lecture exam 4 Flashcards
what is immunology
study of all biological, chemical and physical events surrounding the function of the immune system. the immune system is all over every organ, tissue and fluids.
what does innate, natural, nonspecific immunity include?
this is the 1st line of defense and it includes any barrier that blocks invasion at the portal of entry (skin and mucosal membranes), chemicals, cellular and protective cells and fluids.
what does the second line of defense include?
phagocytosis, complement, and inflammation
what are some physical defenses?
cellular barriers, mechanical defenses and microbiome
acquired, adaptive, or specific immunity includes:
this is the 3rd line of defense. it includes exposure to foreign substance and production of protective antibodies and memory cells
cellular barriers come in 3 different ways. explain them
skin barrier- great barrier to prevent entry of most microbes; epidermis, dermis, hypodermis; infections occur when skin is compromised
mucous membranes- lines the respiratory, urinary and digestive tracts; layer of epithelial cells connected by tight junctions and covered by a layer of mucus; mucus traps microbes, contain antimicrobial peptides
endothelium- epithelial cells that line the blood vessels and lymphatic vessels; effective; blood-brain barrier protects CNS
describe mechanical defenses
goal is to remove pathogens from body before they take up residence in the body; shedding of skin cells, sweat, mucociliary escalator (respiratory tract), going #1 &2, peristalsis (muscle contractions remove sloughed mucus/trapped microbes), sneezing/cough, blinking
describe microbiome
resident microbiota compete for space/nutrition in the skin/upper respiratory tract, GI tract, GU tract with invading pathogens
some produce microbial antagonism- prevents pathogens from growing
chemical defenses include
chemical and enzymatic mediators, plasma protein mediators, cytokines and inflammation- eliciting mediators
what is a chemical defense that is produced by the skin and how does it provide protection against pathogens
oil (sebum)- produced by sebaceous glands
seals off hair follicles and prevents bacteria from invading sweat glands and tissues
name the digestive tract’s chemical and enzymatic mediators found in bodily fluid
oral cavity- saliva contains lactoperoxidase
esophagus- mucous contains lysozyme
stomach- HCI causes high acidity
lower digestive tract- pancreatic/intestinal enzymes, bile, paneth cells produce lysozyme
chemical and enzymatic mediators
urinary tract-
female rep. sys.-
eyes-
ears-
respiratory tract
urinary tract- urine slightly acidic pH 6
female rep. sys.- lactobacillus produces lactic acid to make pH lower (exogenous mediator)
eyes- tears contain lysozyme (acts of peptidoglycan) and lactoferrin (binds iron)
ears-cerumen traps bacteria and contains fatty acids
respiratory tract- contain lysozyme, lactoferrin, lactoperoxidase
proteins that protect the blood against microbes are
complement proteins and cytokines
what is the complement system?
*group of plasma protein mediators that connect the innate and adaptive immunity
*30 proteins (c1-c9)
*activated by microbes, antibodies, mannose-binding lectin by 3 ways
* provide the same protective outcomes- opsonization, inflammation, chemotaxis, and cytolysis
what is the function of the complement system?
*opsonization- coating of pathogen by a chemical substance: allows phagocytic cell to recognize, engulf, and destroy
*include C3b, antibodies, mannose-binding protein
*inflammation is triggered by C5a which calls chemotaxis, neutrophils and macrophages to the area
*cytolysis-MAC composed of C6,C7,C8 &C9; forms pores in membrane of gram-
what is cytokines?
*soluble protein act as communication signals b/w cells
*cause cell proliferation, cell differentiation, inhibition of cell division, apoptosis, and chemotaxis
*bind to target receptor of cell to act as autocrine, paracrine or endocrine fashion
*two most important: interlukins and interferons
desrcibe interlukins (boss lady) and interferons (chismosos)
interlukins- modulates almost every function of the immune system
interferons- produced by cells when infected with viruses and alert immune system that there is a virus infection; stimulates nerby cells to prevent virus replication inside them; stimulate immune system to attack virus infected cells
describe the chemical mediator: inflammation-eliciting meditator
contribute to inflammation/fever
what is histamine
chemical mediators that is released from mast cells and basophils to promote vasodilation, bronchoconstriction, contraction of smooth muscles, increased mucus secretion
what is prostaglandis? what does it cause?
chemical mediators that promotes inflammation and fever
what is Bradykinin and what does it do?
chemical mediator that increases vasodilation and vascular permeability to cause edema
what are cellular defenses?
erythrocytes- carry oxygen
thrombocytes- clot formation/platelets
leukocytes- wbc
what is hematopoiesis
formation of blood with formed elements
neutrophils, eosinophils, basophils, or mast cells are_____
granulocytes
B lymphocytes and T lymphocytes, natural killer cells, monocytes are_____
agranulocytes
what are neutrophils?
*main role: phagocytosis’ go through walls of blood vessels when “called” for inflammation
*degranulation: defensins and hydrolytic enzymes release toxic molecules to surrounding tissue to kill bacteria
*neutrophil extracellular traps (NETs) form a net to trap pathogens to kill them
what are eosinophils?
*role in phagocytosis
*effective against protozoa and helminths
*allergic reactions
*granules contain histamine
what are basophils?
*involved in inflammation and allergic reaction
*granules contain histamine
*degranulation is activated by complement
what are mast cells?
*functionally similar to basophils
*bound to connective tissue around blood vessels
B & T lymphocytes are involved in ____
specific adaptive immune respomse
whar are Natural Killer cells?
*type of T cells involved in nonspecific innate defenses
*recognize/destroy any abnormal cells
*destroy by secreting
*perforins which creat a pore in the target cell
*granzymes enter pores/triggers cell to die by apoptosis
what are monocytes?
*when they leave the bloodstream, they differentiate into a macrophage/dendritic cell
*macrophages reside in body tissues for long time
*dendritic cells reside in skin and mucous membranes
*major role in phagocytosis
what is phagocytosis? what is the function?
*seek, ingest, kill pathogens
*phagocytes circulate bloodstream/ability to leave squeezing out endothelial cells of capillaries called diapedesis (or extravasation)
*initiated by chemotactic factors: Ca5 & other cytokines released by tissue cells and macrophages
describe phagocytic recognition
*phagocytes recognize pathogen molecular structures called pathogen-associated molecular patters or PAMPs
*using patterns recognition receptors (PRRs), the phagocytes will bind to the PAMPs
*this triggers the phagocyte to engulf the pathogen
what is inflammation?
*triggered by a cascade of chemical mediators and cellular responses that occure when cells are damages/stressed and when pathogens breach teh physical barriers of the innate immune system
*allows recruitment of cellular defenses needed to elimate pathogens, remove damaged and dead cells, initiate repair mechanism
steps of acute inflammation
- vasoconstriction of blood vessels will occur to minimize blood loss
- vasodilation/increased vascular permeability happens due to release of histamine by mast cells; 5 signs: erythema, edema, pain, hear, altered function. this causes…
- influx of phagocytes at site of injury, diapedesis, neutrophils arrive first, phagocytes contribute to inflammatory response, complemetn sysrem is activated, pus forms
- macrophages arrive second to clean up
what is fever
*inflammatory respone
*inhbits multiplication of heat sensitive microbes
*prevents nutrition of bacteria by reducing the availability of iron
*enhances the innate immune defenses
what regulates the body temperature
hypothalamus
primary lymphoid organs
site of lymphocytic origin and maturation
*bone marrow- site of all blood cell formation;site of B-cell maturation
*thymus- high rate of growth & activity until puberty, then begins to skrink; T cell maturation site
secondary lymphoid organs and tissues
spleen and lymph nodes
cells distributed throughout body tissues- skin and mucous membranes
*lymph nodes-small, encapsulated, bean-shaped organs along lymphatic channels/large blood vessels of the thoracic/abdominal cavities
*spleen- similar to lymph node, filters circulating blood to remove worn out RBCs and pathogens; miscellaneous: Peyer’s patch, SALT, MALT, BALT, NALT, tonsils