13 immunity

functions of the immune system

• protect the body from infectious disease

• involved in tissue repair and protection against potential pathogens

innate immunity

first line of defence against pathogens, general and non-specific

adaptive immunity

built up as we are exposed to diseases or get vaccinated

physical barriers of innate immunity

• skin - physical barrier from physical or chemical damage to the internal organs

• epithelial linings - have cilia to reduce foreign bodies entering the body

• mucosal secretion

chemical innate immunity

• pH of bodily fluid - destroy pathogens

• hormones and other soluble factors - sense potential threats and produce inflammation and cellular death

leucocytes

white blood cells that fight disease

inflammation

widening of local blood vessels that result in an outflow of fluid and immune cells into surrounding tissues

• warmth

• redness

• swelling

• pain

clotting

by platelets to help provide a protective layer around a wound

pathogen

any infectious agent that can cause harm to the body

antigen

foreign chemicals found in pathogen

phagocyte

white blood cells that destroy antigens

T-cell lymphocyte

kills antigen cells directly

b-cell lymphocyte

produce antibodies

antibodies

protein with a chemical “fit“ for certain antigen

lymphocyte and antibody protection

lymphocytes produces specific antibodies to kill particular antigens. antigens can neutralise pathogens in a number of ways and clump them together to be ingested by phagocytes.

antibody to kill pathogen

when lymphocyte meets specific antigen, lymphocyte quickly reproduces and make copies of antibody to kill pathogen

relationship between exercise and susceptibility to infection

higher int. more susceptible to infection due to

• lower leucocyte numbers caused by stress of exercise

• inflammation caused by associated muscle damage

• greater exposure to airborne bacteria and increased rate and depth of breathing

effect of long-term training on the immune system

when training loads are high intensity and go for a long time, there tends to be a decrease in innate and adaptive immune function

impact of sustained cortisol and adrenaline due to intense and long-term training

suppress the immune system, cortisol can prevent the production of t-cells

leucocyte number compared to sedentary people

leucocyte numbers drop compared to sedentary

describe the effects of intense exercise

an intense bout of exercise can cause tissue damage and so is accompanied by responses that are similar to those of an infection such as

• increase in leucocytes

• inflammation

describe strategies for minimising risk from infection among athletes 1

• incorporation of sufficient recovery time into training programs

• avoid close contact with people with infection

• maintain oral hygiene

• maintain hydration status - easier blood movement and immune cells

describe strategies for minimising risk from infection among athletes 2

• ensure water is pathogen free

• maintain good hygiene

• maintain suitable and varied diet

• ensure sufficient sleep