Defense Against Parasitic Infection Flashcards
What are the bodies non-specific defenses?
Physical barriers, chemical secretions, inflammatory response, phagocytes, natural killer cells.
How do epithelial cells protect against parasites?
It blocks the entry of parasites.
How do hydrolytic enzymes in tears and saliva protect against parasites?
By destroying bacterial cell walls.
How do the low pH environments of the secretions of the stomach, sweat glands and vagina protect against parasites?
By denaturing cellular proteins of pathogens.
What do the signalling molecules released by injured cells bring about?
Enhanced blood flow, bringing antimicrobial proteins and phagocytes.
Where are lysosomes found and what do they do?
In phagocytes. They kill parasites using powerful enzymes.
What is the function of natural killer cells?
To identify and attach to cells infected with viruses, releasing chemicals that lead to cell death by apoptosis.
What occurs if tissues become damaged or invaded?
Cell release cytokines that increase blood flow, resulting in non-specific and specific white blood cells accumulate at the site of infection or tissue damage.
What causes a clonal population of lymphocytes to be produced?
The binding of an antigen to a lymphocytes receptor.
What functions can lymphocytes carry out?
Antibody production or apoptosis induction in parasite infected cells.
What gives each antigen the specificity for binding antigen?
Regions where the amino acid structures on each antibody differ greatly.
What can the antibody-antigen complex result in?
Inactivation of the parasite, rendering it susceptible to phagocyte, or can stimulate a response that results in cell lysis. Memory cells are also formed.
What happens when a pathogen infects a second time?
Initial antigen exposure produces memory
lymphocyte cells specific for that antigen that
can produce a secondary response when the
same antigen enters the body in the future.
enhanced in terms of speed of production,
concentration in blood and duration.
