Immune and Epidemiology

examples of 1st line of defense

Skin- physical barrier
Saliva & tears- antimicrobial proteins)
Cilia in lungs (sweep dust so it exists when you exhale)
Gastric juices- (stomach acid)
Good bacteria- (mutualistic) already taking up the real estate
Mucus- (physically trap pathogens)

the 1st line of defense is...

a physical defense barrier

defense line 1 & 2 are...

innate (there is no adaptation to them)

Phagocytes

(macrophages & natural killer cells) AKA WBC

What do phagocytes do?

Pull pathogens cells & will stretch plasma membrane around the invader and digest it

Interferons are...

substances secreted by cells invaded by viruses that stimulate neighboring cells to produce protein for themselves

Inflammatory Response

a series of nonspecific events that occur in response to pathogens

Histamine is secreted by

WBC called basophils

Vasodilation increases

blood pressure & causes redness

what causes inflammation when vasodilation occurs?

White cells are sneaking out

Complement proteins

help the phagocytes engulf invaders

What makes it easier for WBC to escape

Increasing the size of cells (blood) make them porous

What's the 3rd line of defense against pathogens?

immune response (A part of the adaptive immune system)

does the 3rd line Targets specific antigens

yes

major histocompatibility complex (MHC) ...

distinguishes self from, non-self

primary agents of the 3rd line of defense

lymphocytes which are made in the bone marrow are stored in lymph nodes

B-cells Have antigen receptors called

antibodies (made up of 2 heavy chains & 2 light chains)

what do they produce when B-cells encounter antigens that bind to their antibodies?

2 things: Plasma cells & Memory cells

Memory cells are

long-lived B cells that do not release antibodies until the antigen is encountered in the future

Plasma cells

B-cells that release specific antibodies

humoral response

Use of antibodies to fight disease

passive immunity

Antibodies can also be given from a mother to her child prior to birth.

Artificial passive immunity

can also occur when antibodies are transferred from one individual to another by nonnatural means

T-cells are...

lymphocytes that mature in the thymus gland

Cytotoxic T-cells (killer)...

recognize & destroy specific pathogens puncturing them

Helper T-cells

stimulate the proliferation (growth) of B-cells & killer T-cell

cell mediated response

The use of T-cells to fight disease

Epidemiology

Study of the occurrence, distribution & control of disease in a population

Epidemiologist study...

how many people have a certain disease in a given time period

Epidemiologist examine...

regions of the country/world where it occurs & how its distributed

Epidemiologist determine...

best strategies to prevent the spread

How many infections are needed for an epidemic to occur?

any number larger than normal

Pandemics

world-wide infections/epidemics

Ex of pandemics

Spanish Flu in 1918, Bird Flu of 2007

What factors can lead to a pandemic? (most important)

ability to travel around the world\###