• FOLLOWING INJURY, MAST CELLS IN THE TISSUES BECOME ACTIVATED TO PRODUCE
HISTAMINE AND VARIOUS CYTOKINES, WHICH THEN TRIGGER THE START OF THE
INFLAMMATORY RESPONSE.
• HISTAMINE CAUSES VASODILATION AND INCREASED PERMEABILITY OF BLOOD CAPILLARIES.
THIS RESULTS IN AN INCREASED BLOOD FLOW TO THE INFECTED AREA AND ALLOWS OTHER
CELLS OF THE IMMUNE SYSTEM TO REACH THE INFECTED TISSUES.
• CYTOKINES ARE SMALL SIGNALLING MOLECULES THAT ATTRACT PHAGOCYTES TO THE SITE
OF INFECTION. PHAGOCYTES ARE WHITE BLOOD CELLS THAT ENGULF AND DESTROY THE
BACTERIA THAT HAVE CAUSED THE INFECTION, THEY ALSO ENGULF AND DESTROY DAMAGED
TISSUE CELLS.
• THE PRESENCE OF BACTERIA AT THE SITE OF INFECTION STIMULATES ANTIMICROBIAL
PROTEINS KNOWN AS ‘COMPLEMENT’ TO ARRIVE AT THE SITE OF INFECTION. THE
COMPLEMENT SYSTEM HELPS THE BODY TO RID ITSELF OF INFECTION BY AMPLIFYING THE
IMMUNE RESPONSE.
• CLOTTING ELEMENTS ARE ALSO ATTRACTED TO THE SITE OF INFECTION, WHERE THEY ACT
TO PROMOTE COAGULATION OF THE BLOOD. THIS PREVENTS THE SITE OF INFECTION FROM
BLEEDING AND ALLOWS THE INFECTED AREA TO HEAL.

Mast cell
Histamine
Cytokine
Function
White blood cells found in the connective tissue which contain many histamine granules
Chemical causing vasodilation and increased permeability to capillaries
Cell signalling protein molecules which are secreted by cells
Phagocyte White blood cell which engulf and digest (due to lysosomes with digestive enzymes) pathogens
Complement Antimicrobial proteins that amplify inflammatory
Clotting element response
Cause the coagulation of infection site for healing

Non specific immunity
Physical & chemical barriers
Inflammatory
Non-specific
Cellular response
B cells
Specific immunity
Immunological surveillance
Clonal Selection theory
T cells
Immune system diseases
Disease survival mechanisms
Infectious
Disease
Transmission
Epidemiology
Vaccination Public Health

• A RANGE OF TYPES OF WHITE BLOOD CELL
(LEUKOCYTES) CONSTANTLY CIRCULATE,
MONITORING THE TISSUES.
• IF TISSUES BECOME DAMAGED OR INVADED A
VARIETY OF CELLS RELEASE CYTOKINES, WHICH
RECRUIT SPECIFIC WHITE BLOOD CELLS TO THE
SITE OF INFECTION OR TISSUE DAMAGE.
• THIS IS CALLED IMMUNOLOGICAL SURVEILLANCE

• LEUKOCYTES (WHITE BLOOD CELLS) ARE THE MOST NUMEROUS CELLS OF THE
IMMUNE SYSTEM.
• THEY ARE PRODUCED IN THE BONE MARROW AND USE THE BLOOD TO
TRANSPORT THEMSELVES AROUND THE BODY – THEY ARE CONSTANTLY ON
THE LOOKOUT FOR MICROBES, PATHOGENS, ANTIGENS ETC. LEUKOCYTES CAN
LEAVE THE CIRCULATORY SYSTEM AND ENTER THE TISSUES, WHERE THEY
FUNCTION.
• IF THE TISSUES BECOME DAMAGED OR INVADED, LEUKOCYTES ARE CAPABLE
OF SECRETING OVER 100 DIFFERENT PROTEIN MESSENGERS KNOWN
COLLECTIVELY AS CYTOKINES.
• CYTOKINES REGULATE HOST CELL GROWTH AND FUNCTION IN BOTH SPECIFIC
AND NON-SPECIFIC DEFENCES.
• SECRETION OF CYTOKINES CAN TRIGGER A NUMBER OF RESPONSES.
• SOME CYTOKINES ARE CHEMOKINES (CHEMOATTRACTANTS).
• ONCE SECRETED THESE CHEMOKINES ATTRACT PHAGOCYTES (NON-SPECIFIC)
AND T CELLS (SPECIFIC) TO THE SITE OF INJURY.
• THIS STIMULATES AN INFLAMMATORY RESPONSE AS WELL AS AN IMMUNE
RESPONSE.

• NOSY PARKERS
• VIGILANTES
• NEIGHBOURHOOD WATCH
• CCTV
• BIG BROTHER
BECAUSE ......