-
innate immunity
- –Found in all animals
- –Responds immediately whether the body has been exposed to the pathogen previously or not
- –Small set of receptors detect a large array of microbes
-
acquired immunity
- –Only in vertebrates
- –Large set of receptors allow specific targeting of pathogens
-
invertebrate innate immunity
- Chitin based exoskeleton provides a first line of defense
- hemocytes
- Other hemocytes trigger the production of antimicrobial peptides
- –Peptides disrupt the plasmamembranes of the bacteriaand fungi
-
hemocytes
are phagocytic cells that digest foreign bodies
-
antimicrobal peptides
- Recognition proteins bind to specific molecules on the cell walls of fungi or bacteria
- The recognition protein activates the Toll protein on the surface of immune response cells
- Signal transduction from Toll to the nucleus causes the synthesis of antimicrobial proteins
-
Vertebrate immunity
- Like invertebrates, vertebrates have innate defenses including barrier defenses, phagocytosis, antimicrobial peptides
- Additional defenses are unique to vertebrates: the inflammatory response and natural killer cells
-
what are the 5 barrier defenses vertebrates have?
- Skin–Blocks many pathogens
- Mucus–Traps pathogens
- Saliva
- Tears
- Lysozyme–Found in tears, saliva and mucus
- –Dissolves bacterial walls
-
what does a WBC do
A white blood cell engulfs a microbe, then fuses with a lysosome to destroy the microbe
-
neutrophils
engulf and destroy microbes
-
macrophages
- are part of the lymphatic system and are found throughout the body
- big eaters
-
Eosinophils
discharge destructive enzymes
-
Dendritic cells
stimulate development of acquired immunity
-
mast cells release?
histamine following an injury which promotes changes in blood vessels; this is part of the inflammatory response
-
during the inflammatory response, These changes increase local blood supply and allow more what and what proteins to enter tissues
phagocytes and antimicrobial protiens
-
pus
a fluid rich in white blood cells, dead microbes, and cell debris, accumulates at the site of inflammation
-
-
lymphocytes
White blood cells called lymphocytes recognize and respond to antigens, foreign molecules
-
T cells vs B cells
Lymphocytes that mature in the thymus above the heart are called T cells, and those that mature in bone marrow are called B cells
-
antigen
is any foreign molecule to which a lymphocyte responds
-
B and T cells
- B cells and T cells have receptor proteins that can bind to foreign molecules
- Each individual lymphocyte is specialized to recognize a specific type of molecule
- A single B cell or T cell has about 100,000 identical antigen receptors
-
B cells give rise to what kind of cells
plasma cells which secrete proteins called antibodies or immunoglobulins
-
epitope
All antigen receptors on a single lymphocyte recognize the same epitope, or antigenic determinant, on an antigen
-
what are the 2 branches of acquired immunity
the humoral immune response and the cell-mediated immune response
-
Humoral immune response
involves activation and clonal selection of B cells, resulting in production of secreted antibodies
-
cell-mediated immune response
involves activation and clonal selection of cytotoxic T cells•Helper T cells aid both responses
-
neutralization
occurs when a pathogen can no longer infect a host because it is bound to an antibody
-
oposonization
- occurs when antibodies bound to antigens increase phagocytosis
- Antibodies together with proteins of the complement system generate a membrane attack complex and cell lysis
-
active immunity
- develops naturally in response to an infection
- It can also develop following immunization, also called vaccination
- In immunization, a nonpathogenic form of a microbe or part of a microbe elicits an immune response to an immunological memory
-
passive immunity
- provides immediate, short-term protection
- It is conferred naturally when IgG crosses the placenta from mother to fetus or when IgA passes from mother to infant in breast milk
- It can be conferred artificially by injecting antibodies into a non-immune person
-
what on a RBC determines a persons blood type?
- antigens on red blood cells determine whether a person has blood type A (A antigen), B (B antigen), AB (both A and B antigens), or O (neither antigen)
- Antibodies to nonself blood types exist in the body
- Transfusion with incompatible blood leads to destruction of the transfused cells
- Recipient-donor combinations can be fatal or safe
|
|
