2402 Ex 3 Set 1

Immune functions

surveillance, recognition, and destruction of foreign substances

Why is the immune system not a body system?

no organs, rather cells, molecules, proteins

foreign substances that can cause disease are referred as

pathogens

5 pathogens

bacteria, viruses, fungi, protozoa, multicellular parasites

first line of defense

skin & mucous membrane

Skin & Mucous Membrane is…

physical, chemical, and biological barrier

Skin & Mucous Membranes…

must be compromised to allow entry of pathogens

infectious dose (ID)

# of individual particles need to enter body to make sick, varies by pathogen, quite a few

second line of defense

nonspecific internal defenses

nonspecific internal defenses

Non-specific cells, chemicals, physiologic responses

third line of defense

adaptive immunity

tlod: specific activation and response

t lymphocytes: cell mediated immunity

b lymphocytes: humoral immunity→ plasma cell→ antibodies