viernes, 15 de enero de 2016

How stress affects your body

Stress is designed to gives us alertness and energy needed to perform our best. But stress isn’t always good. When activated too long or too often, stress can damage virtually every part of our body. In this Ted-Ed lesson Sharon Horesh Bergquist gives us a look at what goes on inside our body when we are chronically stressed.

Self-study activity:
Watch the video and say whether the statements below are true or false.

1. The hormones cortisol, epinephrine and norepinephrine travel all over the body.
2. Adrenaline results from hypertension.
3. The feeling of butterflies in the stomach is a symptom of stress.
4. Stress makes us lose weight.
5. Having cuts that take longer to heal might be a symptom of stress.
6. Anger is another symptom of stress.
7. A stress-free life is the best course of action.

Cramming for a test? Trying to get more done than you have time to do? Stress is a feeling we all experience when we are challenged or overwhelmed. But more than just an emotion, stress is a hard-wired physical response that travels throughout your entire body. In the short term stress can be advantageous, but when activated too often or too long your primitive fight or flight stress response not only changes your brain but also damages many of the other organs and cells throughout your body.
Your adrenal gland releases the stress hormones cortisol, epinephrine also known as adrenaline, and norepinephrine. As these hormones travel through your blood stream they easily reach your blood vessels and heart. Adrenaline causes your heart to beat faster and raises your blood pressure, over time causing hypertension. Cortisol can also cause the endothelium, or inner lining of blood vessels, to not function normally. Scientists now know that this is an early step in triggering the process of atherosclerosis, or cholesterol plaque build-up, in your arteries. Together these changes increase your chances of a heart attack or stroke.
When your brain senses stress, it activates your autonomic nervous system. Through this network of nerve connections your big brain communicates stress to your enteric, or intestinal, nervous system. Besides causing butterflies in your stomach, this brain gut connection can disturb the natural rhythmic contractions that move food through your gut leading to irritable bowel syndrome and can increase your gut's sensitivity to acid making you more likely to feel heartburn.
Via the gut's nervous system stress can also change the composition and function of your gut bacteria which may effect your digestive and overall health. Speaking of digestion, does chronic stress effect your waist line? Well yes. Coritsol can increase your appetite. It tells your body to replenish your energy stores with energy dense foods and carbs, causing you to crave comfort foods. High levels of cortisol can also cause you to put on those extra calories as visceral or deep belly fat. This type of fat doesn't just make it harder to button your pants. It is an organ that actively releases hormones and immune system chemicals called cytokines that can increase your risk of developing chronic diseases such as heart disease and insulin resistance.
Meanwhile, stress hormones effect immune cells in a variety of ways. Initially they help prepare to fight invaders and heal after injury. But chronic stress can dampen the function of some immune cells, make you more susceptible to infections, and slow the rate you heal. 
Wanna live a long life? You may have to curb your chronic stress. That's because it has even been associated with shortened telemeres. The shoe lace tipped ends of chromosomes that measure a cell's age. Telemeres cap chromosomes to allow DNA to get copied every time a cell divides without damaging the cells genetic code, and they shorten with each cell division. When telemeres become too short a cell can no longer divide and it dies.
As if all that weren't enough, chronic stress has even more ways it can sabotage your health, including acne, hair loss, sexual dysfunction, headaches, muscle tension, difficulty concentrating, fatigue, and irritability. So, what does this all mean for you? Your life will always be filled with stressful situations, but what matters to your brain and entire body is how you respond to that stress. If you can view those situations as challenges you can control and master, rather than as threats that are insurmountable, you will perform better in the short run and stay healthy in the long run.

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