AQA AS Psychology Unit 2: Stress illness and The immune system 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…