, is responsible for slowing the body down. One has to be calm and relaxed to get an erection – that is, the opposite of stressed.

So far you’ve seen some of the many negative consequences of stress. But as you’ll soon discover, these are just the tip of the iceberg.

Over time, scientific perspectives on how the body manages stress have changed. Scientists once believed that the body functions according to the homeostatic principle, which asserts that problems in the body can be corrected with a single local adjustment.

What do you do when you’re feeling stressed? Do you try to grab the problem by the horns yourself, or turn to a friend for help? As you’ll see, both of these strategies work just fine.

Taking responsibility for stressful situations can bring relief as you regain a bit of control over your life.

Up to this point, we’ve mentioned numerous examples of isolated incidents that contribute to stress, like fleeing predators or pre-test anxiety. But some stressors, like poverty, go beyond isolated incidents and can cause chronic stress.

In fact, being poor is associated with many physical and mental stressors. Poor people often work jobs with high physical demands and low job security, leaving them with little control over their work situation and high levels of stress.

The last blink demonstrated how poor socioeconomic status can have a negative impact on our health. But what socioeconomic factors can contribute to creating a healthier society?

For one, communities with high social capital enjoy higher equity and better health. Similar to financial capital, social capital refers to the resources you can draw upon in times of trouble, like having friendly neighbors who can babysit for you when you need to work overtime. In communities with high social capital, people are less socially isolated.