Ch 43 Immune System Flashcards
How does the immune system prevent infection by parasites?
It responds with production of immune cells or products that target foreign bodies
Two types of immune defense responses?
1) Innate immunity
2) Acquired immunity
Innate immunity
The set of defenses present from birth
Present before exposure to pathogens
Pathogens
Cause of disease
Innate immunity is comprise of what kind of responses to pathogens?
Nonspecific
Innate immunity includes what two things?
1) External barriers
2) Internal cellular and chemical defenses
Acquired immunity
Develops after exposure to microbes, toxins, and other foreign bodies
Acquired immunity is comprised of what kind of response to pathogens?
Specific
This means that specific pathogens are targeted
Barrier defenses of innate immunity
1) Skin
2) Mucous membranes
3) Secretions
Internal defenses of innate immunity
1) Phagocytic cells
2) Antimicrobial proteins
3) Inflammatory response
4) Natural killer cells
Innate immunity recognize what traits?
Traits shared by broad ranges of pathogens, using a small set of receptors
Is innate or acquired immunity faster?
Innate
Humoral response of acquired immunity
Antibodies defend against infection in body fluids
Cell-mediated response of acquired immunity
Cytotoxic lymphoctyes defend against infection in body cells
Most invertebrate recognize what two tissues?
1) Self
2) Nonself
Innate immunity of invertebrates includes:
1) Cuticle of the exoskeleton
2) Phagocytosis and lysosomes
3) Encapsulation
4) Antimicrobial peptides that interfere with microbe signaling or perforate cell walls
What is present in almost all single-celled and multicellular organisms?
Phagocytosis
Lysosomes contain what?
1) Digestive enzymes
2) Cellular toxins (hydrogen peroxide and nitric acid)
Four nonspecific (innate) immune defenses in vertebrates include:
1) Skin and mucus membranes of the respiratory, urinary, and reproductive tracts act as mechanical barriers
2) Saliva and tears contain lysosomes
3) Low pH of skin and digestive system
4) White blood cells that engulf pathogens in the body
Seven blood cell types
1) Mast cells
2) Macrophages
3) Plasma B cell
4) Memory B cell
5) Natural killer cell
6) Helper T cell
7) Cytotoxic T cell
What five blood cells are also lymphocytes (white blood cells)?
1) Plasma B cell
2) Memory B cell
3) Natural killer cell
4) Helper T cell
5) Cytotoxic cell
Macrophages consume what?
1) Pathogens
2) Dead cells
Macrophages are involved in what?
1) Tissue repair
2) Stimulation of lymphocytes
Lymphatic system serves what two purposes?
1) Collect interstitial fluid and returns it to circulation
2) `Transports and houses immune cells
B and T cells have binding sites that do what?
Bind specific antigens
Antigens
Foreign molecules
Lymphocytes have what kind of response to antigens?
An immune response
B cells secrete what?
Antibodies
Antibodies
Free molecules with antigen binding sites
Antibodies serve what purposes in the immune system?
They are signals and binding sites for other components of the immune system
Can antibodies disable pathogens?
Yes
Major histocompatibility complex
Proteins embedded in the surface of the body’s cells and bind to and display proteins
What attracts natural killer cells and T cells?
MHC proteins that bind to and display foreign proteins
Cytokines
Protein hormones involved in communication within the immune system
Cytokines are released by most cells of the body including what?
1) Helper T cells
2) Mast cells
3) Macrophages
Cytokines initiate what?
The inflammation response of the immune system
Following injury, mast cells release what?
Cytokines including histamine
Histamine
Increase local blood vessel dilation
Fever
A systemic inflammation response that raises the body’s temperature set-point
What stimulates a B cell to divide rapidly to produce two types of clones itself?
Binding an antigen
Plasma B cells
Short lived, but immediately active
Memory B Cells
Long lived
Vaccination
A nonpathogenic form of a microbe or part of a microbe is introduced into the body to stimulate active immunity
How is passive immunity acquired?
1) When antibodies cross the placenta from mother to fetus
2) When antibodies are passed to the infant in breast milk
3) When antibodies are injected into the body
