Blood And Immune Flashcards
1
Q
What is the average volume of blood in women?
A
5L
2
Q
What is the average volume of blood in men?
A
5.5L
3
Q
What percentage of the total body weight is blood?
A
8%
4
Q
What are the three cellular components suspended in plasma?
A
Erythrocytes
Leukocytes
Thrombocytes
5
Q
What is the common name for erythrocytes?
A
Red blood cells
6
Q
What percentage of blood is red blood cells?
A
99%
7
Q
What is the common name for leukocytes?
A
White blood cells
8
Q
What is the common name for thrombocytes?
A
Platelets
9
Q
What does hematocrit level’s represent?
A
Percentage of red blood cells in the total volume of blood
10
Q
What is the average hematocrit level for females?
A
42%
11
Q
What is the average hematocrit level for males?
A
45%
12
Q
What is the purpose of plasma?
A
Serves as a medium to carry the components within blood
13
Q
Plasma is ____ % water
A
90
14
Q
Describe plasmas role in heat distribution
A
Plasma has a high capacity to hold heat and therefor is used to distribute heat throughout the body
15
Q
What are the inorganic substances associated with plasma?
A
Electrolytes (Na, Cl, K, H2CO3)
16
Q
What is the purpose of electrolytes in plasma?
A
Regulate membrane excitability, osmotic distribution between ECF and cells and pH buffering
17
Q
What are the organic substances associated with plasma?
A
Plasma proteins
Glucose
Amino acids
Lipids
Vitamins
Creatine
Bilirubin
Hormones
Gases
18
Q
What is serum?
A
The part of the blood which is similar to plasma in composition but lacks clotting factors
19
Q
What are clotting factors?
A
Allows blood to clot specifically in times of injury
20
Q
The ECF is composed of what fluids?
A
ISF and plasma
21
Q
Where are plasma proteins primarily synthesized?
A
The liver
22
Q
What specific plasma protein is NOT synthesized in the liver?
A
Gamma globulins aka antibodies
23
Q
What is the purpose of plasma proteins?
A
Establish an osmotic gradient between blood and ISF and prevents excess loss of plasma from capillaries into the ISF and maintains plasma volume
24
Q
What are the 3 groups of plasma proteins?
A
Albumins
Globulins
Fibrinogen
25
What is the purpose of albumins?
Contributes to colloid osmotic pressure
Non-specifically binds to many substances that are poorly soluble in plasma to aid in their transport
26
Which of the three plasma proteins are most abundant?
Albumins
27
How many types of globulins are there?
3
28
What is the purpose of globulins?
Highly specific
Carry poorly soluble substances
Carry substances involved in blood clotting cascade, activation of other proteins and those important in host defence
29
What is the purpose of fibrinogen?
Key factor in the blood clotting cascade
30
Describe what happens in the arterial end of the capillary
Filtration
Has a net filtration pressure of +10 mmHg
Fluid exits the capillary because rage capillary hydrostatic pressure (35mmHg) is greater than bloods colloid osmotic pressure (25mmHg)
31
Describe what happens in mid capillary
There is no net movement of blood
Net filtration pressure is 0 mmHg
Capillary hydrostatic pressure and blood colloid osmotic pressure are equal at 25mmHg
32
Describe what happens in the venous end of the capillary
Reabsorption
Net filtration pressure is -7mmHg
Fluid renters the capillary because capillary hydrostatic pressure (17mmHg) is less that blood colloid osmotic pressure (25mmHg)
33
What is the shape of normal red blood cells?
Flat
Indented
Disc shaped
34
Why is a ref blood cell concave in the center?
Provides a larger surface area for diffusion of oxygen across the membrane
35
What is the benefit of thinness for a red blood cell?
Enables oxygen to diffuse rapidly between the exterior and innermost region of the cell
36
Why is it beneficial for red blood cells to lack a nucleus?
Allows it to carry more oxygen
37
Do red blood cells carry genetic material?
No
38
Why are the membranes of red blood cells flexible and pliable?
To squeeze through tight spaces
39
What is the most important feature of a red blood cell that allows them to carry oxygen?
Contain Hemoglobin
40
What are the 2 parts of haemoglobin?
Globin
Heme
41
What is globin?
A protein consisting of 4 highly folded polypeptide chains
42
What are heme groups?
4 iron containing, non-protein groups that are each bound to a polypeptide
43
Is the action of binding iron to oxygen, reversible or irreversible?
Reversible
44
What percentage of oxygen is carried by harmoglobin?
98.5%
45
In what direction does haemoglobin carry oxygen?
Lungs to tissues
46
What other substances can haemoglobin bind?
CO2, H, CO and NO
47
Why is CO poisoning so easy to get?
Because haemoglobin prefers to bind with CO rather than O2
48
What is the oxygenated state of haemoglobin known as?
R state
49
What is the deoxygenated state of haemoglobin known as?
T state
50
Which state of haemoglobin has a larger water cavity, T or R?
T state
51
Why are red blood cells anucleated?
During their development, intracellular components are extruded
52
What is the average life span of a red blood cell?
120 days
53
What are 2 non-renewable enzymes in red blood cells?
Glycolytic enzymes
Carbonic a hydrate
54
Why are glycolytic enzymes important?
To generate energy needed to fuel active transport mechanisms involving the maintenance of ideal intracellular ion concentrations (solely rely on glycolysis due to no mitochondria)
55
Why are carbonic anhydrase’s important in red blood cells?
Critical for CO2 transport and catalyze the reaction from CO2 to hydrogen carbonate (HCO3)
56
What happens to a red blood cell as it gets old?
It becomes fragile and ends up in the spleen
57
How many developmental waves of erythropoiesis are there in mammals?
3
58
What describes the first wave of erythropoiesis?
Emergence of primitive erythroblasts that express embryonic Globins in yolk sac blood islands
59
What describes the second wave of erythropoiesis?
The erythro-myeloid progenitor emerges from the yolk sac and migrated to the fetal liver, producing definitive erythroblasts expressing predominantly mouse adult Globins.
60
What describes the third wave of erythropoiesis?
The haematopoietic stem cell emerges from the haemogenic endothelium in the aorto-gonad mesonephrons and other sites. The HSC migrates to the fetal liver and eventually into the adult bone marrow, producing definitive erythroblasts
61
What is erythropoietin?
A hormone that stimulates erythropoiesis in the bone marrow
62
How is erythropoietin secretion stimulated?
Reduced oxygen delivery to the kidney
63
Recombinant erythropoietin is used to treat _____
Anemia
64
Are the antigens located inside or on the outside of red blood cells?
On the surface
65
What is the name of the most common blood typing system?
ABO
66
What are the 4 blood types? (Basic)
A
B
AB
O
67
What are the 4 possible antigen types?
A antigen
B antigen
AB antigen
Neither A or B
68
When do antibodies against not present antigens begin developing?
Around 6 months
69
Type A blood contains anti ___ bodies
B
70
Types B blood contains anti ___ bodies
A
71
Type AB blood contains ___ antibodies
No
72
Type O contains ____ antibodies
Both
73
At an early get we are exposed to small amounts of A and B like antigens associated with ____
intestinal bacteria
74
What is agglutination?
She. Your blood reacts with an antibody
75
What is the Rhesus factor?
An erythrocytes antigen first observed in Rhesus monkeys
76
What are the antigen groups for the rhesus factor?
D C E d c e
77
Which rhesus antigen is found most frequently?
D
78
Anti-RhD antibodies are produced only by _____ individuals
Rh negative
79
What is erythroblastosis fetalis?
When a Rh negative mother develops antibodies against the red blood cells of an Rh positive fetus
80
To prevent the breakdown of fetal red blood cells during erythroblastosis fetalis, what is delivered to the mother?
Rho(D) immune globulin
81
What is RhoGam (Rho(D) immune globulin)?
A solution of Ig anti-RhD antibodies that removed any fetal RhD positive erythrocytes in the maternal blood stream
82
What is transfusion reaction?
When blood is transfused to an incompatible type (the recipients plasma attacks the incoming donor erythrocytes)
83
Antibody-antigen binding can result in 2 separate situations, what are they?
Agglutination
Haemolytic
84
what blood type is the universal donor?
O-
85
what blood type is the universal recipient?
AB
86
are Rh- considered universal recipients or donors?
donors
87
what are the 2 major research results for blood substitutes?
- haemoglobin products that exist outside the RBC - haemoglobin-based oxygen carriers
- perfluoreocarbon-based oxygen carriers
88
what is hemopure?
- made of chemically synthesized bovine haemoglobin
- approved in south africa
- FDA allows for product to be used on compassionate grounds
89
what is anemia?
below normal oxygen carrying capicity in the blood characterized by low hematocrit
90
how does anemia arise?
from disease, decreased erythropoeisis, excessive loss of erythrocytes, deficiency in haemoglobin
91
what are the different types of anemia?
nutritional
pernicious
aplastic
renal
haemorrhagic
haemolytic
92
what is nutritional anemia?
caused by dietary deficiency of a factor needed for erythropoiesis
93
what is pernicious anemia?
caused by inability to absorb enough ingested vitamin B12
94
what is aplastic anemia?
failure of bone marrow to produce enough RBCs
95
what is renal anemia?
caused often from kidney disease where the kidney does not make EPO to signal RBC development
96
what is hemorrhagic anemia?
caused by a loss of blood
97
what is haemolytic anemia?
caused by a rupture of RBCS. observed in malaria and sickle cell
98
what is sickle cfell?
a hereditary abnormality in erythrocytes that makes RBCs fragile
affects persons of african descent
rigid, stiff and unnaturaally-shaped RBC
prevents blood flow through small vessels
99
what is the abnormality is sickle cell?
a defective haemoglobin caused by a single nucleotide polymorphism in the beta-globin gene
100
what is polycythaemia?
having too many circulating RBCs and an elevated haematocrit
101
what is primary polycythaemia?
caused by tumor like condition of bone marrow whereby erythropoeisis occurs at an uncontrolled rate
increased RBC results in sluggish blood flow, reduced oxygen delivery, increased BP and workload
increaed white blood cells and platelets
102
what is secondary polycythaemia?
an EPO regulated mechanism that occurs in response ti prolonged reduction of oxygen delivery to tissues
altitude polycythemia
103
what is relative polycythemia?
occurs when there is an elevated haematocrit, but due to a loss in fluid
104
where do leukorcytes arise from?
a common pulripotent stem cell
105
what are leukocytes important for?
recognizing/eliminating pathogens and clearing debris from damaged tissue sites to enable repair mechanisms
106
what are the 5 primary types of leukocytes?
lymphocytes
monocytes
neutrophils
eosinophils
basophils
107
what classes of leukocytes are agranulocytes?
lymphocytes
monocytes
108
what classes of leukocytes are granulocytes?
eosinophils
basophils
neutrophils
109
describe neutrophils?
- most abundant leukocytes
- short lived
- major function is phagocytosis and release of cytokines/chemokynes
- first defenderes against pathogens
- quick responder
- lobed nucleus
- increased numebr occurs during inferctions and tissue injury
-neutrophilia
110
describe eosinophils?
- major function is phagocytosis of parasites
- short liveed in circulation but live longer when infiltrated into tissue
- allergy and asthma
- characterized by the presence of cytoplasmic granuoles containing histamine, RNases and other proteins that are released following activation
- eosinophilia
111
describe basophils?
- least common
- large cytoplasmic granuoles
- bi-lobed nucleus
- function similarly to eosinophils
- produce large amounts of chemotactic factors
112
describe monocytes?
- major function is phagocytosis, antigen presentation, cytokine production and cytotoxicity
- largest leukocyte
- ammeboid in shpe and unilobar nucleus
- immature circulating agranulocyte that can infiltrate into tissues becoming macrophages or dendrite cells
- often second leukocyte to respond to injury
113
describe lymphocytes?
- comprising T cells, B ccells, natural killer
- arise from different lineage cells (lymphoid progenitor cells)
- adaptive immune system
- large nucleus
- major functions include cell-mediate killing, lymphocyte activation, cytokine production, antigen recognition, memory/tolerance
- long life span
- activated by innate immune cells
- difficult to differentiate between different types of lymphocytes
114
describe T-lymphocytes?
- mature in thymus
- can promote inflammation (effector T cell)
- can decrease inflammation (regulatroy T cells)
- CD4+ ( T helper cells)
- CD8+ (T cytotoxic cells)
115
describe B-lymphocytes?
- antibody production
- secretes cytokines, chemokines
- matures in bone marrow, but named after the bursa of fabricius
- can promote inflammation ( effector B cells)
- can suppress inflammation (regulatory B cells)
116
what is leukemia?
a cancer beginning in the bone amrrow leading to high number sof abnormal leukocytes
117
what are the 4 types of leukemia?
- acute lymphoblastic leukemia (young children, lymphoblast affected)
- actue myeloid leukemia (myeloidblast affected, adults)
- chronic lymphocytic leukemia ( affects B cells, adults over 55)
- chronic myeloid leukemia ( myeloid blast or stem cell affected, adults)
118
what is a lymphoma?
start in immune cells, but a lymphoma is located within lymph nodes and or other tissues
- hodgkid and non-hodgkin
119
what are platelets?
fragments of cells that are shed from the edges of bone marrow-bound megakaryocyte
- lack nuclei but contain organelles and cytoplasmic enzymes what is haemostasis?
120
what increases the number of megakaryocytes?
thrombopoietin (produced in liver)
121
what stimulates platelet production?
thrombopoietin
122
what is haemostasis?
the arest of bleeding from a broken blood vessel
occurs unknowingly and unwillingly from capillaries, arterioles and venuoles
123
what are the 3 major steps of haemostasis?
- vascular spasm
- formation of platelet plug
- coagulation
124
describe the formation of the platelt plug?
- platelets adhere to and are activated by the exposed collagen at the site of vessel injury
- activated platelets released ADP and throboxane A2
- these chemical messengers work together to activate other passing platelets
- newly activated platelets aggregate onto growing platelte plug and release even more platlet attracting chemicals
- normal endothelium releases prostacyclin and nitric oxide, which inhibit platelet aggregation, so platelet plug is confined to site of injury
125
what does the platelet plug do?
- serves as a physical barrier
- secretes chemicals that serve as powerful vasoconstrictors
- enhances blood coagulation cascade
126
what are the roles of thrombin in clotting?
- stimulates conversion of fibrinogen to fibrin
- activates factor stabilizing fibrin meshwork of clot
- enhances activation of more prothrombin into thrombin through positive feedback
127
describe the feed backs of thrombin;
1:
stimulates conversion of fibrogenin to fibrin - loose fibrin meshwork
activates Factor XIII - stabilized fibrin meshwork
2:
enhances platlet aggregation - secrets platlett factor 3 - secretes other clotting factors - secrets prothrombin which activates thrombin
128
what is fibrinogen?
a soluble plasma protein produced in the liver and convered to fibrin by thrombin
129
what type of feedback mechanism is thrombin?
positive
130
ehy is it important to regulate thrombin levels?
if unregulated blood would always coaggulate
131
describe the intrinsic pathway during tissue damage?
- damage - activate factor XII (hageman) - activate factor XI - activate factor IX - activate factor X - activate thrombin loop
132
describe the extrinsic pathway during tissue damage?
damage - activate tissue thromboplastin (factor III) - activate factor X - activate thrombin loop
133
when do the intrinsic and extrinsic damage patwhays intertwine?
when activating factor X
134
when a repair has occured, what dissolves the clot?
plasmin (a plasma protein derived from the inactive precursor plasminogen)
135
what is the function of plasmin?
to continually prevent inappropriate clot formation
136
what activates plasminogen to plasmin?
tissue plasminogen factor
137
tissue plasminogen activator can be used for___
unblocking coronary or cerebral blood clots
138
what is tPA used to treat?
pulomary embolism, myocardial infarction, ischemic stroke
139
what is a thrombus?
a intravascular clot attached to a vessel wall
140
what is a free-floating clot?
embolus
141
what is a thromboembolism?
an obstruction of a blood vessel by a clot that has dislodged from another site in circulation
142
what is a pulmonary embolism?
a blockage in a pulmonary artery within the lungs ( almost always occurs in conjunction with deep vein thrombosis)
143
what is haemophilia?
caused by a deficiency in one or more of the factors in the clotting cascade
- hereditary
- impaired clotting ability
- more common in males
- haemophilia A: clotting factor VIII deficiency
- haemophilia B: clotting factor IX deficinecy
144
what is thrombocytopenia?
when there is a decrease in thrombocytes
- often asymptomatic but can experience external bleeding, bruising, purpura, fatigue, slow blood clotting
- can result from either a loss of platelets or a defect in production
145
what is the role of the immune system?
recognizing tissue damage and initiating recovery and pair
146
what is bacteria?
- large, unicellular
- self-equipped with all cellular machinery required for their own survival and reproduction
- can cause tissue damage in a host by releasing toxins and/or resulting in physical damage
147
what is virulencce?
the pathogenic/disease potential of pathogen
148
what are viruses?
- small
- consist of only single nucleic acids
- encased in a protein coat
- lack machinery for energy production, protein synthesis and the ability to self replicate
- invasion of a host allows the virus to feed off the host's energy resources while the viral nucleic acids direct the host's cell to synthesize viral proteins necessary for viral replication
149
what is the body's external defense?
the skin
150
what is the purpose of sweat glands?
release a dilute salt solution and other chemical that are generally toxic to bacteria
151
what is the immune cells in skin?
langerhan cells which migrate from bone marrow
152
dendritic cells are susceptible to _____ death leaving the skin vulnerable to microbial invasion or invading cancer cells
UV
153
what are keratinocytes?
- produce keratin
- form a hard protective layer as they die
- can produce cytokines which can influence T cell activation
154
what is the purpose of saliva?
contains enzymes that can lyze certain bacteriaa
155
what is the purpose of urine and vaginal secretions?
they are acidic
156
what is the purpose of respiratory system?
contains several closely proximated lymphoid tissues
coated with mucus by cells of the epithelial lining and contain cillia
157
what is the macrophage for the brain?
microglia
158
what is the macrophage for the liver?
kupffer cfells
159
what is the macrophage for the kidney?
kidney macrophages
160
what is the macrophage for the spleen?
red pulp macrophages
161
what is the macrophage for the lung?
aveolar macrophages
162
what is the lymphatic system?
comprised of lymphatic vessels that carry lymph in an open system
163
where are lymphocytes concentrated?
within lymph nodes and lympatic tissues
164
what are the lymphatic tissues?
spleen
thymus
tonsils
adenoids
appendix
peyer's patches
165
why are lymphoid tissues placed so strategically?
to intercept invading microbes before they enter circulation
166
what is the function of the lympatic tissue in the bone marrow?
site of maturational processing for B lymphocytes
167
what is the function of the lympatic tissue in the lymph nodes, tonsils, adenoids, appendix, etc...?
exchange lymphocytes with the lymph
resident lymphocyte produce antibodies and sensitized T cells which are released into the lymph
resident macrophages remove microbes and other particulate debris from the lymph
168
what is the function of the lympatic tissue in the spleen?
excahnegs lymphocytes with the blood
resident lymphocytes produce antibodies and sensitized T cells which are released into the blood
resident macrophages remove microbes and other particulate debris (worn out RBS) from the blood
stores a small percentage of RBCs which can be added to the blood by spelnic contraction as needed
169
what is the function of the lympatic tissue in the thymus?
site of maturational processing for T lymphocytes
secretes thymosin
170
what are the general traits of the receptors of the innate immune system?
primitive
broad
conserved
always present
171
what is the innate immune system?
- recognizes general classes of pathogens
- it is fast acting and immediately attempts to destroy the pathogen
- short in duration
- if the pathogen is not destroyed it will contain the infection and recruit the adaptive immune system
- non-self discriminating
- low potency
- no memory (will attack the same with repeated exposure)
172
what are the components of the innate immune system?
- physical and chemical barriers
- phagocytic leukocytes (macrophages, dendritic cells, neutrophils)
- dendritic cells
- NK cells
- complement
173
what is the most common receptor in the innate immune system?
TLR4
174
what is inflammation?
- a localized physical condition in which part of the body becomes reddened, swollen, hot, and often painful, especially as a reaction to injury or infection
- a response consisting of altered patterns of blood flow, an influx of phagocytic and other immune cells, removal of foreign antigens and healing the damaged tissues
175
during inflammation, what happens to the arterioles and capillaries?
arterioles: vasodilation
capillaries: vasodilation and increased permeability
176
describe the feedback mechanism of inflammation;
tissue damage - histamine release by mast cells - arteriole vasodialation & increased capillary permeability - increased blood delivery to injury & accumulation of ISF - increased plasma proteins & phagocytes - phagocyte secretions - defense & systemic responses (fever, etc)
177
how do lymphocytes migrate into tissues?
lymphocytes on the surface roll and tether to the lumen by selectins on the surface of endothelial cells and integrins on the surface of the lymphocyte
the lymphocyte activates and results un firm adhesion by chemokines
diapedesis occurs
178
what is phagocytosis?
a form of endocytosis involving the capture and digestion of foreign particles
eliminates debris and pathogens
dependent upon the actin myosin system
highly efficient
179
what do opsonins do?
bind to foreign substancdes to increase the baility of phagocytes to adhere
180
what are some examples of opsonins?
C3b, lectins, antibodies
181
what are the receptors for phagocytoisis?
on the surface of phagocytes
bind to opsonins and increase phagocytosis
182
how do phagocytes die?
everntually die from accumulation of toxic by products
183
describe the pahgocytosis process;
1: the macrophage attaches to a bacterial cell as the plasma membrnae surrounds it (eats it) via a TLR
2: the bacterial cell becomes internalized in a phagosome
3: lysosomes fuse with the phagosome forming a phagolysosome
4: inside the phagolysosome, the bacterial cell is killed and digested by lysosomal enzymes and toxic products
5: it ends with the elimination of bacterial debris during egestion or cell death
184
what are cytokines?
secreted products from leukocytes
they are signalling molecules and facilitate communication between cells of the immune cells
they ahve pro and anti inflammatory actions and can act in paracrine or autocrine
most common: interleukins and colony-stimulating factors
185
what is nitric oxide?
secreted by phagocytes
toxic to microbes and results in DNA damage
free radical and important in signalling molecules
vasodilator with a short halflife in blood
synthesized by NO synthase enzymes (inos (inducible), enos (endothelial), nnos (neuronal))
186
what are the 3 important cytokines?
IL-1
IL-6
tumor necrosis factor
187
in what diseases are cytokines targeted?
rheumatoid arthritis
lupus
MS
inflammatory bowel disease
cancers
stroke
psoriasis
188
what are biological drugs?
substance or product made from living organism used to prevent, diagnose or treat diseases
includes: antibodies, interleukines, fusion proteins, vaccines
189
what are monoclonal antibody treatments?
binds target proteins on cells and can stimulate the patients immune cystem to attack cells
190
what are some examples of monoclonal antibody drugs and their disease targets?
rheumatoid arthritis and IBD - remicade, humeria
MS - tysabra, rituxian, zenapax, lemtrada
alzheimers - bapineuzumab
191
how are monoclonal drugs created?
injecting a mouse host with an antigen and harvesting their B cells
the B cells are combined with myeloma cells to create a hybridoma
192
what is the tumor necrosis factor?
pro-inflammatory cytokine secreted by monocytes/macrophages, lymohocytes and NK cells
they are DYSregulated in most inflammatory diseases
193
what are NSAIDS?
non steroidal anti-inflammatory drugs
they inhibit cyclooxygenase enzymes thereby decreasing synthesis of prostaglandins and throboxanes from arachidonic acid
194
what are glucocorticoids?
destroys lymphocytes and decreases Ab production
potent and can increases risk of infection
inhibits antibody production
195
what are some examples of NSAIDS?
asprin
ibuprofin
naproxen
196
what is an example of glucocorticoid?
methylprednisolone
197
describe the arachidonic pathway
phospholipase A - archidonic acid can be split into
1: 5-lipoxygenase into leukotrienes (lipo-oxygenase pathway)
2: COX1 and COX2 into throboxanes and prostaglandins
198
what effect does steriod drugs have on the arachidonic pathway?
blocks the synthesis of phospholipase A
199
what effect does asprin have on the arachidonic pathway?
cyclo-oxygenase pathway
blocks the synthesis of COX-1 and COX-2
200
what effect does montelukast have on the arachidonic pathway?
lipo-oxygenase pathway
blocks the interaction between leukotriene molecules and their receptors
201
what are interferons?
released from virally-infected cells and interfered with viral replication
interferons bind with receptors on neighboring cells but do not have a direct anti-viral effect, instead they trigger production of virus-blocking enzymes and inhibit protein synthesis
inhances phagocytic activity, stimulate antibody production and stimulates release of pro-inflammatory cytokines
have anti-cancer effects and enhances the pro-killing ability of NK cells and cytotoxic T cells
202
what are the 2 classes of interferons and how are they produced?
type 1:
by fibroblasts and monocytes (IFNalpha, IFNbeta)
type 2:
by T-helper cells (IFNgamma)
203
describe the method/feedback mechanism of an interferon preventinf viral replication;
1: the vrius enters a host cell
2: the virus replicates in the invaded cell
3: the cell releases an interferon
4: the interferon binds with receptors on uninvaded cells
5: uninvaded cells produce inactive enzymes that are capable of breaking down viral messenger RNA and inhibiting protein synthesis
6: a virus enetrs the cell acted upon by the interferon
7: virus blocking enzymes are activated
8: virus cannot multiply in the newly invaded cell
204
what is the complement system?
a defense mechanism that "complements" the action of antibodies and can be activated by:
1: specific carb chains present on the surface of microorganisms (innate)
2: exposure to antibodies produced against a particular antigen (adaptive)
205
how does the complement system work?
a sequence of reactions that result in a donut hole protein complex
the membrnae attack complexes abd forms "holes" in the infected cells
results in the osmotic flow od water into the cell causing swelling and lysis
206
what is adaptive immunity?
an immune response that results in a selective attack aimed at limiting and neutralizing an antigen that has been previously exposed to the host
207
what are the 2 classes of adaptive immunity?
1: cell-mediated
2: antibody-mediated
208
does the adaptive immune system remeber diseases?
yes
209
describe teh differentation of T and B cells and their responses for the adaptive immune system;
a hemopoietic precursor cells differentiates in the bone marrow into bone marrow lymphocytes before splitting in the following;
1: heads to the thymus where they mature into T cells - head into peripherial lymphoid tissues and lymphnodes.
when invaded by a foreign body, they result in a cell mediated response
2: in the bone marrow some mature into B cells where they ehad into peripherial lymphoid tissues and lymph nodes
when invaded by a foreign body, they result in an antibody mediated response
210
what are CD antigens?
cluster of differentation antigens
often serve as both receptors and ligands involved in cell signalling
measuredvia immunohistochemistry or flow cytometry
can be used to identify different types and ratios of immune cells
211
what CD marker is expressed on all stem cells?
CD34
212
what CD marker doed CD34 split into?
CD45
213
what CD marker represents a granulocyte?
CD15
214
what CD marker representes a monocyte?
CD14
215
what CD marker represents a T-lymphocyte?
CD3
216
what CD marker represents a B-lymphocyte?
CD19
217
what CD marker represents a thrombocyte?
CD61
218
a T-lymphocyte can be a helper, activated or a cytotoxic lymphocyte, what markers identify these?
helper: CD4
cytotoxic: CD8
activated: CD25
219
what are B-lymphocytes?
contain B cell receptors on the surface that bind either an individual or multitude of antigens
220
antigens simulating B cells often result in the conversion of a B cell to?
a plasma cell
221
besides a plasma cell, B cells can also differentiate into _____--
memory cells
222
what are plasma cells?
larger than B cells
swell as the ER expands
relatively short lived
223
an antibody can also be called _____
gamma globin
immunoglobin (Ig)
224
what are the subclasses of antibodies?
IgG
IgM
IgD
IgA
IgE
225
what are IgG 's?
most abundant in blood
produce the most specific immune responses againts bacteria and viruses
226
what are IgA 's?
found within secretions of the digestive, respiratory and geniturinary systems, milk and tears
227
what are IgM 's?
serves as b cell surface receptor for antigen attachment
secreted at early stages of response
228
what are IgD 's?
function is uncertain
on surface of many B cells
229
what are IgE 's?
protects against parasitic worms
mediator of common allergic responses
230
all antibodies perform _____
1: bind antigens
2: activate the compliment cascade
3: neutralize bacterial toxins
4: inhibit bacteria and virus entry into cells
5: assisting phagocytosis
6: aid cytotoxicity of T and NK cells
231
what is the structure of an antibody?
2 heavy chains
2 light chains
232
where is specificity of the antibody located?
within the antigen-binding fragments
unique for each different antibody
233
what does the constant fragment of an antobody do?
mediates antibody induced activity
234
what do antibodies do?
physically hinder antigens and amplify innate immune responses
mark foreign antigens as targets for destruction by the complement system, phagocytes, NK cells
235
what is neutralization?
antibodies binding to antigens and preventing these chemicals or vruses from interacting with susceptible target cells
236
how does Ab cross linking occur?
via multiple Ag-Ab interactions into chains/lattices
237
what happens if large amounts of Ag-Ab complexes are not destroyed?
they can damage tissues and cells and results in immune complex disease
238
describe the amplification of the innate immune system response via antibodies;
1: when antibodie binds to antigen, C1 is activated and activates the cascade. Ab-Ag is highly specific, teh downstream complement cascade is identicle within the different subclasses
2: antibodies (mainly IgG) act as opsonins to enchance phagocytosis by binding Fc receptors on phagocytes
3: NK cells attach and destroy Antibody coated cells
239
when are diverse B cells produced?
during fetal development
240
each B cell responds to _ antigen
1
241
what does the clonal selection theory propose?
how a matching B cell responds to its antigen
when antigen binds to BCR, B cells proliferate into clones whihc is commited to producing the same antibody.
clones ccan further differentiate into plasma cells
242
during infection, what class of antibodies are produced first?
IgM
243
describe the initial immune response;
- initial contact with antigen results in delayed antibody responses
- after peak, antibody levels decline
- responsible for long term immunity
- primary exposure can occur during infection of vaccination
- some diseases do not result in the formation of memory B cells
244
what is the re-exposure respose? (secondary)
if re-exposure occurs, the secondary response is much quicker, more potent, longer lasting sue to memory B cells
245
what is V(D)J recombination?
BCRs and antibodies are proteins that are transcribed and translated by individual genes
they are highly prone to mutations in gene regions encoding the variable regions, thus giving rise to diversity
246
Light chains are responsible for which recombination letters?
V and J
247
heavy chains are responsible for which recombination letters?
V, D, J
248
what is active immunity?
the production of antibodies as a result of exposure to an antigen
249
what is passive immunity?
the transfer of antibodies that were actively formed from a host to a recipient
250
what is an example of passive immunity?
IgG and IgA antibodies passed to fetus during pregnancy
251
what is serum sickness?
when an individual may develop an immune response against the injecfted antiserum
252
what are T-lymphocytes?
- T cells can identify intracellular foreign oathogens/antigens that reside within cells and do so in direct contact by releasing cytokines and molecules that destroy the infected cell
- clonal and hughly antigen specific
- T cells express unique T cell receptor
- immature T cells require TCRs in the thymus
- during development, t cells learn to recognize self vs non self
- CD3 is the T cell co receptor that helps activate the T cell
253
what is positive vs negative selection?
the ability to recognize self vs nonself
254
what are cytotoxic T cells?
CD8
destroys the host cells harbourinf foreign antigen and or mutate proteins by releasinf granzymes and perforin molecules, which target the cell's membrane and form pore like channels
255
what are helper T cells?
CD4
secrete cytokines that augment the immune response; many different subtypes and extremely complex
IL-4, IL-5, IL-6 = maturing B cells
IL-1 IL-2 = recruit and activate macrophages
IL-2 = help stimulate T cell activation/proliferation
256
what is immune tolerance?
an immunological term referring to the inability of a host's immune system to attack self antigen
largely occurs during lymphocyte development
256
what are the things responsible for immune tolerance?
clonal deletion
clonal anergy
receptor editing
regulator T cells
immunological ignorance
immune privilege
256
describe teh activation of helper T cells by antigen presentation;
1: bacterium is taken up by phagocytosis and degraded by a ysosome
2: bacterial antigenic peptides are displayed on APC cells surface bound to class 2 MHC proteins and presented to T cells with TCRs that recognize teh antigen
3: APC secretes interleukins which activates the T cell
4: activated T cell secretes cytokines, which stimulate T cell to ptoliferate and expand clone of selected cells
5: cloned helper T cells are ready to activate B cells and enhance otehr immune activities
257
what is clonal deletion?
apoptosis of immature cells that would react with proteins foudn within the body
258
what is clonal anergy?
a backup for clonal deletion and inactivation of T ccells as a result of being exposed to self antigen
259
what is receptor editing?
when a B cell rearranges its B cell receptor gene after recognizing self
260
what is regulator T cells?
suppressor T cells that inhibit the typical effetor T cell response
261
what is immunological ignorance?
occurs when self proteins are normally hidden from the immune system
262
what is immune privilege?
adapted through evolution to protect viral structures from the damaging effects of inflammation and immune system
it is the idea that tissues or cells can tolerate the introduction of antigens without eliciting an inflammatory response
263
where are MCH (major histocompatibility complexes) located?
on the surface of cells and escort engulfed foreign antigen to the cell surface for presentation
264
what are the classes of MCH?
class 1 and class 2
265
cytotoxic T lymphocytes respond to what class of MCH?
class 1
they are found on the surfaced of every cell
if infected, the cytotoxic T lymphocyte will bind to the infected host cell via MCH class 1
266
MCH class 2 expression is restricted to ____
specific immune cell types it is the site where CD4 helper cells interact
267
what is autoimmunity?
occurs when the immune system fails to distinguish itself from nonself and results in an attack of self proteins or peptides
1: exposure of a normally inaccesible self antigen, since the body was never previously exposed to it and views the antigen as foreign
2: modification of self antigens by factors within the environment
3: exposure to antigens that mimic self sntigen
268
most mutations do not result in malignancy due to ___-
1: very few mutations occur in genes that govern cell growth and division
2: multipke independent mutations are often required for a cell to become cancerous
3: immune system targets the cancer cell early in their development
269
what are the 3 types of immune cells that participate in immune surveillance?
cytotixic T cells, NK cells, macrophages
270
what is immunodeficiency?
results when the immune system fails to respond adequately to foreign invasion and involves humoral and or cell mediated immunity
271
what is severe combined immunodeficieny?
a rare genetic disorder where T and B cells are lacking.
required to live in a bubble
272
what are allergies?
inappropriate immune attack/reactivity to a harmless environmental substance
273
what is an allergen?
can vary from a minor irritant to a sever or fatalreaction, can activate a T or B cell response
274
allergic responses can result in;
1) immediate hypersensitivity
2) delayed hypersensitivity
275
what is immediate hypersensitivity?
allergens = pollen, grains, bees, penicillin, etc
bind and elicit the synthesisi of IgE antibodies
upon exposure helper T cells secrete IL-4 which stimulates IgE production by plasma cells
because IgE is membrane bound, when an antigen binds the cells release histamines which is packaged in preformed granuoles
histamine results in vasodilation
276
what induces prolonged and pronounced smooth muscle contraction in the respiratory system?
slow reactive substance of anaphylaxis
277
what attracts eosinophils and inhibits histamine release?
eosinophil chemotactic factor
278
what is anaphylaxis?
a life threatening system reaction that can occur if an allergen becomes blood borne or if large amounts of mediators are released into circulation
can cause severe hypotension resulting from widespread vasodialation and shift of plasma fluid into the interstitial spaces as a result of increase capillary permeability
279
delayed hypersensitivites are mediated via _____
T cells (poision ivy, cosmetics. cleaning agents, etc....)
