Stress related illness: The immune system

The Immune System = a network of cells and chemicals throughout the body that functions to seek out and destroy invading particles. 

• anything that stimulates an immune response = AN ANTIGEN
• ANTIGENS prtect the body against : bacteria, viruses, toxins ect.

How does the immune system operate? - it protects you in 3 different ways:

1. creates a barrier preventing antigens from entering your body
2. if an antigen does enter your body, the immune system tries to detect and eliminate it before it can reproduce
3. if virus is able to reproduce and start causing problems, the immune system is responsible for elimating it. 

White blood cells / leucocytes

there are two types of white blood cells:

1. phagocytes = these surround and ingest the invading foreignparticles - ingests bacteria
2. lymphocytes = these produce antibodies which attach themselves to the foreign particles, slowing them down and making it easier for other immune cells to destroy them - produces antibodies

Research into stress and immune system functioning 

Kiecolt-Glaser et al (1984) - found a decrease in immune cell function

Aim: to see if stress of short-term stressors have an effect on immune system functioning in medical students. 

Method: blood samples taken 1 month before (kow stress) and during (high stress) exam period. Immune system functioning assessed by NK (natural killer) cell activity in bloody samples. Patricipant's also completed a questionnaire to meausre other life stressors they may be experiencing. 

Findings: NK cell activity significantly reduced in 2nd blood samples compared to sample taken 1 month before

Conclusions: short-term stressors reduce immune system functioning, increasing vulnerability to illness. 

AO2: 

• Study high in ecological validity because…