Dealing with pathogens

Prevent infection
innate immunity
adaptive/acquired immunity
differences between
invertebrates
vertebrates

innate immunity
(all animals)

recognition of traits shared by broad ranges of pathogens, small set
of receptors
rapid response
examples

Adaptive immunity
(vertebrates only)

recognition of traits specific to particular pathogens, vast array of receptors
slower response

Barrier defenses

skin
mucous membranes
secretions
lysozymes stomach acid

internal defenses

phagocyctic cells
natural killer cells
antimicrobial proteins
inflammatory response

human response

antibodies defend against infection in body fluids

Cell-mediated response

cytoxic cells defend against infection in body cells

Pathogens

bacteria,fungi, and viruses

barriers fail: internal defenses

phagocyctic cells
chemical defenses
psuedopodia surround pathogens pathogens engulfed by
endocytosis vacuole forms vacuole and lysosome
fuse pathogens develop debris frm pathogen
released

mammalian immune system

components
barriers innate adaptive

Physical barriers
(mucous membrane)

mucosa of nasal cavity
mucosa of mouth
esophagus lining
mucosa of lung bronchi

Cellular innate defenses

neutrophilis and monocytes
signaling- toll like receptors phagocytosis
eosinophils
multicellular parasites
natural killer cells
apoptosis of irregular cells

chemical innate responses

interferons
complement proteins
inflammatory response

Adaptive immunity

Lymphocytes
b cells T cells

Blood types

Antigens
antibodies
blood typing mechanisms
ABO system Rh factor Many others
transfusion reactions
universal donor's O-
Universal recipent;s AB+

B cells

antigen receptors
specificity
antibody production
antigen binding site

T cells

Antigen receptors
Signaling- cytokines
Killing- perforins

Adaptive immune responses

involve lymphocytes in some way
humoral response= antibodies eliminate pathogens
Cell-mediated response= t cell eliminate pathogens

Antigen presentation

When/ by who?
Phagocytic cells
infected cells
B cells
How?
MHC proteins
Results infected cells

B cells activation

B cells present antigens
how did they get them?
MHC proteins
T cells release cytokines

Cytokines

production
B cell mitosis

After B cells active and cytokines

memory cells develop