Symptoms of Infected Wounds
What is pus?
Thick fluid produced during infection.
Why does pus form at the site of infection?
Accumulation of dead neutrophils, bacteria, and tissue debris
How do viruses insert genetic material?
Via endocytosis (non-enveloped) or through fusion with the plasma membrane (enveloped)
What is fever and how does it initiate?
An increase in internal body temperature (pyrexia). The release of cytokines by immune cells signals the hypothalamus to increase the body temperature.
Why is a foul odour produced?
Bacterial byproducts and tissue breakdown.
How do extracellular bacteria cause infection?
They reside outside of cells and release toxins which damage and kill cells.
What is lymphangitis?
Infection/inflammation of the lymph vessels. In this case, the bacterial infection of the burn wound spreads to the lymph nodes and can cause them to become sore and tender.
What is the cause of heat at the infection site?
Increased blood flow (vasodilation) and increased metabolic activity during the immune response.
How is inflammation triggered?
Mast cells within blood vessels will recognise an infection/injury, causing them to release histamine.
What is lymphadenopathy?
Swelling or enlargement of the lymph nodes. Usually in response to a bacterial, viral or fungal infection.
Why does swelling occur?
Increased capillary permeability allows fluid and immune cells to enter the tissue.
What is the role of complement in the immune response?
Many roles: activate mast cells, attract phagocytes (neutrophils, macrophages…) to site of infection, enhance phagocytosis, and the formation of the membrane attack complex.