UNIT 8 - LYMPHATIC AND IMMUNE SYSTEMS Flashcards
1
Q
why do we need an immune system?
A
-defense against infections + tumors
2
Q
what happens if the immune system does not work correctly?
A
-self cells can become injured
-inflammation can be induced
3
Q
what are the good characteristics of our immune system?
A
-knows when to respond
-responds quickly to all potential pathogens (new and old)
-has an appropriate/effective response
-has memory in some cases
4
Q
what are the aspects of an appropriate/effective immune response?
A
-targets foreign pathogens specifically
-no surrounding injury to self cells
-redundancy (back ups)
-diversity (changes tactics)
-regulation
5
Q
what is an example of immunological memory?
A
-vaccines
-familiarizes the body
-increases memory
-increases repertoire
6
Q
what are the 3 questions the immune system asks before responding?
A
-is it foreign?
-self or non-self
-is it dangerous?
-food is foreign but not dangerous
-clinical challenge?
-organ transplantation
7
Q
what are the two branches of the immune system?
A
-innate immune system
-adaptive immune system
8
Q
what are the functions of the lymphatic system?
A
-lymphatic capillaries absorb excess interstitial fluid and return it to the bloodstream
-lacteals (special lymph capillaries) in the small intestine absorb fats and transport them to the bloodstream
-helps in pathogen defense
-produces, maintains, and distributes lymphocytes in the body
9
Q
what does the lymphatic system consist of?
A
-lymphatic vessels, organs, and fluids
10
Q
what is carried within the lymphatic vessels?
A
-lymph
11
Q
what are the beginning lymphatic vessels?
A
-blind-ended capillaries in tissues
12
Q
what are the 2 lymphatic ducts?
A
-thoracic duct
-right lymphatic duct
13
Q
where does the thoracic duct collect lymph from? where does it empty into?
A
-below the thorax (chest), left arm, left side of head and neck
-left subclavian vein
14
Q
where does the right lymphatic duct collect lymph from? where does it empty into?
A
-the right arm, right side of head and neck
-right subclavian vein
15
Q
how are the larger lymphatic vessels similar to veins?
A
-contain valves to prevent lymph from flowing backwards
16
Q
what does the movement of lymph depend on?
A
-muscle contraction
17
Q
what are the primary lymphoid organs?
A
-red bone marrow
-thymus
18
Q
what are the secondary lymphoid organs?
A
-lymph nodes
-lymphatic nodules
-spleen
-tonsils
-peyers patches
19
Q
what is the red bone marrow?
A
-site of blood cell production (produces 200 million daily)
-site of B lymphocyte maturation
20
Q
what is the difference in red bone marrow in children and adults?
A
-most bones in children have red bone marrow
-only a few do in adults
-half of it is converted into yellow bone marrow by age seven
21
Q
how much does red bone marrow weigh in adults?
A
-2.7Kg
22
Q
what happens to the yellow bone marrow during emergencies?
A
-body converts yellow bone marrow to red
-to help keep you alive
23
Q
what is the thymus?
A
-bilobed organ (2 lobes)
-produces thymosin
-site of T lymphocyte maturation (move from the red bone marrow)
24
Q
what is the function of thymosin?
A
-induces T lymphocyte maturation
25
where is the thymus located?
-in the thoracic cavity
-superior to the heart
26
what happens to the thymus as you age?
-shrinks
-largest in children
27
where are the lymph nodes found? what areas are they commonly within? what is their purpose?
-along lymphatic vessels
-neck, armpit, and groin
-filter lymph
28
what are contained within lymph nodes? what divides the lymph node into compartments?
-macrophages that engulf pathogens and debris (innate)
-lymphocytes to fight infections and cancer cells (adaptive)
-CT forms a capsule around it and divides it
29
how are lymph nodes named?
-for their location
30
what are lymphatic nodules?
-concentrations of lymphoid tissue
-do not have a capsule (differ from nodes)
31
where are the tonsils located?
-the pharynx
32
what is the function of tonsils?
-fight infections that come through the nose and mouth
33
where are peyer's patches found?
-in the intestinal walls and the appendix
34
what is the function of peyer's patches?
-fight infections that come through the digestive tract
35
where is the spleen located?
-upper left region of the abdominal cavity
36
what is the function of the spleen?
-filter blood for pathogens
-removes dead/end of life blood cells
-percolation
37
what divides the spleen? what does it divide into?
-CT divides it into white pulp and red pulp
38
what is contained within white pulp?
-macrophages
-removes pathogens, debris, worn-out red blood cells
39
what is contained within red pulp?
-lymphocytes
-interact with antigens and antigen presenting cells
40
what surrounds the spleen? what make occur?
-a thin outer capsule
-could rupture from trauma
41
what is the basis of the innate immune system?
-fully functional without previous exposure to a pathogen
-no memory
42
what is the basis of the adaptive immune system?
-initiated when exposed to a pathogen
-typically the innate immune system that exposes the pathogen
43
what are the main assets of the innate immune system?
-recognizes pathogens based on danger signals
-rapid responder (minutes-hours)
-diverse and intense
-helps generate an adaptive immune response when needed (calls immune cells to the site of infection and programs them with functions)
44
what are the main downfalls of the innate immune system?
-no adaptability (ex: new variants that may evolve to resist innate immunity)
-no memory (same speed, type, and intensity for the 1st exposure or 10th exposure)
45
what is the main goal of the innate immune system?
-contain the pathogen in the initial hours and days of infection
-gives time for a sophisticated, diverse, and specific defense to be deployed (adaptive immune system)
46
how does the innate immune system work with the adaptive immune system?
-directs the type of specific immune response
-instructs the adaptive immune system
47
what are the types of defenses within the innate immune system?
-physical and chemical barriers
-cells and inflammatory response
-protective proteins "complement"
48
what is an example of a physical barrier?
-epithelial linings of the airway, GI tract, etc
-covers all exposed body surfaces (inside and out)
49
what systems have epithelial linings located within the internal cavities?
-digestive system
-respiratory system
-cardiovascular system
-genitourinary system (urinary and reproductive)
50
what is an example of an outer epithelial lining? how does it act for the innate immune system?
-skin
-has lots of keratin (tough)
-exfoliation of the skin will carry microbes away from the body
51
what is an example of something within the intestinal epithelium that provides protection against microbes?
-paneth cells
-produce antimicrobial peptides and lectins
52
what is an example of something within the respiratory system that acts as a barrier within the epithelium?
-goblet cells in the epithelial lining secrete mucus
-traps particles larger than 2 micrometers
-have cilia to sweep away mucus with pathogens entrapped
53
what is the "mucociliary escalator"?
-removes pathogens away from the respiratory tract
-cilia propel mucus upward in the bronchi to eliminate microorganisms
54
what can slow the mucociliary escalator?
-anesthetics
-air pollutants
-tobacco smoke
-some viral and bacterial infections
55
what are examples of chemical barriers?
-low pH in the gastrointestinal tract and vagina
-acidic pH of the stomach
-sebum
-acidic secretions from sebaceous glands
-lysozyme in tears and saliva
-normal flora
56
how does the low pH in the gastrointestinal tract and vagina work as a chemical barrier?
-works along with normal flora
-prevents infection of potentially dangerous microbes
57
how does the acidic pH of the stomach work as a chemical barrier?
-inhibits or kills bacteria
58
how does sebum work as a chemical barrier?
-creates an undesirable environment for pathogens
59
how do acidic secretions of the sebaceous glands work as a chemical barrier?
-weaken and kill bacteria on the skin
60
what is lysozyme?
-antibacterial product in tears and saliva
-protective
61
what is normal flora? how does normal flora work as a chemical barrier?
-microbes (typically within the mouth and intestine) (good bacteria)
-prevents potential pathogens from residence
62
what can chronic use of antibiotics cause?
-can become susceptible to infection by killing off normal flora
63
what are the cells within the innate immune system?
-employs neutrophils, macrophages, and dendritic cells to engulf pathogens (antigen-presenting cells)
64
what is a response/process within the innate immune system?
-inflammatory response
65
what is the basis of the inflammatory response?
-response of vascularized tissues to infections and damaged tissues
-brings cells and molecules from circulation to the infection site to eliminate offending agents
-protective response
66
how does the innate immune system recognize pathogens?
-can recognize families of antigens
-known as P/MAMPS (pathogen/microbe associated molecular patterns)
-patterns shared by various classes of pathogens
-patterns are not normally present on self cells
67
what is a pro of the innate immune systems strategy for recognizing pathogens?
-less than 1000 microbial patterns
68
what is a con of the innate immune systems strategy for recognizing pathogens?
-lymphocytes within the adaptive immune system express receptors for a billion different antigens
-more widespread and specific
69
what are the cardinal signs of the inflammatory response?
-heat
-pain
-redness
-swelling
70
what are the 3 components of acute inflammation?
-dilation of small vessels to increase blood flow
-increased microvasculature permeability (plasma proteins and WBC to leave circulation)
-migration of leukocytes from the microcirculation (accumulate in the focus of injury + activation to eliminate the offending agent)
71
what are the responses of the inflammatory response?
-chemicals like histamine are released by damaged tissue cells and mast cells (capillaries dilate and are more permeable and more blood flow)
-increased permeability = fluids and proteins escape into tissues
-excess fluid in tissues (swelling) presses on nerve endings (pain)
-excess blood flow causes skin to become red and warm
-increased temp inhibits the growth of pathogens
-increased blood flow brings white blood cells to the area
-blood clotting prevents blood loss
72
what are soluble factors?
-produced by various cells or derived from plasma proteins
-generated or activated in response to the inflammatory stimulus
73
what do microbes and necrotic cells trigger? how does this shape the inflammatory response?
-inflammatory mediators
-elicits and amplifies the inflammation
-determines its pattern, severity, and clinical and pathologic manifestations
74
what are cytokines?
-proteins produced by many cell types (lymphocytes, macrophages, dendritic cells, endothelial, epithelial, connective tissue cells)
-induce local and systemic effects
-ex: interferons, interleukin, and TNF
75
what is the purpose of interferons?
-proteins produced by cells that are infected with viruses
-act as a warning
-bind to receptors of noninfected cells causing them to produce substances that interfere with viral replication
76
what is the purpose of interleukin and TNF?
-mediate and regulate immune and inflammatory reactions
77
what are the 4 steps to the inflammatory response?
-injured tissue cells and mast cells release histamine causing capillaries to dilate and increase blood flow
-neutrophils first phagocytize pathogens to localize the infection and prevent spread, if overwhelmed they release cytokines to attract more WBCs
-antigen presenting cells will capture and present the antigen to B and T cells
-monocytes come to the area after and become macrophages
-blood clotting walls off the capillary and prevents blood loss
78
what are examples of antigen-presenting cells? what do they do?
-macrophages
-dendritic cells
-capture and present the antigen to B and T cells
79
what is the complement system?
-collection of soluble proteins and membrane receptors
-designated by the letter C and a #
-function mainly in host defense against microbes and pathologic inflammatory reactions
-amplify the inflammatory response
-bind to mast cells (trigger histamine release)
-attract phagocytes to the infection site
-form a membrane attack complex to produce holes in bacterias surface (fluids enter the cells and burst)
80
which complement protein cleavages?
-C3
-into C3a and C3b
81
when does the adaptive immune system come into play?
-when innate defenses have failed to prevent an infection
82
what can be considered antigens?
-abnormal plasma proteins produced by cancer cells
-parasitic worms
-bacteria
-viruses
-molds
83
what does the adaptive immune system depend on?
-the action of B cells and T cells
84
what are found on B cells and T cells?
-specific antigen receptors
-each has only one type of receptor
-receptor and antigen fit together
85
how can an antigen be presented to the receptor?
-by a cell
-detected within fluid
86
what are the 2 pathways of adaptive immunity?
-cell mediated immunity
-antibody mediated immunity
87
how does cell-mediated immunity work?
-T cells kill cells that present a specific foreign antigen
88
how does antibody-mediated immunity work?
-B cells produce antibodies that bind to free antigens in body fluids
89
what is the basic structure of an antibody?
-Y shaped protein with 2 arms
-2 chains per arm
-can be single molecules (monomers) or paired in dimers, or pentamers (5 molecules)
-joining section is the J chain
90
what are the 2 chains that make each antibody arm? what is found on each type of chain?
-heavy/long polypeptide chain
-light/short polypeptide chain
-constant region
-variable region
91
what is the constant region?
-at the trunk of the Y-shape
-where the sequence of amino acids is fixed
-its structure classifies antibodies
92
what is the variable region?
-forms the antigen binding site
-shape is specific to each antigen
93
what is the process of neutralization?
-antibodies coat viruses and toxins
-neutralizes them and removing the threat
94
what is an immune complex?
-a clump of antigens combined with antibodies
95
what are the 5 classes of circulating antibodies?
-IgG
-IgM
-IgA
-IgD
-IgE
96
where is the IgA class of antibodies found?
-in secretions such as saliva and breast milk
-present at the mucosa level
97
what is the function of the IgA class of antibodies?
-prevents pathogens from attaching to epithelial cells in digestive and respiratory tracts
98
where is the IgD class of antibodies found?
-on the surface of immature B cells
99
what is the function of the IgD class of antibodies?
-signifies readiness of a B cell
100
where is the IgE class of antibodies found?
-antigen receptor on mast cells in tissues
101
what is the function of the IgE class of antibodies?
-immediate allergic response
-protection against certain parasitic worms
102
where is the IgG class of antibodies found?
-in circulation
-crosses the placenta from mother to fetus
103
what is the function of the IgG class of antibodies?
-binds to pathogens
-activates the protein complement
-enhances phagocytosis by WBCs
104
where is the IgM class of antibodies found? what is special about it?
-in circulation
-largest antibody
-first antibody formed by a newborn
-first antibody formed with any new infection
-first antibody to disappear when the infection is over
105
what is the function of the IgM class of antibodies?
-activates the protein complement
-clumps cells
106
what are monoclonal antibodies?
-can be produced in the lab and used for medical tests and treatments
-produced by a single plasma cell derived from the same B cell
-they will be identical
107
what occurs if neutrophils die off in significant quantaties?
-become a yellow-white substance called pus
108
what are B-cell receptors (BCR)? what binds to them?
-protein receptors on B cells
-antigens (only one type per type of B cell)
109
what occurs when an antigen binds to the BCR?
-the B cell will produce copies of itself
-group of identical B cells is called a clone
-all cells will have the same specificity
110
what is clonal expansion within an antibody mediated response?
-cytokines are secreted by helper T cells to stimulate B cells to clone
-the B cell with the activated BCR produces plasma cells (most) and memory B cells
111
what is the purpose of plasma cells within an antibody mediated response?
-produce large numbers of antibodies that bind to the antigen that initiated the clonal expansion process
112
what is the purpose of memory B cells within an antibody mediated response?
-will become active in future encounters with the same antigen
113
what occurs after an infection has been overcome in an antibody mediated response?
-plasma cells are not needed
-they undergo apoptosis (programmed cell death)
114
what are T cell receptors (TCR)? how do they differ from BCR?
-unique receptors on the surface of T cells
-cannot recognize antigens on their own
-must be displayed to them by an antigen presenting cell (APC)
115
how do APCs present an antigen to a T cell?
-the pathogen is phagocytized and broken apart
-a piece of the pathogen is displayed in the groove of a major histocompatibility complex (MHC) protein on the cells surface
-then travel to T cells in a lymph node or the spleen
116
what are the 2 classes of MHC proteins?
-MHC I
-MHC II
117
what are human MHC II proteins called? where are they found?
-human leukocyte antigens (HLAs)
-in all body cells
118
what are the 3 general groups of HLAs?
-HLA-A
-HLA-B
HLA-DR
-several protein variations
-each person's combo of HLAs is unique (twins have the same)
119
what is clonal expansion within a cell mediated response?
-when APCs present an antigen to a T cell with the specific TCR it binds
-this activates the T cell and starts clonal expansion
-copies of the activated T cell are produced
-some become cytotoxic T cells
-some become helper T cells
120
what are cytotoxic T cells?
-activated after recognition of an antigen presented by MHC I
-has storage vacuoles containing perforins and enzymes called granzymes
121
what response do cytotoxic T cells have in response to binding with an infected cell?
-binding will initiate the release of perforins
-punches holes in the plasma membrane (forming a pore)
-granzymes are then delivered to the pore (cell undergoes apoptosis)
122
what are T helper cells?
-activated after recognition of an antigen presented by MHC II
-secrete cytokines to enhance the response of all types of immune cells
-most B cells cannot be activated without them
123
what virus infects T helper cells? what does this cause?
-HIV (human immunodeficiency virus) (causes aids)
-causes the immune response to be inactivated
124
how do cells and tissues of the immune system stay in contact?
-cells come into contact and surface molecules interact (triggers intracellular pathways)
-cytokines are secreted to communicate in paracrine (sometimes autocrine) manners
-chemokines
-certain cells produce specific cytokines and chemokines
-certain cells express specific receptors for them
125
what are chemokines?
-proteins that help immune cells get where they need to go
-also have other biological functions
126
what brings acquired immunity? what are the 2 types of acquired immunity?
-naturally through infection
-artificially through medical intervention
-active and passive
127
what is active immunity?
-individuals body makes antibodies against a particular antigen
-occurs through natural infection (measles) or through immunization involving vaccines (mimics a natural infection)
128
what is contained within a vaccine?
-antigens from the pathogen
-treated so they can no longer cause disease
129
what are the 2 exposures to an antigen?
-first exposure = primary response
-second exposure = secondary response
130
what does active immunity depend on?
-memory B and T cells
-booster shots (in case of vaccines)
131
what is passive immunity?
-an individual is given antibodies to combat a disease
-not produced by the individuals plasma cells = temporary
132
what are some examples of passive immunity?
-newborn infants are passively immune to some diseases because IgG antibodies have crossed the placenta from the mother's blood and are also secreted into breast milk
-antibodies injection
133
what are abnormal hyper-reactions?
-when the immune system overreacts and causes harm to the body
134
what does it mean to be sensitized?
-previously being exposed to an antigen manifests detectable reactions to that antigen
-memory of the immune system allows for a more effective response
-the body is primed to react to that antigen
135
what is hypersensitvity?
-an excessive or harmful reaction to a specific antigen
-can even be allergens that would usually be harmless
136
what is an immediate allergic response? what causes it?
-occurs within seconds of contact with the antigen
-caused by IgE antibodies attaches to receptors on mast cells and basophils (release histamine when they bind to allergens)
-food allergies experience nausea, vomiting, and diarrhea
137
how does histamine affect the body in allergic responses?
-affects mucous membranes and airways
-when pollen is the allergen, histamine causes mucous membranes of the nose and eyes to release fluid (hay fever)
-with asthma airways constrict and wheezing occurs
138
what is anaphylactic shock?
-an immediate allergic response
-occurs when the allergen enters the bloodstream
-sudden drop in blood pressure due to increased permeability of capillaries by histamine
-epinephrine counteracts this reaction
139
what are delayed allergic responses?
-initiated by memory T cells at the location of contact with the allergen
-ex: poison ivy or previous immune response (tuberculosis)
140
what occurs within a tissue rejection?
-rejection of a transplanted tissue (body recognizes it as not self)
-cytotoxic T cells attack the transplanted tissue
141
how can a tissue transplant be controlled to prevent rejection?
-with immunosuppressive drugs
-by transplanting organs with the same MHC proteins in the donor and recipient
142
how do immunosuppressive drugs act?
-inhibit the production of cytokines
-down regulates the entire immune system
143
how does immunodeficiency arise?
-combo of the following
-inheritance of susceptibility genes (HLA gene or non-HLA gene)
-environmental triggers, infections, and tissue damage (promote activation of self-reactive lymphocytes)
144
what are two kinds of immunodeficiency?
-congenital
-aquired
145
what is an example of a congenital immune deficiency?
-severe combined immunodeficiency disease
-both antibody and cell mediated immunity are inadequate or lacking
-minor infection can be fatal
-treated with bone marrow transplant or gene therapy
146
what causes acquired immune deficiencies?
-infections
-chemical exposure
-radiation
147
what is an example of a acquired immune deficiency?
-acquired immunodeficiency syndrome (AIDS)
-results from infection with the human immunodeficiency virus (HIV)
-infects T helper cells
-become more susceptible to infections and have a higher risk of cancer and other diseases
148
what is an autoimmune disease?
-cells of the immune system (cytotoxic T cells or antibodies) attack the body's own cells as if they are foreign
-involve both genetic and environmental factors
-sometimes follows an infection
149
what are examples of autoimmune diseases?
-rheumatic fever
-rheumatoid arthritis
-systemic lupus erythematosus (SLE)
-multiple sclerosis
150
what is rheumatic fever?
-antibodies induced by a streptococcal bacterial infection of the throat also react with the heart muscle
-damages the heart muscle and valves
151
what is rheumatoid arthritis?
-antibodies against joints (hand, wrist, knee)
152
what is systemic lupus erythematosus (SLE)?
-produce high levels of anti-DNA antibodies
-all human cells (except RBC) contain DNA (symptoms can be seen throughout the whole body)
-symptoms include facial rash, fever, joint pain
-damage to the CNS, heart, and kidneys can be fatal
153
what is multiple sclerosis?
-T cells attack the myelin sheath covering nerve fibers
-causes the CNS to dysfunction (brain and body communication issues)
-double vision and muscular weakness
-may not be autoimmune because a specific antigen has not been identified
154
what are drug treatments for autoimmune diseases designed to decrease?
-the immune response
