3 Types of Pathogens
Bacteria, Viruses, and Parasites
Immune System
recognizes foreign bodies and responds with production of immune cells and proteins
All animals have ___ immunity
All animals have innate immunity
Vertebrates have ____ and ____immunity
Vertebrates have innate immunity and adaptive immunity.
Innate Immunity
Nonspecific, present at birth, external and internal cells, 1st and 2nd line of defense
Adaptive Immunity
specific, adaptive, 3rd line of defense
1st line of defense(Barrier defense)
Skin/Membranes/Secretions such as sweat, saliva, mucous
Phagocytic Cells
provide non-specific defense, consume pathogens via phagocytosis.
Neutrophilic Cells
highly abundant white blood cell, short lived and highly motile/ self destructing
Macrophages
“Big eaters” long lived
Inflammation
Non specific response to infection or injury
Inflammation Process
mast cells release histamines which dilate blood vessels to a more porous state for white blood cells to move
Cytokines
General signaling molecules
Name of 3rd Line of Defense
Adaptive Immunity
Leukocyte
smaller non phagocytic cells
Lymphocyte
leukocytes in the 3rd line of defense used for specific defense.
Humoral Response
B cells create antibodies for defense against infection in the humoral (body) fluid.
Cell Mediated Response
Cytotoxic cells defend against infection in body cells
Antigen
substances that elicit a response from B and T cells
Epitope
The accessible part of an antigen for antigen receptors to bind to.
Antibodies
mark pathogens for destruction
MHC Major Histocompatibility Complexes
display antigen fragments on the surface of cells so that T cells can recognize cells that need to be destroyed
MHC Class 1
Show off antigen fragments to cytotoxic T cells.
Perforin
little molecules released from cytotoxic T cells that form pores in an infected cell which will fragment and die.
MHC Class 2
Show off antigen fragments to Helper T Cells
Helper T Cells
when activated, will either signal humoral B cells to come bring antibodies, or cell mediated T cell destruction response.
Activated B Cells proliferate into _____ and _____ via _____
Activated B cells proliferate into memory B cells and antibody secreting plasma cells via CLONAL SELECTION.
Immunological Memory
Memory B cells retain specific antigens for a previous battle, causing a faster and more efficient response the second time around.
Antibodies can do 3 things to a pathogen:
Neutralization, Opsonization, Activation of complement systems
Antibodies–> Pathogen: Neutralization
Antibodies surround the pathogen’s activation sites so that they cannot infect any other cells.
Antibodies–> Pathogen: Opsonization
Antibodies create a target for phagocytosis
Antibodies–> Pathogen: Activation of Complement Structure
Antibodies create a protein complex with the pathogen that causes pores in cell and causes lysis.
Allergies: General definition
Exaggerated responses to antigens by excess release of histamines from a mast cell that has had antibodies attach to it.
Autoimmune Diseases (3 examples)
Body loses tolerance for itself. (Graves Disease, Arthritis, Insulin dependent diabetes, multiple sclerosis)
Graves Disease
B cells produce antibodies that bind to the receptors on the thyroid gland… causes excessive release of thyroid hormone.
Insulin Dependent Diabetes
autoimmune destruction of B cells by T cells
Multiple Sclerosis
T cells attack myelin