an invasion of body tissues by microorganisms that use the body's environment to multiply and spread disease.
an agent that causes disease
the natural environment for any particular pathogen, where it accumulates in large numbers.
links of the chain
portal of exit
means of transmission
portal of entry
Touching contaminated objects
Breathing airborne pathogens
Bites from infected insects
Drinking or eating contaminated water or food
a response to damaged body tissues designed to kill any pathogens in the damaged tissue, promote healing, and prevent the spread of infection to other parts of the body
tiny regions on the surface of an infectious agent that can be detected by B cells and T cells.
proteins released by B cells that bind tightly to infectious agents and mark them for destruction.
3 types of acquired immunity
naturally- having disease
passively- recieving antibodies
phases of immune response
Phase 1 - Recognition of the invading pathogen
(Macrophages, consume the foreign cells., displaying antigen on their surfaces. Helper T cells "read" this information and rush to respond.)
Phase 2 - Amplification of defenses
Helper T cells multiply rapidly and trigger production of killer T cells and B cells in the spleen and lymph nodes. Cytokines help regulate and coordinate the immune response (interleukins and interferons are two examples). They stimulate increased production of T cells, B cells, and antibodies; promote the activities of natural killer cells; produce fever; and have special antipathogenic properties themselves
Phase 3 - Attack
killer Tcells; cell mediated immunity; B cells are sitmulated by Th cells to produce antibody;
Phase 4 - Slowdown--suppressor T cells halt the immune response
chemical responsible for the dilation and increased permeability of blood vessels in allergic reactions; heat, redness, swelling
white blood cell that travels to the blood stream attacking and killing pathogens
natural killer cells
directly destroy virus-infected cells and cells that have turned cancerous.
immune response (stages again)
Phase 1 - Dendritic cells are drawn to the site
Phase 2 - Helper T cells multiply
Production of Killer T and B cells
Phase 3 - Killer T cells strike
Anti-body mediated immune response
Phase 4 - Last Phase -
ARTIFICIALLY ACQUIRED IMMUNITY (VACCINE)
Introduction of a killed or weakened pathogen to stimulate the body to produce antibodies
the release of histamine and other chemicals into the body leads to a drop in blood pressure, tightening of airways, and possible unconsciousness and even death.
chronic constriction and inflammation of the airways, making breathing difficult and causing shortness of breath, wheezing, coughing, and chest tightness.
Allergic asthma (pollen, venom, peanuts, etc.)
Intrinsic asthma (exercise or cold)
hep A, B, C
cannot multiply without body cell
single cell microorg
meningitis (can be life threatening)
staph- cause toxic shock
MRSA- antiobotic resistant!
pneumonia- #1 cause of death in kids
chlamydia, ghonorrhea, syphilis
must get food from organic matter (tissue)
athletes foot, jock itch, ring worm,
nail bed infections
parasitic worms (helminths)
multicellular; compete with host body of nutrients
tapeworm, pinworm, hookworm
inflammation of the liver that affects liver function.
Hepatitis A - most widespread form, microscopic amounts of feces from contaminated fruits, vegetables, and ice cubes.
Hepatitis B is transmitted through sexual contact.
Hepatitis C is the primary reason for liver transplants in the U.S.
other infectious diseases
H1N1 (swine flu)
H5N1 (avian influenza or bird flu)
SARS (severe acute respiratory syndrome)
West Nile virus
West Nile virus
Severe acute respiratory syndrome (SARS)
Hantavirus - spread by rodents and similar to the flu