AQA AS Psychology Unit 2 Stress Notes
AS Psychology Unit 2: Stress-illness and The Immune System Notes
The immune system refers to the mechanism in the body that provides a defence against infections, e.g. bacteria, viruses, parasites and toxins.
The immune system fights off invaders that cause disease (antigens).
The cells in the system are leukocytes (white blood cells) called phagocytes and lymphocytes.
Phagocytes are the first line of defence, providing a general barrier against antigens.
Leukocytes are more focused and are a second line of defence against specific antigens.
T-lymphocytes (T-cells) attack anything carrying disease in the body.
B-lymphocytes (B-cells) are tuned to a particular antigen, and produce antibodies to destroy them.
Immunosuppression is a reduction in the effectiveness of the immune system and can be caused by stress.
Arnetz et al (1991) - Reduced lymphocyte activity in farm labourers was associated with periods of stressful unemployment.
Irwin et al (1987) - Immune system of recently widowed women functioned at a lower level than age-matched women who had not experienced a stressful event.
Fawzey et al (1993) - Cancer patients who reduced their stress through stress-management during illness showed higher immune system functioning six months after treatment and less likelihood of a recurrence of cancer six years later.
Brady et al (1958) Stress and physical illness
Aim: To investigate whether the stress of receiving electric shocks would lead to stress-related illness in monkeys, and whether this would interact with the degree of control over the shocks.
Procedures:
Monkeys received electric shocks to their feet at 20 second intervals for periods of six hours at a time, with six hours` rest in between
The electric foot shocks were not signalled
Monkeys were run in pairs, with one in each pair - the so called "executive monkey" - able to press a lever to postpone shocks for 20 seconds
The other monkey in the pair could not press the lever, but received
The immune system refers to the mechanism in the body that provides a defence against infections, e.g. bacteria, viruses, parasites and toxins.
The immune system fights off invaders that cause disease (antigens).
The cells in the system are leukocytes (white blood cells) called phagocytes and lymphocytes.
Phagocytes are the first line of defence, providing a general barrier against antigens.
Leukocytes are more focused and are a second line of defence against specific antigens.
T-lymphocytes (T-cells) attack anything carrying disease in the body.
B-lymphocytes (B-cells) are tuned to a particular antigen, and produce antibodies to destroy them.
Immunosuppression is a reduction in the effectiveness of the immune system and can be caused by stress.
Arnetz et al (1991) - Reduced lymphocyte activity in farm labourers was associated with periods of stressful unemployment.
Irwin et al (1987) - Immune system of recently widowed women functioned at a lower level than age-matched women who had not experienced a stressful event.
Fawzey et al (1993) - Cancer patients who reduced their stress through stress-management during illness showed higher immune system functioning six months after treatment and less likelihood of a recurrence of cancer six years later.
Brady et al (1958) Stress and physical illness
Aim: To investigate whether the stress of receiving electric shocks would lead to stress-related illness in monkeys, and whether this would interact with the degree of control over the shocks.
Procedures:
Monkeys received electric shocks to their feet at 20 second intervals for periods of six hours at a time, with six hours` rest in between
The electric foot shocks were not signalled
Monkeys were run in pairs, with one in each pair - the so called "executive monkey" - able to press a lever to postpone shocks for 20 seconds
The other monkey in the pair could not press the lever, but received