Defense Mechanisms & Immune Response
where is the bursa of Fabricus located and what is its major function
*only in birds, located just above the cloaca; maturation and differentiation sire for B-cells
list the 4 populations of lymphocytes
1 (regulate immune response) 2 (destroy endogenous antigens) 3 (control immune response) 4 (produce antibodies to destroy exogenous antigens)
what role do macrophages play in wound healing
1 act as phagocytes and kill microorganisms by lysosomal enzymes 2 secrete proteases that breakdown connective tissue 3 source of growth factors for fibroblasts to stimulate them to secrete collagen 4 secrete molecules that promote the growth of new blood vessels
what are the 4 basic requirements of the immune response
1 cells that trap and process the antigen 2 cells that respond to the antigen presenting cells 3 cells that produce antibodies or will participate in the cell mediated response 4 cells that retain a memory for future encounters with antigens
what are the 4 stages of phagocytosis
1 chemotaxis (leave blood bc of attractiveness to chemicals released by other cells in area of inflammation) 2 adherence & opsonization (opsonins lets neutrophil bind to antigen, promotes phagocytosis) 3 ingestion (engulf into vacuole) 4 digestion (destruction)
what role does the mehanical (physical) barrier play in the immune system
1st line of defense: generalized and nonspecific mechanism that blocks the entry of bacteria
briefly describe the 1st, 2nd and 3rd lines of the defense machanism
1st- physical barrier (blocks entry of bacteria) 2nd- focused responses (nonspecific process, neutrophils and macrophages engulf and destroy bacteria) 3rd- specific immunity (protection by stimulating a specific response following exposure to a unique foreign material)
where is the thymus located and what is its major function
anterior mediastinum; source of many of the circulating blood lymphocytes and responsible for the cell-mediated immune responses
what is normal flora
bacteria normally residing in your body
what is the purpose of the immune system
bodys major defense system
from late gestation through adulthood, where are lymphocytes produced
bone marrow
what is the main function of neutrophils
capture and destroy foreign material through phagocytosis
differentiate between a macrophage and a monocyte
immature macrophages are monocytes
what is the thoracic duct
largest lymphatic vessel
what role do lysosomes play in phagocytosis
lysosomal enzymes are the 2nd mechanism of action in the destruction of the foreign material
what is the principle component of the mononuclear-phagocytic sytem
macrophages
what is the definition of a primary lymphoid organ
organ that regulates the production and differentiation of lymphocytes
what is the main function of macropahges
phagocytosis
what is the main function of secondary lymphoid organs
rich in macrophages that trap and process antigens & T and B cells which mediate the immune response
where is the peyer's patch located and what is its major function
ruminant intestine (jejenum & ileocecal junction); site of B-cell proliferation
lymphocytes are immunocompetent cells, what does that mean
they have a special function to recognize and react to antigens
describe the function of lymph nodes
to trap antigen being carried through the lymph
what is a myeloma
tumor of plasma cells
what properties of the: GIT, genitourinary, respiratory tract, mammary gland allow it to be a very effective barrier?
•GIT- oral cavity contains bacteria, lysozymes keep bacteria in check, stomach has acid (low pH) •genitou- low pH, mucous •resp- turbinates trap particles, ciliated epithelial cells, macrophages in airway •mamm- keratinized squamous epithelium (physical barrier)
what are the 2 main categories of lymphocytes and what is the major characteristic that distinguishes these 2 catergories
•T-cells- mature in the thymus •B-cells- mature in bone marrow
where are the T-cells, plasma cells, and macrophages located within a lymph node
•T-cells- paracortex •plasma cells- medulla •macrophages- medulla
which cells are responsible for cell-mediated immunity? which cells are responsible for humoral immunity?
•cell-mediated- •humoral-
what properties of skin allow it to be a very effective barrier against foreign material? how can microbes gain entry into the body through the skin
•dry, keratinized, intact •injury, excess moisture, penetration
what is the main function of eosinophils? basophils?
•eosinophils- phagocytosis •basophils- provoke inflammation bc their granules contain vasoactive amines
what is the myeloid system? what are the 3 types of cells that are derived from the myeloid system
•granulocytes derived from bone marrow(?) •neutrophils, basophils, eosinophils
what are cytokines? list 4 cytokines secreted by macrophages
•group of proteins that regulate immunity 1 interleukin 1 2 interleukin 2 3 interleukin 12 4 tumor necrosis factor-alpha
differentiate between the two general types of immunity
•nonspecific (organisms resistance to disease)(skin, urination) •specific (body recognizes specific foreign materials) (lymphocytes, macrophages)
describe the general anatomy of the spleen and indicate where T-cells and B-cells are located
•red pulp- red blood cell storage •white pulp- immune functions (composed of lymphoid tissue that surrounds small arteriolar branches •T-cells- periarteriolar lymphoid sheaths •B-cells- follicles