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.
· 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…