Barriers
This physical barrier is the body's first line of defence and prevents most pathogens from entering.
Intact Skin
This process causes redness, swelling, heat and pain following tissue damage.
Inflammatory Response
These lymphocytes mature in the bone marrow and produce antibodies.
B lymphocytes / B cells
Receiving antibodies from breast milk is an example of this type of immunity.
Natural Passive Immunity
These organs filter lymph and are important sites for antigen recognition by T and B lymphocytes.
Lymph nodes
Hydrochloric acid is found here and destroys many pathogens before they reach the intestines.
Hydrochloric acid is this category of barrier
Stomach
Chemical
These white blood cells are usually the first phagocytes to arrive at an infection.
Neutrophils
These cells release cytokines that activate both B cells and cytotoxic T cells.
T-Helper cells
Receiving a vaccine provides this type of immunity.
Artificial active immunity
What is the difference between a self-antigen and a non-self antigen?
A self-antigen belongs to the body's own cells, while a non-self antigen originates from foreign organisms or substances.
Plants protect themselves using this tough outer layer that reduces pathogen entry.
Waxy cuticle
These immune cells engulf pathogens and present their antigens to helper T cells.
Dendritic Cells
These proteins specifically bind to antigens on extracellular pathogens.
Antibodies
Receiving anti-venom after a snake bite is an example of this type of immunity.
Artificial passive immunity
Which type of immune cell is most effective against multicellular parasites such as worms?
Eosinophils
Name TWO examples of microbiota that help prevent infection.
Bacteria on the skin
Bacteria in the digestive tract
This group of plasma moecules punches holes in bacterial membranes and enhances phagocytosis.
Complement Proteins
These cells destroy virus-infected body cells by releasing perforins and granzymes.
This type of immunity generally lasts longer because memory cells are produced.
Active immunity
A virus infects body cells. Which adaptive immune cell will ultimately destroy these infected cells?
cytotoxic T cells
Explain why antibiotics can sometimes increase the risk of infection by opportunistic pathogens.
because antibiotics may destroy beneficial microbiota, allowing harmful pathogens to colonise
Place these events in the correct order:
4 → 2 → 3 → 1
Explain why antibodies are generally ineffective against viruses that are already inside host cells.
Antibodies cannot enter infected cells, so intracellular pathogens must be eliminated by cytotoxic T cells
Explain the difference between active and passive immunity.
Active immunity occurs when an individual's immune system produces its own antibodies and memory cells, whereas passive immunity occurs when ready-made antibodies are received from another source and no memory cells are formed
A student cuts their finger while gardening. Describe the sequence of immune responses from the initial barrier breach until antibody production.