Flashcards in 12.3 Stress And Health Deck (50):
____ ____ emphasises the effects on health of diet, smoking, exercise, stressful experiences, and other behaviours.
Hands Selye defined _____ as the non-specific response of the body to any demand made upon it.
Selye inferred that any threat to the body, in addition to its specific effects, activated a generalise response to stress, which he called the ____ ____ ____.
general adaptation syndrome
The initial stage of general adaptation syndrome, which he called ____, is characterised by increased activity of the sympathetic nervous system, readying the body for brief emergency activity.
During the second stage of general adaptation syndrome, _____, the sympathetic response declines, but the adrenal cortex secretes cortisol and other hormones that enable the body to maintain prolonged alertness, fight infections, and heal wounds.
After an intense, prolonged stress, the body enters the third stage of the general adaptation syndrome, ____. During this stage, the individual is tired, inactive, and vulnerable because the nervous system and immune systems no longer have the energy to sustain their heightened responses.
Bruce McEwan (2000) propose an alternative definition of ____ that is better for most purposes: "events that are interpreted as threatening to an individual and which elicit physiological and behavioural responses".
The idea remains that many kinds of events can be ____, and the body reacts to all kinds of stress in similar ways.
Stress activates two body systems. One is the sympathetic nervous system, which prepares the body for brief emergency responses. The other is the ____ ____ – the hypothalamus, pituitary gland and adrenal cortex.
Activation of the hypothalamus induces the anterior pituitary gland to secrete ____ ____ (ACTH), which in turn stimulates the human adrenal cortex to secrete cortisol, which enhances metabolic activity and elevates blood levels of sugar and other nutrients.
Many research is referred to ____ as a "stress hormone" and use measurements of cortisol level as an indication of someone's recent stress level.
Compared to the autonomic nervous system, the HPA axis reacts more slowly, but it becomes the dominant response to ____ ____, such as living with an abusive parent or spouse.
Stress that releases cortisol helps the body mobilise its energies to fight a difficult situation, but the effects depend on ____ and ____.
amount and duration
Brief or moderate stress ____ attention and memory formation. It improves performance on relatively simple tasks, although it impairs performance that requires complex, flexible thinking.
Stress also enhances activity of the ____ ____, helping it fight illnesses.
However, ____ stress impairs memory and immune activity.
The ____ ____ consists of cells that protect the body against viruses, bacteria, and other intruders.
The immune system is like the ____ ____: if it is too weak, the "criminals" (viruses and bacteria) run wild and create damage. If it becomes too strong and unselective, it starts attacking "law-abiding citizens" (the bodies own cells).
When the immune system attacks normal cells, we call the result an ____ ____. Myasthenia gravis and rheumatoid arthritis are examples of autoimmune diseases.
The most important elements of the immune system are the ____, commonly known as white blood cells.
We distinguish several types of ____, including B cells, T cells, and natural killer cells.
____, which mature mostly in the bone marrow, secrete antibodies, which are Y-shaped proteins that attach to particular kinds of antigens, just as a key fits the lock.
Every cell has surfaced proteins called ____ (antibody-generator molecules), and your body's antigens are as unique as your fingerprints.
The B-cells recognise the "self" antigens, but when it finds an unfamiliar antigen, they ____ the cell. This kind of attack defends the body against viruses and bacteria.
After the body has made antibodies against a particular intruder, it "____" the intruder and quickly builds more of the same kind of antibody if encounters that intruder again.
____ mature in the thalamus gland. Several kinds of T-cells attack intruders directly (without secreting antibodies), and some help other T-cells and B-cells to multiply.
____ ____ ____, another kind of leucocytes, attack tumour cells and cells that are infected with viruses. Natural killer cells attack all intruders.
Natural killer cells
In response to an infection, leucocytes and other cells produce more proteins called ____ that combat infections and also communicate with the brain to elicit appropriate behaviours.
Cytokines trigger the ____ to produce fever, sleepiness, lack of energy, lack of appetite, and loss of sex drive.
The immune system also reacts to infection by increased production of ____, additional chemicals that promote sleepiness.
Cytokines and prostaglandins are responsible for what Selye called the ____ ____ ____.
general adaptation syndrome
The nervous system has more control than we might have guessed over the immune system. The study of this relationship, called ____, deals with the ways experiences alter the immune system and how the immune system in turn influences the central nervous system.
Stress affects the immune system in several ways. In response to a stressful experience, the nervous system activates the immune system to increase its production of ____ ____ ____ and the secretion of ____.
natural killer cells : cytokines
The elevated cytokine levels help combat infections, but they also trigger the brain to produce the same symptoms as if one were ___.
Many of the symptoms of ____, such as loss of interest and loss of appetite, are similar to those of illness and are probably related to the increased cytokines found in depressed people.
If you have been under much stress and start to feel ill, one possibility is that your symptoms are reactions to ________.
the stress itself
A prolonged stress response is as ____ on the body is a prolonged illness would be.
A likely hypothesis is that prolonged increase of cortisol directs energy toward increasing ____ and therefore detracts energy from synthesising proteins, including the proteins of the immune system.
Prolonged stress can also harm the ____. Stress releases cortisol, and cortisol enhances metabolic activity throughout the body. When metabolic activity is high in the hippocampus, its cells become more vulnerable. Toxins or overstimulation are then more likely than usual to damage or kill neurons in the hippocampus.
High cortisol levels may also be responsible for the deterioration of the hippocampus and decline of memory that occur in many ____ ____.
In humans, resilience in the face of stress correlates with stronger connections between the ____ and the ____ cortex.
amygdala and the prefrontal cortex
People have found many ways to control their ____ ____. Possibilities include special breathing routines, exercise, meditation, and distraction, as well as, of course, trying to deal with the problem that caused the stress.
____ ____ is one of the most powerful methods of coping with stress, and researchers have demonstrated its effectiveness.
People have wrong recognised that many soldiers returning from battle are prone to continuing anxieties and distress. In the past, people called this condition battle fatigue or shellshock. Today, they call it ____ ____ ____ (PTSD).
post-traumatic stress disorder
PTSD occurs in some people who have endured ____ experiences, such as a life-threatening attack or watching someone get killed.
The ____ of PTSD, lasting at least a month after the event, include frequent distressing recollections (flashbacks) and nightmares about the traumatic event, avoidance of reminders of it, and vigorous reactions to noises and other stimuli.
Other studies have confirmed that people showing the ____ distress shortly after a traumatic event are not necessarily the ones who later develop PTSD.
Most PTSD victims have a smaller than average ____.
Perhaps people with ___ ____ levels are ill-equipped to combat stress and therefore more vulnerable to the damaging effects of stress and more prone than other people to PTSD.