Stress a normal part of life-II

Teen stress

As one example of stress related to a life transition, the teen years often bring about an increase in perceived stress as young adults learn to cope with increasing demands and pressures along with changes in their bodies. Studies have shown that excessive stress during the teen years can have a negative impact upon both physical and mental health later in life. For example, teen stress is a risk factor for the development of teen depression, a serious condition that carries an increased risk of suicide.

Fortunately, effective stress-management strategies can diminish the ill effects of stress. The presence of intact, strong, supportive social support networks among friends, family, educational and religious or other group affiliations can help reduce the subjective experience of stress during the teen years. Recognition of the problem and helping teens develop stress-management skills can also be valuable preventive measures. In severe cases, a physician or other health-care professional can recommend counselling or other treatments that can reduce the long-term risks of teen stress.

 

What is the healthy response to stress?

A key aspect of a healthy adaptational response to stress is the time course. Responses must be initiated rapidly, maintained for a proper amount of time, and then turned off to ensure an optimal result. An over-response to stress or the failure to shut off a stress response can have negative biological and mental-health consequences for an individual. Healthy human responses to stress involve three components:

* The brain handles (mediates) the immediate response. This response signals the adrenal medulla to release epinephrine and norepinephrine.

* The hypothalamus (a central area in the brain) and the pituitary gland initiate (trigger) the slower maintenance response by signalling the adrenal cortex to release cortisol and other hormones.

* Many neural (nerve) circuits are involved in the behavioural response. This response increases arousal (alertness, heightened awareness), focuses attention, inhibits feeding and reproductive behavior, reduces pain perception, and redirects behaviour.

The combined results of these three components of the stress response maintain the internal balance (homeostasis) and optimise energy production and utilization. They also gear up the organism for a quick reaction through the sympathetic nervous system (SNS). The SNS operates by increasing the heart rate, increasing blood pressure, redirecting blood flow to the heart, muscles, and brain and away from the gastrointestinal tract, and releasing fuel (glucose and fatty acids) to help fight or flee the danger.

 

How does the response to stress work?

While the complete story is not fully known, scientists understand much about how the response to stress works. The two main systems involved are the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system (SNS). (These systems are described later.) Triggered (activated) primarily by an area in the brain stem (lowest part of brain) called the locus coeruleus, the SNS results in the secretion of epinephrine and norepinephrine. The following are the five most important concepts to remember about these two systems:

1. They are governed by a feedback loop to regulate their response. (In a feedback loop, increased amounts of a substance - for example, a hormone - inhibit the release of more of that substance, while decreased amounts of the substance stimulate the release of more of that substance.)

2. They interact with each other.

3. They influence other brain systems and functions.

4. Genetic (inherited) variability affects the responses of both systems. (That is, depending on their genes, different people can respond differently to similar stresses.)

5. Prolonged or overwhelming responses of these systems can be harmful to an individual.

 

What is the role of the

hypothalamus-pituitary-adrenal axis (grouping) in stress?

The HPA axis is a grouping of responses to stress by the brain and the pituitary and adrenal glands. First, the hypothalamus (a central part of the brain) releases a compound called corticotrophin releasing factor (CRF), which was discovered in 1981. The CRF then travels to the pituitary gland, where it triggers the release of a hormone, adrenocorticotrophic hormone (ACTH). ACTH is released into the bloodstream and causes the cortex of the adrenal gland to release the stress hormones, particularly cortisol, which is a corticosteroid hormone. Cortisol increases the availability of the body’s fuel supply (carbohydrate, fat, and glucose), which is needed to respond to stress. However, if cortisol levels remain elevated for too long, then muscle breaks down, there is a decreased inflammatory response, and suppression of the immune (defence) system occurs.

Corticosteroids in measured doses are used to treat many illnesses that are characterized by inflammation or an overactive immune system, such as asthma and inflammatory bowel disease. For the same reason, they are used to help reduce the chances that our body will immunologically reject a transplanted organ. Corticosteroids also can cause fluid retention and high blood pressure. Therefore, it is critical that the response to corticosteroids be carefully controlled (modulated). This control usually is accomplished by a feedback mechanism in which increased cortisol levels feeding back to the hypothalamus and pituitary turn off production of ACTH. In addition, extremely high levels of cortisol can cause mental changes, including depression and psychosis, which disappear when the levels return to normal.

— medicinenet.com