4.2 Immunity Flashcards
Natural Barriers to Infection
Skin, Tears , Mucus and Acid
Skin ?
Water proof and produces sebum - an oily substance with antiseptic properties ALSO produces sweat - a mixture of chemicals that includes lattice acid and lysozymes . It also impenetrable to pathogens
Tears ?
Protect the eye removing dust that may contain bacteria. They also contain enzymes called lysozymes.
Lysozymes?
They digest the cell walls of bacteria resulting in death
Mucus ?
Acts as an impenetrable barrier to pathogens in is found in many organ systems e.g the respiration , digestive and reproductive. It also contains lysozymes
Acid ?
In the stomach HCl ( gastric juice) has low pH and affects the enzyme action allowing the body to protect itself.
Pathogens
A disease causing mircorganism
Antibodies ?
Globular proteins produced by the lymphocytes (white blood cells) in the presence of a specific , * usually * foreign , antigens
What do Antibodies do
They can join with a foreign antigen and neutralise or destroy or inhibit
Antigens
Are proteins that appear on the cell surface enabling them to recognise each other
Antibody mediated immunity is known as
Hummoral immunity
Pandemic
disease that spreads through a population across wide geographical areas and affect a exptionaly high proportion of the population
Epidemic
An outbreak of a disease that spreads rapidly among individuals on a local or national level
If a pathogen enters the body the capillieries become.…?
Leaky, as plasma escapes, the area becomes swollen ( known as the inflammatory stage ) but more importantly phagocytic white blood cells exit the capillaries.
The phagocytic cells being…?
polymorphs => most common and the first to arrive
macrophages => develop from monocytes in the blood and are larger and survive longer
