Female stress syndrome: stress and the general adaptation syndrome

Have you noticed how your heart seems to skip a beat or race after a near-accident on the highway? How about an unexpected encounter with a former lover? In each of these instances, your body is responding to signals from your sympathetic nervous system. It can, for example, increase your heart rate from about 70 beats per minute to 140 beats per minute when you are under stress.

Think about your most recent experience with stress. Since this can involve almost any demand or pressure that induced mental or physical tension, an incident will probably come to mind easily. You may remember being upset, frightened, excited, confused, insulted, elated, aroused, disappointed, annoyed, competitive, saddened, sickened, fatigued, exhausted, or surprised.

Stress can result from something happening around us, or from something happening within. It can result from a work problem, a family crisis, or a bout of self-doubt. It can be caused by factors as diverse as the aging of our bodies and the birth of a long-awaited child. It can be intermittent, rapid-fire, or chronic.

The primary effect of stress is to mobilize the body's "fight, flight, or fright" system. This means that stress stimulates the chemical, physical, and psychological changes that prepare us to cope with a threatening situation in these ways. This is all very well, of course, when the stressful situation calls for this type of action; we can easily speculate, for example, that the system evolved back when the "fight" impulse was directed toward defending one's territory or competing for a mate; when "flight" generally meant running for one's life from a wild animal; and when "fright" referred to confrontation with a natural disaster.

Suppose, though—as happens all too often in modern life—that the stress you are confronted with does not require action. Suppose, for example, that you are late for an important appointment and are held up in bumper-to-bumper traffic. No movement, no escape, and no action. In this situation, relaxation would be of more use than the biochemical and psychological changes created by the fight, flight, or fright system.

As Hans Selye pointed out in the 1950s, our stress mobilization system is relatively nonspecific. That is, it mobilizes in a similar way to any strong demand, whether short-term or long-term; whether it requires action or restricts action; whether it brings good news or bad news. Winning a lottery, for example, stresses the body in much the same way as losing a lottery does! Both produce what Selye called the General Adaptation Syndrome—a bodily reaction to stressful situations that involves emergency activation of both the nervous system and the endocrine (hormonal) system.

Within the nervous system, stress messages travel along three pathways. They travel from the brain through motor nerves to arm, leg, and other skeletal muscles, preparing them for motion. They travel from the brain to the autonomic nervous system, which raises blood pressure, heart rate, and blood sugar level; releases reserve red blood cells needed for carrying oxygen to muscles; and slows intestinal movement (since digestion is not a priority in an emergency). And finally, they travel from the brain to the interior of the adrenal gland, which releases adrenaline into the bloodstream as a general stimulant.

The hypothalamus also receives stress messages transmitted from the brain along nervous system pathways, but from there a second system, the hormonal or endocrine system, is activated. This system works more slowly than the nervous system in reaction to stress, but it can maintain its effects on the body for longer periods of time.

Think of the hypothalamus as the emotion control center of the brain. From the hypothalamus, stress messages can be dispatched to many different glands.

When the pituitary is signaled by the hypothalamus, it releases hormones into the bloodstream, which activate the adrenal cortex. The adrenal cortex releases similar hormones, and together they raise the white blood cell count (affecting some immune and allergic reactions), alter the salt and water balance (gradually increasing blood pressure by changing excretion patterns), and stimulate the thyroid gland (increasing metabolism).

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